HK1208646B - Additive manufacturing system with extended printing volume, and methods of use thereof - Google Patents

Description

Additive manufacturing system with extended print volume and method of using same

Technical Field

The present disclosure relates to an additive manufacturing system for building a three-dimensional (3D) part using layer-based additive manufacturing techniques. More particularly, the present disclosure relates to an additive manufacturing system for printing large 3D parts, and a method of printing 3D parts in an additive manufacturing system.

Background

Additive manufacturing systems are used to print or otherwise construct 3D parts from digital representations (e.g., AMF and STL formatted files) of 3D parts using one or more additive manufacturing techniques. Examples of commercially available additive manufacturing techniques include extrusion-based techniques, spraying, selective laser sintering, powder/binder spraying, electron beam melting, and stereolithography processes. For each of these techniques, the digital representation of the 3D part is initially cut into a plurality of horizontal layers. For each cut layer, one or more tool paths are then generated that provide instructions for a particular additive manufacturing system to print the formulated layer.

For example, in an extrusion-based additive manufacturing system, a 3D part may be printed from a digital representation of the 3D part in a layer-by-layer manner by extruding a flowable part material. The part material is extruded through an extrusion tip or nozzle carried by a print head of the system and is deposited as a series of paths on the substrate in the x-y plane while the print head moves along the tool path. The extruded part material fuses to the previously deposited part material and solidifies upon a decrease in temperature. The position of the printhead relative to the substrate is then raised along the Z-axis (perpendicular to the x-y plane), and the process is then repeated to form a 3D part similar to the digital representation.

In fabricating 3D parts by depositing multiple layers of part material, a support layer or structure is typically built underneath the overhang of the 3D part being built or in a cavity thereof, these parts not being supported by the part material itself. The support structure may be constructed using the same deposition technique as the component material is deposited. The host computer generates additional geometry that acts as a support structure for the overhang or free space segment of the 3D part being formed. The support material is then deposited with the second nozzle in accordance with the generated geometry during printing. The support material adheres to the part material during manufacturing and can be removed from the finished 3D part when the printing process is complete.

Disclosure of Invention

One aspect of the present disclosure relates to an additive manufacturing system for printing 3D parts, and a method of using the system. The system includes a heating mechanism configured to heat a region (e.g., a chamber or other region) of the system to one temperature or more; a printhead configured to print component material along a non-vertical printing axis. The system further includes a non-horizontal receiving surface configured to receive printed part material from the print head in the heated region to produce a three-dimensional part in a layer-by-layer manner; and a drive mechanism configured to guide the receiving surface along the non-vertical printing axis such that the receiving surface and at least a portion of the three-dimensional part move out of the heated region.

Another aspect of the present disclosure relates to an additive manufacturing system for printing 3D parts and a method of using the same, wherein the system comprises a plurality of sequential chambers that can be heated to different temperatures to define a stepped down temperature gradient. The system also includes a print head disposed in a first chamber of the plurality of sequential chambers, the print head configured to print the part material along a non-vertical printing axis, the non-horizontal receiving surface configured to receive the printed part material from the print head in the heated region to produce the 3D part in a layer-by-layer manner. The system also includes a drive mechanism configured to guide the receiving surface along a non-vertical printing axis such that the receiving surface and at least a portion of the 3D part pass through a plurality of successive chambers with a stepped-down temperature gradient.

Another aspect of the present disclosure relates to a method for printing a 3D part with an additive manufacturing system. The method includes heating an area of an additive manufacturing system and printing the 3D part and the skeleton on a receiving surface in a layer-by-layer manner along a non-vertical printing axis, preferably in the heated area. The method also includes guiding the receiving surface along a printing axis in coordination with printing the 3D part and the skeleton such that the receiving surface, at least a portion of the 3D part, and at least a portion of the skeleton preferably move outside of the heated region.

Definition of

Unless otherwise defined, the following terms used herein have the meanings provided below:

the terms "about" and "approximately" are used herein to refer to measurable values and ranges due to desired variables (e.g., limitations and variability in measurements) known to those skilled in the art.

Directional orientations such as "above," "below," "top," and "lower" are used to refer to directions along a printing axis of a 3D part. In embodiments where the printing axis is a vertical z-axis, the layer printing direction is an upward direction along the vertical z-axis. In these embodiments, the terms "above," "below," "top," and "lower," etc., are based on the vertical z-axis. However, in embodiments where layers of a 3D part are printed along one different axis, such as along a horizontal x-axis or y-axis, the terms "above," "below," "top," and "lower," etc., are relative to the given axis. Furthermore, in embodiments where the printed layer is planar, the printing axis is perpendicular to the build plane of the layer.

The term "printed on … …," such as "printing a 3D part on a print substrate," includes direct and indirect printing on a print substrate. "direct printing" refers to depositing a flowable material directly on a print substrate to form a layer that adheres to the print substrate. In contrast, "indirect printing" involves depositing a flowable material on an intermediate layer that is printed directly on the receiving surface. As such, printing the 3D part on the print substrate may include: (i) a case where the 3D part is printed directly on the print substrate, (ii) a case where the 3D part is printed directly on an intermediate layer (e.g., on an intermediate layer of the support structure), where the intermediate layer is printed directly on the print substrate, and (iii) a combination of cases (i) and (ii).

The term "providing", such as "providing a chamber", etc., when recited in the claims, is not intended to require the transmission or reception of any particular provided item. However, for the purposes of clarity and ease of reading, the term "provided" is merely used to refer to the item referred to in the subsequent elements of the claims.

Drawings

Fig. 1A is a side view of a 3D part being printed with a support mechanism and skeleton, showing a vertical printing axis.

Fig. 1B is a side view of a 3D part being printed with a support mechanism and skeleton, showing a horizontal printing axis.

Fig. 2 is a top view of a first exemplary additive manufacturing system having a platen and platen gantry for printing 3D parts horizontally according to the present disclosure.

FIG. 3 is a side view of a first exemplary system.

Fig. 4A is a perspective view of a 3D part, support structure, and skeleton printed on a platen.

Fig. 4B is an exploded perspective view of the 3D part, support structure, and skeleton printed on the platen.

Fig. 5 is a side view of a first exemplary system showing a 3D part being printed horizontally.

Fig. 6 is a top view of a second exemplary additive manufacturing system having a platen actuator for printing 3D parts horizontally according to the present disclosure.

FIG. 7 is a side view of a second exemplary system.

FIG. 8A is a perspective view of a 3D part, support structure, and skeleton printed on a platen actuator.

FIG. 8B is an exploded perspective view of the 3D part, support structure, and skeleton printed on the platen actuator.

Fig. 8C is a perspective view of a 3D part, support structure, and skeleton printed on a platen actuator, showing an alternative drive mechanism.

Fig. 9 is a side view of a second exemplary system showing a 3D part being printed horizontally.

Fig. 10 is a top view of a third example additive manufacturing system with a wedge actuator for printing 3D parts horizontally according to the present disclosure.

FIG. 11 is a side view of a third exemplary system.

FIG. 12 is an enlarged side view of a wedge actuator illustrating a technique for printing a support structure.

FIG. 13A is a perspective view of a 3D part, support structure, and skeleton printed on a wedge actuator.

FIG. 13B is an exploded perspective view of a 3D part, support structure, and skeleton printed on a wedge actuator.

Fig. 14 is a side view of a third exemplary system showing a 3D part being printed horizontally.

FIG. 14A is a side view of an alternative to the third exemplary system (or any other exemplary system) that includes a rotating band mechanism having one or more wedge actuators.

Fig. 14B is an exploded perspective view of one of the wedge actuators positioned to receive printed material.

FIG. 14C is a side view of a post-printing processing assembly using a rotating tape mechanism.

Fig. 14D is a side view of an exemplary support removal station of the post-printed processing assembly.

Fig. 14E is a side view of a second alternative of the third exemplary system (or any other exemplary system) that includes an auger-based viscous pump printhead.

Fig. 14F is a side schematic view of an exemplary auger-based viscous pump printhead.

Fig. 14G is a side view of a second alternative of the third example system (or any other example system) that includes a plurality of auger-based viscous pump printheads.

Fig. 15 is a side view of a fourth example additive manufacturing system of the present disclosure having a wedge actuator for vertically printing a 3D part.

Fig. 16 is a side view of a fourth exemplary system showing a 3D part being printed vertically.

Fig. 17 is a side view of a fifth example additive manufacturing system of the present disclosure having a plurality of chambers for providing a plurality of temperature zones.

Fig. 18A is a front view of a horizontally printed thin-walled 3D part with a skeleton.

Fig. 18B is a front view of a plurality of horizontally printed thin-walled 3D parts with a skeleton, where the plurality of 3D parts are printed laterally adjacent to one another.

Fig. 18C is a front view of a plurality of horizontally printed thin-walled 3D parts with a plurality of backbones, wherein the plurality of 3D parts are printed adjacent to one another in a stacked arrangement.

Fig. 19 is a rear perspective view of a vertically printed thin-walled 3D part with a skeleton.

20A and 20B are perspective views of a plurality of 3D parts, support structures, and skeletons printed on a wedge actuator, illustrating a skeleton technique for printing a plurality of consecutive 3D parts.

Fig. 21 is a top view photograph of an exemplary wing component with a support mechanism and a skeleton printed horizontally.

FIG. 22 is a front view photograph of an exemplary thin-walled panel with a skeleton printed vertically.

FIG. 23 is a rear view photograph of an exemplary thin-walled panel with a skeleton printed vertically.

Detailed Description

The present disclosure relates to an additive manufacturing system with extended print volume for long or tall 3D parts. The additive manufacturing system includes a heating mechanism configured to heat a build area of the system, such as a chamber having a port open to ambient conditions outside the chamber. The system also includes one or more printheads configured to print the 3D part on a print substrate (e.g., a platen or other part having a receiving surface) in a layer-by-layer manner in a heated cavity or other build region by a substrate platen.

As the printed 3D part grows on the print substrate, the print substrate may be guided (index) or otherwise moved through the port. The printed 3D part may continue to grow out of the port until the desired length or height is reached. The use of the above-described ports expands the printable volume along the printing axis of the system, allowing long or tall 3D components, such as wings, manifolds, fuselages, etc., to be printed in a single printing operation. Thus, the 3D part may be larger than the size of the additive manufacturing system.

As explained further below, the additive manufacturing system may be configured to print the 3D part in a horizontal direction, a vertical direction, or along other orientations (such as a ramp relative to the horizontal and vertical directions). In each of these embodiments, the multiple layers of the printed 3D part may be stabilized by one or more printed "building frames or skeletons" (scaffold) that support the 3D part laterally with respect to the printing axis of the system to handle or provide forces parallel to the build plane. This is compared to a printed "support structure" as follows: the support structure supports the bottom surface of the 3D part relative to the printing axis of the system to provide a force perpendicular to the build plane (e.g., to act as an anchor for subsequent printed layers to reduce distortion and curling).

For example, fig. 1A is a simplified elevation view of a 3D part 10 being printed in a layer-by-layer manner from printhead nozzles 12, where multiple layers of the 3D part 10 are grown along a vertical z-axis. Thus, the "print axis" in FIG. 1A is the vertical z-axis, with each layer extending parallel to the horizontal x-y build plane (the y-axis not shown).

The multiple layers of 3D part 10 are printed on the multiple layers of support structure 14, which layers of support structure 14 are correspondingly disposed on platen 16. Support structure 14 includes a first series of printed layers 14a, which printed layers 14a support bottom surface 10a of 3D part 10 along a printing axis (e.g., along a vertical z-axis), thereby providing a force perpendicular to the build plane. Layer 14a facilitates bonding 3D part 10 to platen 16 or other suitable printed substrate in order to reduce the risk of curling layer 14a while also allowing 3D part 10 to be removed from platen 16 without damaging 3D part 10. In addition, support structure 14 includes a second series of printed layers 14b, which printed layers 14b support overhanging surface 10b of 3D part 10 along a printing axis. In each case, the multiple layers (e.g., layers 14a and 14b) of support structure 14 support the bottom surface (e.g., bottom surfaces 10a and 10b) of 3D part 10 along the printing axis, thereby further providing a support force perpendicular to the build plane.

In contrast, the multiple layers of the armatures 18a and 18b are printed in lateral positions relative to the 3D part 10 and are not used to support the bottom surfaces 10a and 10 b. However, the skeletons 18a and 18b, which are shown as tubular skeletons extending along the z-axis, are printed to support lateral sides of the 3D part 10 to act as buttresses (buttons) that provide forces parallel to the build plane. For example, in some cases, such as when the 3D part 10 is tall and narrow, the adhesion between the layer 14a and the 3D part 10 may not be sufficient to prevent the uppermost layer of the 3D part 10 from shaking during the printing operation. Wobble of the 3D part 10 may reduce the fit or alignment between the printhead nozzles 12 and the 3D part 10, potentially resulting in reduced printing accuracy. However, the skeletons 18a and 18b provide a suitable mechanism to support the 3D part 10 at one or more lateral positions relative to the print axis (i.e., vertical z-axis) to stabilize the 3D part 10 against wobble.

Optionally, fig. 1B shows 3D part 20 being printed from printhead nozzles 22 in a layer-by-layer manner, where multiple layers of 3D part 20 are grown horizontally along the z-axis. In this way, the "print axis" in fig. 1B is the horizontal z-axis, with each layer extending parallel to the vertical x-y build surface (the y-axis is not shown).

In this case, multiple layers of the 3D part 20 are printed on multiple layers of the support structure 24, which layers of the support structure 24 are correspondingly disposed on the platen 26. Support structure 24 includes a first series of printed layers 24a, which printed layers 24a support bottom surface 20a of 3D part 20 along a printing axis (e.g., along a horizontal z-axis); and a second series of printed layers 24b, the printed layers 24b supporting the overhanging surface 20b of the 3D part 20 along a printing axis. In each case, the multiple layers (e.g., layers 24a and 24b) of support structure 24 support the bottom surface (e.g., bottom surfaces 20a and 20b) of 3D part 20 along the printing axis to provide a force perpendicular to the build plane.

In contrast, the layers of the skeleton 28 are printed in lateral positions relative to the layers of the 3D part 20 and are not used to support the bottom surfaces 20a and 20 b. Rather, the skeleton 28 is printed to support the lateral side of the 3D part 20, which in the view shown in fig. 1B is the vertical bottom side of the 3D part 20, relative to the print axis. In this horizontal case, the skeleton 28 supports the 3D part 20, preventing the 3D part 20 from sagging in a direction parallel to the build plane under the influence of gravity during printing operations.

For example, in some cases, such as when 3D part 20 is long and narrow, the cantilevered adhesion between layer 24a and 3D part 20 may not be sufficient to prevent the most distal layer of 3D part 20 from sagging under the force of gravity during a printing operation. In this way, the skeleton 28 provides a suitable mechanism to support the 3D part 20 at one or more lateral positions relative to the printing axis (i.e., the horizontal z-axis) to reduce the risk of sagging. The skeleton 28 may then itself rest on the underlying surface 29 in the y-z plane and slide along the underlying surface 29.

For ease of discussion, the z-axis is used herein when referring to the print axis, regardless of the print direction or orientation. For a vertical printing operation such as that shown in fig. 1A, the print z-axis is a vertical axis, and each layer of the 3D part, the support structure, and the skeleton extend along a horizontal x-y build plane. Alternatively, for a horizontal printing operation such as that shown in fig. 1B, the print z-axis is a horizontal axis, and each layer of the 3D part, the support structure, and the skeleton extend along a vertical x-y build plane. In another alternative embodiment, the layers, support structures, and skeleton of the 3D part may be grown along any suitable axis.

Additionally, although fig. 1A and 1B show a flat build plane (i.e., each layer is planar), in other alternative embodiments, the layers, support structures, and/or skeleton of the 3D part may be non-planar. For example, the layers of a given 3D part may each exhibit a slight curve or curvature from a flat build plane. In these embodiments, the build plane may be determined as a general plane having the curvature. The term "build plane" is not intended to be limited to a flat plane unless explicitly stated otherwise.

As will be discussed further below, in some embodiments, the receiving surface on which the 3D part, support structure, and/or skeleton is printed may have a cross-sectional area in the build plane that is less than a footprint (footprint) area of the 3D part, support structure, and/or skeleton. For example, the receiving surface of the print substrate may have a cross-sectional area that is less than the footprint area of the desired 3D part. In this case, multiple layers of the support structure and/or skeleton may be printed with increasing cross-sectional area until they at least encompass the footprint area of the desired 3D part. This allows the use of small print substrates together with the additive manufacturing system of the present disclosure. Furthermore, this allows printing of multiple consecutive 3D parts with the skeleton as the receiving surface.

Horizontal printing

Fig. 2-14 illustrate an exemplary additive manufacturing system of the present disclosure having an extended print volume (shown in fig. 1B) for horizontally printing long 3D parts, such as for the 3D part 20 discussed above. Fig. 2-5 illustrate a system 30, which is a first exemplary additive manufacturing system for horizontally printing or otherwise building 3D parts, support structures, and/or skeletons using layer-based additive manufacturing techniques. Suitable systems for use with system 30 include extrusion-based additive manufacturing systems developed by Stratasys, Inc of Eden Prairie, minnesota under the trademarks "FDM" and "FUSED DEPOSITION MODELING" that are oriented such that the print z-axis is a horizontal axis.

As shown in fig. 2, the system 30 may rest on a table or other suitable surface 32 and include a chamber 34, a platen 36 and platen stage 38, a printhead 40, a head stage 42, and consumable assemblies 44 and 46. Chamber 34 is an enclosed environment having a chamber wall 48 and initially includes a platen 36 for printing a 3D part (e.g., 3D part 50), a support structure (e.g., support structure 52), and/or a skeleton (e.g., skeleton 54 as shown in fig. 3-5).

In the illustrated embodiment, chamber 34 includes a heating mechanism 56, and heating mechanism 56 may be any suitable mechanism configured to heat chamber 34, such as one or more heaters and an air circulator to blow heated air through chamber 34. Heating mechanism 56 may heat chamber 34 at least in the vicinity of printhead 40 and maintain chamber 34 at one or more of the following temperatures: the one or more temperatures are in a window (window) between the cure temperature and the creep relaxation temperature of the component material and/or the support material. This reduces the rate at which the component and support materials solidify after being extruded and deposited (e.g., reduces distortion and curling), where the creep relaxation temperature of the material is proportional to its glass transition temperature. An example of a suitable technique for determining the creep-relaxation temperature of the component material and the support material is disclosed in U.S. Pat. No.5,866,058 to Batchelder et al.

Chamber wall 48 may be any suitable barrier for reducing the loss of heated air from the build environment within chamber 34 and may also thermally isolate chamber 34. As shown, chamber wall 48 includes a port 58 extending transversely therethrough such that chamber 34 is open to ambient environmental conditions outside of system 30. Thus, system 30 exhibits a thermal gradient at port 58, wherein the elevated temperature or temperatures in chamber 34 are reduced to an ambient temperature outside of chamber 34 (e.g., room temperature, about 25 ℃).

In some embodiments, the system 30 may be configured to actively reduce heat loss via the port 58, such as with an air curtain, thereby improving energy savings. Additionally, system 30 may also include one or more permeable barriers, such as insulating drapery, cloth or flexible liners, bristles, or the like, located at port 58 that restrict airflow out of port 58 while allowing platen 36 to pass therethrough. In an alternative embodiment, chamber 34 may be omitted and system 30 may contain an open heatable region without chamber walls 48. For example, the heating mechanism 56 may heat the temperature of the heatable region to one or more elevated temperatures, such as with a hot air blower that directs hot air toward the printhead 40 (or near the printhead).

Platen 36 is a printing substrate having a receiving surface 36a on which 3D part 50, support structure 52, and skeleton 54 are printed horizontally in a layer-by-layer manner. In some embodiments, the platen 36 may also include a flexible polymer film or liner, or other substrate or layer, that may serve as the receiving surface 36 a. Platen 36 is supported by a platen stage 38, which platen stage 38 is a stage-based drive mechanism configured to guide platen 36 or otherwise move platen 36 along the print Z-axis. The platen stage 38 includes a platen mount 60, a guide rail 62, a screw 64, a screw drive 66, and a motor 68.

The platen mount 60 is a rigid structure that holds the platen 36 such that the receiving surface 36a is held parallel to the x-y plane. The platen mount 60 is slidably coupled to a guide rail 62 that is a linear support or bearing to guide the platen mount 60 along the z-axis and to limit movement of the platen 36 to a direction along the z-axis (i.e., to limit movement of the platen 36 in the x-y plane). The screw 64 has a first end coupled to the platen mount 60 and a second portion engaged with the screw drive 66. The screw drive 66 is configured to rotate and pull out the screw 64 to guide the platen 36 along the z-axis based on rotational power from the motor 68.

In the example shown, print head 40 is a dual-tip extrusion head configured to receive consumable filaments or other materials from consumable assemblies 44 and 46 (e.g., via guide tubes 70 and 72) for printing 3D part 50, support structure 52, and skeleton 54 on receiving surface 36a of platen 36. Examples of suitable devices for the printhead 40 include those disclosed in the following patents: U.S. Pat. Nos. 5,503,785 to Crump et al; swanson et al, U.S. Pat. No.6,004,124; U.S. Pat. Nos. 7,384,255 and 7,604,470 to LaBossiere et al; leavitt, U.S. Pat. No.7,625,200; U.S. Pat. No.7,896,209 to Batchelder et al; and Comb et al, U.S. patent No.8,153,182.

In some embodiments, the print head 40 may be an auger-based viscous pump, such as the viscous pumps disclosed in the following patents: U.S. patent nos. 5,312,224 and 5,764,521 to Batchelder et al and 7,891,964 to Skubic et al. In additional embodiments where the print heads 40 are interchangeable single nozzle print heads, examples of suitable means for each print head 40 and the connection between the print head 40 and the head carriage 42 include those disclosed in the following patents: swanson et al, U.S. patent application publication No. 2012/0164256.

The printhead 40 is supported by a head stage 42, which head stage 42 is configured to move the printhead 40 in (or substantially in) an x-y plane parallel to the platen 36. For example, the head gantry 42 may include a y-axis rail 74, an x-axis rail 76, and a support sleeve 78. The print head 40 is slidably coupled to the y-axis track 74 for movement along the horizontal y-axis (e.g., via one or more motor-driven belts and/or screws, not shown). The Y-axis rail 74 is fixed to a support sleeve 78, which support sleeve 78 is itself slidably coupled to the x-axis rail 76, allowing the printhead 40 to also move along the vertical x-axis or in any direction in the x-Y plane (e.g., via a motor-driven belt, not shown). Although the additive manufacturing system discussed herein is shown as printing in a cartesian coordinate system, the system may alternatively operate in a plurality of different coordinate systems. For example, the head gantry 42 may move the print head 40 in a polar coordinate system, thereby providing a cylindrical coordinate system for the system 30.

Suitable devices for consumable assemblies 44 and 46 include those disclosed in the following patents: swanson et al, U.S. Pat. Nos. 6,923,634; comb et al, U.S. Pat. Nos. 7,122,246; U.S. Pat. Nos. 7,938,351 and 7,938,356 to Taatjes et al; swanson, U.S. patent application publication No. 2010/0283172; and U.S. patent application nos. 13/334,910 and 13/334,921 to Mannella et al.

Suitable materials and filaments for use with the printhead 40 include those disclosed and listed in the following patent documents: U.S. Pat. Nos. 5,503,785 to Crump et al; U.S. Pat. Nos. 6,070,107 and 6,228,923 to Lombardi et al; U.S. Pat. No.6,790,403 to Priedeman et al; comb et al, U.S. Pat. Nos. 7,122,246; U.S. patent application publication nos. 2009/0263582, 2011/0076496, 2011/0076495, 2011/0117268, 2011/0121476 and 2011/0233804 to Batchelder; and U.S. patent application publication No.2010/0096072 to Hopkins et al. Examples of suitable average diameters for these filaments range from about 1.02 millimeters (about 0.040 inches) to about 3.0 millimeters (about 0.120 inches).

The system 30 also includes a controller 80, which is one or more control circuits configured to monitor and operate the components of the system 30. For example, one or more of the control functions performed by the controller 80 can be implemented in hardware, software, firmware, etc., or a combination thereof. Controller 80 may be in communication with chamber 34 (e.g., heating mechanism 56), printhead 40, motor 68, and various sensors, calibration devices, display devices, and/or user input devices via communication lines 82.

In some embodiments, the controller 80 may also be in communication with one or more of the platen 36, the platen gantry 38, the head gantry 42, and any other suitable components of the system 30. Although the communication lines 82 are shown as single signal lines, the communication lines 82 may include one or more electrical signal lines, optical signal lines, and/or wireless signal lines to allow the controller 80 to communicate with various components of the system 30. Further, while the controller 80 and communication lines 82 are shown as being located outside of the system 30, the controller 80 and communication lines 82 are desirably located in internal components of the system 30.

The system 30 and/or controller 80 may also be in communication with a computer 84, the computer 84 being one or more computer-based systems in communication with the system 30 and/or controller 80, and may be separate from the system 30, or alternatively may be an internal component of the system 30. The computer 84 includes computer-based hardware, such as data storage devices, processors, memory modules, etc., for generating and storing tool paths and associated printing instructions. Computer 84 may transmit these instructions to system 30 (e.g., controller 80) to perform the printing operation.

During operation, the controller 80 may instruct the print head 40 to selectively draw or pull successive lengths of the component and support material filaments from the consumable assemblies 44 and 46 (via the guide tubes 70 and 72). The print head 40 thermally melts these successive lengths of received filaments so that they become molten flowable material. These melted flowable materials are then extruded from the printhead 40 along the printing z-axis and deposited on the receiving surface 36a for printing the 3D part 50 (from the part material), the support structure 52 (from the support material), and the skeleton 54 (from the part and/or support material).

The printhead 40 may initially print one or more layers of support structure 52 on the receiving surface 36a to provide an additive base for subsequent printing. This maintains a good bond between the multiple layers of 3D part 50 and platen 36 and reduces or eliminates any tolerance in flatness between receiving surface 36a of platen 36 and the x-y plane. After each layer is printed, controller 80 may instruct platen gantry 38 to guide platen 36 in the direction of arrow 86 in single layer increments along the z-axis.

After support structure 52 is initially printed, printhead 40 may then print the multiple layers of 3D part 50 and skeleton 54 and optionally any additional multiple layers of support structure 52. As described above, the multiple layers of support structure 52 are intended to support the bottom surface of 3D part 50 along the printing z-axis against curling forces, and the multiple layers of skeleton 54 are intended to support 3D part 50 along the vertical x-axis against gravity.

As shown in fig. 3, the guide rail 62 is shown in cross-hatching, and the head gantry 42 is omitted for visibility reasons. As the printed 3D part 50 and skeleton 54 grow along the z-axis, the guidance of platen 36 in the direction of arrow 86 causes platen 36 to move through chamber 34 toward port 58. The port 58 is desirably sized to allow the platen 36 to pass through the port 58 without contacting the chamber wall 48. Specifically, the port 58 is desirably parallel (or substantially parallel) to the platen 36 (i.e., both extend in the x-y plane), the port 58 having a dimension slightly larger than the cross-sectional area of the platen 36. This allows the platen 36 (and the grown 3D part 50 and the skeleton 54) to pass through the port 58 without interference, while also desirably reducing heat loss through the port 58.

As the printed layers of 3D part 50, support structure 52, and skeleton 54 move through chamber 34 in the direction of arrow 86 toward port 58, the temperature of chamber 34 gradually cools them from their respective extrusion temperatures to the temperature in chamber 34. As mentioned above, this reduces the risk of twisting and curling. The stage assembly 38 desirably guides the platen 36 at a rate slow enough that the printed layer cools to the temperature of the chamber 34 and resides in the chamber 34 for a period of time sufficient to substantially relieve the cooling stress before reaching the port 58. This allows the printed layers to be relaxed sufficiently so that when they reach the temperature gradient at port 58, the temperature drop at the temperature gradient does not cause any substantial distortion or curling.

Fig. 4A and 4B illustrate 3D part 50, support structure 52, skeleton 54, and platen 36 during a printing operation. 3D component 50 includes an inner structure 50a and an outer surface 50b, where inner frame 50a functions in the same manner as skeleton 54 for laterally supporting outer surface 50b of 3D component 50. In alternative embodiments, depending on the geometry of 3D part 50, internal structure 50a may be omitted or may be printed out of a support material (e.g., a dissolvable support material) that can be subsequently removed from 3D part 50. In embodiments where interior structure 50a is made from a dissolvable support material print, interior frame 50a is desirably porous and/or sparse to increase the flow of dissolving fluid (e.g., aqueous alkaline solution) through the interior region of 3D part 50. This can increase the dissolution rate of the inner structure 50 a.

In the example shown, carcass 54 includes strip portions 88 and a conveyor base 90. Further details of this strap-based structural arrangement for the skeleton 54 will be discussed below. In short, the strap portion 88 is connected to the outer surface 50b of the 3D part 50 at a small contact point to support the 3D part 50 against sagging due to gravity. The small contact points allow the strip portion 88 to be easily separated or otherwise removed from the 3D part 50 after the printing operation is completed. The conveyor base 90 is a planar sheet that supports the band portion 88, providing a smooth surface that can ride on the guide rails 62 and slide on the guide rails 62 as the platen 36 is guided along the z-axis.

As further shown in fig. 4A and 4B, the support structure 52 is desirably printed on the receiving surface 36a to encompass at least the footprint area of the 3D part 50 and the skeleton 54 (i.e., the cross-sectional area of the 3D part 50 and the skeleton 54 in the x-y plane). In the example shown, the support structure 52 covers only about 40% of the bottom surface of the platen 36. However, for 3D parts and skeletons having larger geometries in the x-y plane, the entire surface of platen 36 may be used, allowing the 3D part to have a cross-sectional area up to approximately the cross-sectional area of platen 36 where platen 36 is printed. Furthermore, the length of the 3D part may be limited only by the length of the platen gantry 38. Thus, system 30 is suitable for printing long 3D parts having a variety of different cross-sectional geometries, such as wings, manifolds, fuselages, and the like.

As shown in fig. 4B, the platen 36 includes a base notch 91, the notch 91 being configured to align with the top surface of the guide rail 62. This structural arrangement allows the conveyor base 90 of the support structure 52 and the backbone 54 to be printed in alignment with the notch 91. This allows the support structure 52 and the skeleton 54 to rest on the guide rails 62 and slide on the guide rails 62 while guiding the platen 36 in the direction of arrow 86.

As shown in fig. 5, platen stage 38 continuously guides platen 36 in the direction of arrow 86, successive layers of 3D part 50 and skeleton 54 pass through the thermal gradient at port 58 and move out of chamber 34. As described above, the printed layer is desirably cooled to the temperature of the chamber 34 before reaching the port 58 to reduce the risk of distortion and curling. The printed layers may then cool to ambient temperature (e.g., room temperature) outside of chamber 34 while passing through port 58.

The printing operation may continue until the last layer of 3D part 50 is printed and/or when platen 36 is fully guided to the end of platen gantry 38. As can be appreciated, allowing the platen 36 to move outside of the chamber 34 increases the length of the 3D part that can be printed by the system 30 as compared to additive manufacturing systems having closed chambers.

After the printing operation is complete, the printed 3D part 50, support structure 52, skeleton 54, and platen 36 may be removed from system 30 (e.g., by detaching lower platen 36 from platen gantry 38). Platen 36 may then be removed from support structure 52, and support structure 52 may be removed from 3D part 50 and skeleton 54 (e.g., by dissolving support structure 52). The skeleton 54 may then be separated from the 3D part 50 or otherwise removed from the 3D part 50.

Although system 30 is particularly suited for printing 3D parts that are long along the z-axis (i.e., 3D part 50), system 30 may also print 3D parts that are shorter along the z-axis. In the case where 3D part 50 is short along the z-axis such that the viscosity of support structure 52 is sufficient to support the 3D part in a cantilevered manner without substantial sag, skeleton 54 may be omitted. However, as can be appreciated, as the length of the 3D part grows along the z-axis, the support structure 52 by itself is insufficient to prevent the distal printed layer of the 3D part from sagging under the force of gravity. In this case, one or more skeletons (e.g., skeleton 54) may be printed with the 3D part to laterally support the 3D part.

Fig. 6-9 illustrate a system 230 that is a second exemplary additive manufacturing system having a platen actuator and associated drive mechanism. As shown in fig. 6, system 230 may operate in a similar manner as system 30 (shown in fig. 2-5), with reference numerals increased by "200" for the respective features. In this embodiment, platen 36 and platen stage 38 of system 30 are replaced by a platen actuator 292 and drive mechanism 294.

Actuator 292 is a removable print substrate having a platen portion 296, a platform portion 298, and a stiffening arm 300 (best shown in fig. 8B). The platen portion 296 includes a receiving surface 296a for receiving the printed support structure 252 in a similar manner as the receiving surface 36a of the platen 36. The platform portion 298 includes edge segments 302 and a center segment 304, wherein the edge segments 302 are offset from each other along the y-axis. The platen portion 296 is integrally formed with the platform portion 298 at the central section 304 or is otherwise connected to the platform portion 298 and does not extend transversely to the edge section 302. In this manner, the platen portion 296 extends parallel to the x-y plane and at right angles to the platform portion 298 extending in the y-z plane. The reinforcement arm 300 is an optional component that structurally reinforces the pressure plate portion 296.

Actuator 292 may be fabricated from one or more polymeric and/or metallic materials. For example, actuators 292 may be molded (e.g., injection molded) or printed from a polymer material using an additive manufacturing system to provide a rigid piece capable of supporting the printed layers of 3D part 250, support structure 252, and skeleton 254. In an alternative embodiment, the platform portion 298 may be a web or mesh based film to which the platen portion 296 is secured.

As shown in fig. 6 and 7, the drive mechanism 294 is a wheel-based drive mechanism that includes a guide track 308, a motor 310, and two pairs of drive wheels 306, wherein, in fig. 7, the guide track 308 is shown in cross-hatching (and the head stage 242 is omitted) for ease of viewing. Prior to a printing operation, the platform portion 298 of the actuator 292 may be inserted between the pair of drive wheels 306. The platform 298 may also include one or more alignment tabs 312 (best shown in fig. 8B) to align and slidably couple the actuator 292 to the guide track 308.

The guide track 308 acts as a linear support along the horizontal z-axis in a similar manner to the guide track 62 (shown in fig. 2, 3 and 5). However, the guide rails 308 are significantly shorter in length than the guide rails 62, thereby reducing the size of the system 10 on the table 232. For example, the guide track 308 may be held entirely within the cavity 234.

During operation, the printhead 240 initially prints one or more layers of the support structure 252 on the receiving plane 296a to provide an adhesive substrate for subsequent printing. This maintains good adhesion between the various layers of 3D part 250 and receiving surface 296 a. However, as best shown in fig. 8A and 8B, the multiple layers of support structure 252 also include an edge segment 314 corresponding to edge segment 302 of actuator 292 and an alignment tab 316 corresponding to alignment tab 312 of actuator 292 (as shown in fig. 8B).

After each layer of support structure 252 is printed, drive mechanism 294 may guide actuator 292 in increments of a single layer in the direction of arrow 286 along the z-axis. Specifically, as shown in fig. 8A, each pair of drive wheels 306 may engage opposing surfaces of each of the edge segments 302. The drive wheel 306 is operated by a motor 310 that rotates the drive wheel 306 to guide the actuator 292 along the z-axis in the direction of arrow 286.

In alternative embodiments, drive mechanism 294 may be replaced with a plurality of different drive mechanisms to engage and move actuator 292, support structure 252, and frame 254 in the same manner. For example, the drive wheel 306 may be replaced with the following structure: cogs, textured wheels, pointed wheels, textured and/or adhesive belts, etc., to engage one side of each edge segment 302, both sides of each edge segment 302, or a combination thereof.

After support structure 252 is printed, printhead 240 may then print the multiple layers of 3D part 250, as well as skeleton 254, and optionally any additional multiple layers of support structure 252. As further shown in fig. 8A and 8B, the delivery base 288 of the skeleton 254 is printed to include edge segments 318 corresponding to the edge segments 302 and 314, and alignment tabs 320 corresponding to the alignment tabs 312 and 316. In alternative embodiments, the alignment tabs 312, 316, and/or 320 may be omitted. In these embodiments, the system 230 may include other suitable features (e.g., alignment pins) to maintain alignment in the x-y plane.

As the drive wheel 306 continues to guide the actuator 292, the alignment tab 316 of the support structure 252, and the alignment tab 320 of the skeletal frame 254 in the direction of arrow 286, eventually reaching the guide track 308 and slidingly engaging the guide track 308 to maintain proper alignment in the x-y plane. Further, as shown by arrow 322 in fig. 8A, the drive wheel 306 eventually passes over the edge segment 302 of the actuator 292 and engages the edge segments 314 and 318 to continuously guide the support structure 250 and the frame 254 in the direction of arrow 286. In some embodiments, the system 230 may include one or more sensors (not shown) to provide feedback to the controller 280, thereby maintaining proper guidance of the skeleton 250. For example, the system 230 may include one or more optical sensors to measure displacement of the skeleton 250 along the z-axis, which may transmit signals to the controller 280 to provide precise guidance of the skeleton 250.

As can be appreciated, because drive wheels 306 engage skeletal frame 254 on both sides of edge segment 318 of skeletal frame 254, opposing drive wheels 306 may need to be adjusted along the y-axis to compensate for the size of 3D component 250. For example, if the 3D part 250 is very wide along the y-axis, the opposing pair of drive wheels 306 may need to be further separated along the y-axis (as shown by separation line 321 in fig. 8A) to accommodate the wider support structure 252 and backbone 254. Alternatively, if the 3-D part 250 is very narrow along the y-axis, the opposing pair of drive wheels 306 may need to be moved closer together along the y-axis to reduce the width of the support structure 252 and the skeleton 254. This reduces the size of the requirements for the support structure 252 and the backbone 254. However, in one embodiment, the drive wheels 306 may maintain a spacing distance along the y-axis that accommodates the widest size that can be printed by the system 230. In this embodiment, the support structure 252 and the skeleton 254 may be printed at a width that reaches the drive wheel 306.

Alternatively, as shown in FIG. 8c, system 230 may include an optional drive mechanism, such as drive mechanism 294a, that engages only the bottom surfaces of support structure 252, frame 254, and actuator 292. As shown, drive mechanism 294a includes rollers 306a and drive belt 306b, wherein drive belt 306b engages support structure 252, frame 254, and the bottom surface of actuator 292. This engagement of the bottom surface allows for the use of drive mechanism 294a regardless of the dimensions of 3D component 250, support structure 252, and skeleton 254.

Drive belt 306b may engage actuator 292, support structure 252, and frame 254 with a variety of different features, such as a textured and/or tacky belt surface. This allows drive belt 306b to frictionally, mechanically, and/or adhesively grip the underside of actuator 292, support structure 252, and frame 254, thereby guiding or otherwise moving them in the direction of arrow 286. The engagement between drive belt 306b and actuator 292, support structure 252, and frame 254 may be based on the weight of actuator 292, support structure 252, and frame 254, holding them against drive belt 306 b. Additionally, drive mechanism 230 may include additional components to help maintain the engagement, such as a magnetic coupling between actuator 292 and drive mechanism 294 a. As will be further appreciated, although drive mechanism 294a is shown with drive belt 306b, drive mechanism 294a may alternatively incorporate different features (e.g., drive wheels) to engage actuator 292, support structure 252, and the bottom surface of frame 254.

As shown in fig. 9, as drive mechanism 294 continues to guide skeleton 254 in the direction of arrow 286, successive layers of 3D component 250 and skeleton 254 pass through the thermal gradient at port 258 and move out of chamber 234. In this embodiment, the table or surface 232 desirably steps up outside of the chamber wall 248 to receive the alignment tabs 312, 316, and 318, allowing them to slide across the table 232 during indexing. Further, the stepped up portion of the table 232 may be treated or polished, may include a low friction material (e.g., polytetrafluoroethylene), and/or may include a gas jet to form a gas cushion, thereby reducing sliding friction with the alignment tabs 312, 316, and 318. Alternatively, in embodiments where the alignment tabs 312, 316, and 318 are omitted, the stepped up portion of the table 232 may be aligned with or slightly below the height of the guide track 308 to receive the transfer base 288 of the skeleton 254.

The printed layer may then cool to ambient temperature (e.g., room temperature) outside of chamber 234 while passing through port 258. The printing operation may continue until the last layer of the 3D part 250 is printed. As can be appreciated, by printing the support structure 252 and the framework 254 with edge segments 314 and 318 that can be engaged by the drive mechanism 294, the system 230 is effectively grown on its own transport mechanism. Using a conveyor-based skeleton in this manner allows the guide track 308 to be relatively short and even remain inside the chamber wall 248. This reduces the overall size of system 230 and effectively allows 3D part 250 to be printed at an infinite length along the z-axis.

Fig. 10-14 show a system 430 with a wedge actuator and associated drive mechanism as a third exemplary additive manufacturing system. As shown in fig. 10, system 430 operates in a similar manner to system 230 (shown in fig. 6-9), wherein the reference numerals for the various features corresponding to system 30 (shown in fig. 2-5) are increased by "400" and the reference numerals for the various features corresponding to system 230 are increased by "200". In this embodiment, the platen actuator 292 of the system 230 is replaced by a wedge actuator 492.

Actuator 492 is a print substrate similar to actuator 292 and includes a wedge portion 496 (instead of a platen portion 296) and a platform portion 498 and may be made of metal and/or a polymer material. The wedge 496 has a ramped geometry including a receiving surface 496a for receiving a printed layer of the support structure 452. The platform 498 includes an edge segment 502 and a center segment 504 and functions in the same manner as the platform 298 of the actuator 292. The wedge 496 is integrally formed with the platform 498 at the center segment 504 or otherwise connected to the platform 498 and does not extend laterally to the edge segment 502. In this manner, the receiving surface 496a extends parallel to the x-y plane and at right angles to the platform 498 extending in the y-z plane.

Actuator 292 (shown in fig. 6-9) and actuator 492 illustrate exemplary actuators of the present disclosure. Each actuator of the present disclosure may include a platform portion and a receiving surface, wherein the particular geometry used to structurally reinforce the receiving surface relative to the platform portion may vary. In embodiments where the receiving surface is small, additional structural reinforcement is not necessary, and the actuators may have an "L" or block-type geometry. As the size of the receiving surface increases, one or more structural stiffeners (e.g., the ramped geometry of the stiffener arms 300 and wedges 496) may be desirable to prevent the receiving surface from flexing or wobbling during printing operations.

As shown in fig. 10 and 11, the drive mechanism 494 is a wheel-based drive mechanism that functions in the same manner as the drive mechanism 294 and includes a guide rail 508, a motor 510, and two pairs of drive wheels 506, wherein, in fig. 7, the guide rail 308 is shown in cross-hatching (and the head gantry 242 is omitted) for ease of viewing. Prior to a printing operation, the platform 498 of the initiator 492 may be inserted between the pairs of drive wheels 506. The printhead 440 may then initially print one or more layers of the support structure 452 on the receiving surface 496a, wherein the angled geometry of the wedge 496 reinforces the receiving surface 496 a.

However, as shown in fig. 12, receiving surface 496a of wedge 496 has a small cross-sectional area compared to receiving surfaces 36a and 296a and is also smaller than the footprint area of the combination of 3D component 450 and skeleton 454. In this manner, in this embodiment, the support structures 452 may be grown with increasing cross-sectional area in the x-y plane. This may be accomplished by printing successive layers of the support structure 452 with increasing cross-sectional area of the support structure 452 in the x-y plane. For example, successive layers of support structure 452 may be printed at the following angles without the need for support of the previous layer: the angle of the increasing dimension in any direction from the z-axis (e.g., angle 526) may be up to about 45 °.

Support structure 452 may be grown with at least an increasing cross-sectional area until it encompasses the footprint of 3D part 450 and skeleton 454 (i.e., the cross-sectional area of 3D part 450 and skeleton 454 in the x-y build plane). Additionally, as best shown in fig. 13A and 13B, the layers of support structure 452 may be printed to include an edge segment 514 corresponding to edge segment 502 of initiator 492, and an alignment tab 516 corresponding to alignment tab 512 of initiator 492 (as shown in fig. 13B).

After each layer of support structure 452 is printed, drive mechanism 494 may index actuator 492 in the direction of arrow 286 along the z-axis in increments of a single layer, in the same manner as described above for actuator 292 and drive mechanism 294. Thus, the last printed layer of support structure 452 serves as a print substrate receiving surface for 3D part 450 and skeleton 454. The print head 440 may then print multiple layers of the 3D part 450 and skeleton 454, and optionally any additional multiple layers of the support structure 452. As further shown in fig. 13A and 13B, the transport base 488 of the skeleton 454 is printed to include an edge segment 518 corresponding to the edge segments 502 and 514, and an alignment tab 520 corresponding to the alignment tabs 512 and 516.

As the drive wheel 506 continues to guide the trigger 492 in the direction of arrow 486, the alignment tab 516 of the support structure 452 and the alignment tab 520 of the skeleton 454 eventually reach the guide rail 508 and slidingly couple with the guide rail 508 to maintain proper alignment in the x-y plane. Further, as indicated by arrow 522 in fig. 13A, the drive wheel 506 eventually passes over the edge segment 502 of the actuator 492 and engages the edge segments 514 and 518 to continuously guide the support structure 450 and the frame 454 in the direction of arrow 486.

As shown in fig. 14, as the drive mechanism 494 continues to guide the skeleton 454 in the direction of arrow 486, successive layers of the 3D component 450 and skeleton 454 pass through the thermal gradient at the port 458 and move out of the chamber 434. The printed layer may then cool to an ambient temperature (e.g., room temperature) outside of chamber 434 while passing through port 458.

The printing operation may continue until the last layer of 3D part 450 is printed, or as described below, additional 3D parts may be printed using skeleton 454, where portions of skeleton 454 may serve as a print substrate receiving surface for the additional 3D parts. The use of actuator 492 achieves the same advantages as the use of actuator 292 by reducing the overall size of system 430 and allowing 3D part 450 to be printed at an infinite length along the z-axis. In addition, wedges 494 reduce the size and weight of actuators 492 relative to actuators 292 and allow the last layer of support structure 452 to serve as a print substrate receiving surface for 3D part 450 and skeleton 454.

Fig. 14A-14D illustrate an alternative system 430 that includes one or more wedge actuators secured to a rotating band mechanism. As shown in fig. 14A, in this embodiment, the platform 498 of each actuator may be omitted, resulting in only the wedge 496 being secured to the strap 508 a. Optionally, if desired, each actuator may include a platform 498 secured to the band 508 a. The belt 508a may thus be rotated in the direction of arrow 508b by a drive wheel 506a and/or an idler wheel 506a, one or more of which drive wheel 506a and/or idler wheel 506a may be driven by a motor 510 a.

The belt 508a is desirably rigid enough to prevent vibrational movement during printing operations, while also being flexible enough to rotate about the wheel 506 a. Suitable materials for the strap 508a include fiber reinforced (reinforced) rubber (e.g., steel fibers and/or aramid fibers), plastic (e.g., polyamide and/or polyetherimide), thin metal sheets (e.g., stainless steel and/or aluminum), and the like. Each wedge 496 may be secured to the strap 508a using a suitable mechanism such as a mechanical interlock, an adhesive strap layer, combinations thereof, and the like. In some embodiments, each wedge 496 may be removably attached to the strap 508a (e.g., via one or more clamps), thereby allowing each wedge 496 to be repositioned along the strap 508a as desired by a user. Wedge-shaped materials-plastics or metals.

As further shown in fig. 14A, each wedge 496 may receive a printed 3D part 450, support structure 452, and skeleton 454 in the same manner as described above. The length of 3D part 450 is not limited by the length of band 508a along the z-axis because wedge 496 is preferably removable from band 508 a. For example, as 3D part 450 is being built and moved along the z-axis, wedge 496 can be removed from the part before reaching the end point of the band. In this case, a table or other support surface may be positioned to support the leading edge of 3D part 450 as the leading edge of 3D part 450 extends beyond the length of belt 508 a. In contrast to the previous embodiments, as the length of 3D component 450 and skeleton 454 lengthens, band 508a may serve as a lateral support for skeleton 454, thereby eliminating any potential sliding friction that may otherwise occur between skeleton 454 and any underlying surface (e.g., the surface of table 432).

As shown in fig. 14B, each wedge 496 is desirably secured to a strap 508 a. In contrast, if desired, the tail portion 498c of each wedge 496 is desirably not secured to the strap 508a, but may include a gripping or adhesive surface, or a removable clamp, to reduce movement between the wedge 496 and the strap 508 a. This arrangement allows each wedge 496 to be flipped about the wheel 506a as the tape 508a rotates such that the receiving surface 496a extends parallel to the x-y plane at a location closer to the printhead 440 than the tape 508 a. For example, the receiving surface 496a can extend closer to the printhead 440 along the z-axis than the tape 508a (and/or the wheel 506a) by an exit distance 496 d. Suitable distances along the z-axis for the lead-out distance 496d range from about 5 millimeters to about 50 millimeters. This prevents the tape 508a and wheel 506a from interfering with the printhead 440 during printing operations and/or allows the wedge 496 to tumble around the wheel 506 a.

Between printing operations, the tape 508a may be rotated to position a given wedge 496 for receiving printed components and support material from the printhead 440 (such as shown in fig. 14A and 14B). As a given wedge 496 flips around the wheel 506a in the chamber 434, the printhead 440 desirably is moved away from the ribbon 508a (e.g., raised along the x-axis) to prevent the wedge 496 from colliding with the printhead 440. When the wedge 496 is positioned to receive the printed components and support material from the printhead 440, the printhead 440 may be moved back and may be subjected to one or more calibration procedures using the positioned wedge 496. As can be appreciated, the embodiment shown in fig. 14A and 14B allows for printing multiple 3D parts 450 with continuously rotating tape, where each wedge 496 and/or printed 3D part 450 (and associated support structure 452 and skeleton 454) may be removed (e.g., by a user or robot) before the tape 508a reaches its endpoint along the z-axis. Similarly, other wedges 496 may be positioned for the next ordered part to be built. By adding and removing wedges 496, the system 430 can be adapted to the size and number of components being printed.

In another embodiment, as shown in FIG. 14C, the tape 508a may extend into one or more post-printing processing stations, such as processing stations 445a-445 d. For example, the processing stations 445a-445d may independently be automated support removal stations, automated surface treatment stations, grinding or other automated subtractive manufacturing stations, automated painting (e.g., painting) stations, automated plating stations, or the like.

Examples of suitable automated support removal stations include the removal station disclosed in Swanson et al, U.S. patent No.8,459,280. For example, as shown in fig. 14D, the belt 508a may be dipped in a removal solution or liquid at station 445a for removing the support structure 452, and then raised back out of the solution or liquid for drying. In some cases, it may be preferable to have 3D component 450 and/or backbone 454 remain at least partially connected to wedge 496 so that 3D component 450 remains movable with rotation of band 508a after support structure 452 is removed (e.g., with a break feature).

Examples of suitable surface treatment stations include automated surface treatment systems such as those disclosed in the following documents: U.S. Pat. No.8,123,999 to Priedeman et al; U.S. patent nos. 8,075,300 to Zinniel; and U.S. publication No.2008/0169585 to Zinniel. These systems may produce a smooth, polished, and/or polished surface for each 3D part 450 located at an exposed location.

As can be appreciated, because the belt 508a rotates in the direction of arrow 508b, the printed 3D part 450/support structure 452/skeleton 454 may be moved in series to each processing station 445a-445D in an assembly line fashion. In some stations, such as in a surface treatment station, a grinding or other automated subtractive manufacturing station, and/or a painting station, each 3D part 450 (with or without support structure 452) is preferably processed between multiple printing operations of successive multiple 3D parts 450. This prevents the guide tape 508a from adversely affecting the post-printing process during printing.

In contrast, with other stations, such as with a support removal station, 3D part 450/support structure 452/skeleton 454 may be directed into the support removal station in subsequent printing operations, if desired, because the support removal solution or liquid typically does not adversely affect the part material, regardless of the length of residence time in the support removal station. However, in embodiments where the part material may be adversely affected by the support removal solution or liquid over an extended period of time, it may be preferable to limit the residence time in the support removal station.

Exemplary arrangements of the processing stations 445a-445d may include a grinding or other automated subtractive manufacturing station 445a, a surface treatment station 445b, a painting station 445c, and a support removal station 445 d. This arrangement is advantageous in the following cases: the surface of 3D part 450 that is in contact with support structure 452 does not require surface treatment, grinding, or painting (e.g., for producing dental implants). A variety of post-printing processing stations and arrangements of such stations may also be used.

Fig. 14E-14G illustrate another alternative embodiment that incorporates an auger-based viscous pump for a print head 440, the print head 440 configured to print from a granular component and/or a support material (e.g., a powder-based material). For example, as shown in fig. 14E, system 430 (and systems 30 and 230) may include a print head 440a that is an auger-based viscous pump configured to receive the particulate component or support material from hopper 444a via conduit 470 a. Conduit 470a is desirably a short feed path between hopper 444a and printhead 440a to transport particulate material.

Examples of suitable viscous pumps for printhead 440a include pumps configured to receive particulate material disclosed in the following patents: U.S. patent nos. 5,312,224 and 5,764,521 to Batchelder et al, and 7,891,964 to Skubic et al. Other examples of suitable viscous pumps for printhead 440a include the pumps disclosed in the following patent applications: U.S. patent application No.13/525,793 to Bosveld et al, which is incorporated herein by reference to the extent it does not conflict with the present disclosure. The print head 440a may operate in accordance with any of the above-disclosed embodiments in a manner similar to the print heads 40, 240, and/or 440 used to print the 3D part 450, the support structure 452, the skeleton 454.

Additionally, the hopper 444a may receive particulate material from one or more supply containers 441, for example, using a tool changer 443a as discussed in U.S. patent application No.13/525,793 to Bosveld et al. This allows the hopper 444a to be refilled with the same or a different material when necessary or desired.

As shown in fig. 14F, the printhead 440a may include a housing portion 447a, a mixing channel 447b, a rotatable auger 447c, and a nozzle 447d, wherein the particulate material is conveyed to the mixing channel 447 b. In the mixing channel 447b, the particulate material is melted and sheared into an extrudable state with rotation of the auger 447c and may be extruded out of the nozzle 447 d.

As shown in fig. 14G, the system 430 (and systems 30 and 230) may also include a head tool changer 443b configured to interchangeably engage a plurality of auger-based viscous pumps, such as printheads 440a-440c, with a head carriage (not shown) corresponding to the head carriage 42. In this embodiment, as shown, each print head 440a-440c may receive particulate components or support material from one or more hoppers 444 a-444 c, respectively, via conduits 470 a-470 c. Each hopper 444a to 444c is also filled with granules from a plurality of supply containers 441 using the tool changer 443a as described above.

Each print head 440a-440c may operate in accordance with any of the above-disclosed embodiments in a manner similar to print heads 40, 240, and/or 440 used to print 3D part 450, support structure 452, and/or skeleton 454. However, in this embodiment, each printhead 440a-440c may be dedicated to a particular component or support material, and/or may be a different size or configuration, if desired.

Vertical printing

Fig. 15 and 16 illustrate a system 630 as an example additive manufacturing system for vertically printing tall 3D parts with an expanded print volume of the present disclosure, such as the additive manufacturing system described above for the 3D part 10 (shown in fig. 1A). As shown in fig. 15, system 630 may operate in a similar manner to system 430 (shown in fig. 10-14), wherein the reference label for each feature corresponding to system 30 (shown in fig. 2-5) is increased by "600", the reference label for each feature corresponding to system 230 (shown in fig. 6-9) is increased by "400", and the reference label for each feature corresponding to system 430 is increased by "200".

In the illustrated embodiment, the system 630 may be supported on legs or other suitable extensions 730 above a floor or other suitable surface 632. The port 658 extends through the bottom chamber wall 648 and is substantially parallel to the x-y plane. Accordingly, system 630 is configured to print 3D part 650, support structure 652, and skeleton 654 along a print z-axis, which is a vertical axis, where actuator 692 may be directed downward along the z-axis in the direction of arrow 686.

As drive mechanism 694 continues to guide trigger 692, support structure 652, and backbone 654 in the direction of arrow 686, successive layers of 3D part 650, support structure 652, and backbone 654 pass through the thermal gradient at port 658 and move out of chamber 634. The printed layer may then cool to ambient temperature (e.g., room temperature) outside of the chamber 634 while passing through the port 658. The printing operation may continue until the last layer of 3D part 650 is printed, or/and when actuator 692 is fully directed to surface 632. As can be appreciated, allowing the 3D part 650 to move downward out of the chamber 634 increases the height that can be printed by the system 630 compared to additive manufacturing systems having closed chambers.

As discussed above with respect to armatures 18a and 18b (as shown in fig. 1A), armatures 654 may be printed to support lateral sides of 3D part 650. This allows the drive mechanism 694 to guide the backbone 654 downward, as shown in fig. 16. In addition, the backbone 654 may reduce or prevent wobble that may occur while printing the 3D part 650, thereby substantially maintaining proper alignment between the 3D part 650 and the print head 640.

Although described with wedge-shaped actuators 692 and wheel-based drive mechanisms 694, system 630 can alternatively be used with a variety of different print substrate and drive mechanisms, such as platen and platen stage (e.g., platen 36 and platen stage 38) and platen actuator (e.g., actuator 292), which can be used in the same manner as described above for systems 30 and 230. In these embodiments, the skeleton 654 may be used continuously to reduce wobble by laterally supporting the 3D part 650.

Multiple chambers

Embodiments of additive manufacturing systems for use in the present disclosure as described above may be referred to as a single chamber system that provides two temperature zones (i.e., ambient temperatures inside and outside the chamber). Fig. 17 shows an alternative system 830 having multiple chambers to provide four temperature zones. As shown in fig. 17, system 830 may operate in a manner similar to that of system 430 (as shown in fig. 10-14), wherein the reference label for each feature corresponding to system 30 (as shown in fig. 2-5) is increased by "800", the reference label for each feature corresponding to system 230 (as shown in fig. 6-9) is increased by "600", the reference label for each feature corresponding to system 430 is increased by "400", and the reference label for each feature corresponding to system 630 is increased by "200".

System 830 includes chambers 834a, 834b, and 834c having chamber walls 848a, 848b, and 848c, heating mechanisms 856a, 856b, and 856c, and ports 858a, 858b, and 858c, respectively. The multi-chamber arrangement provides multiple temperature gradients at ports 858a, 858b, and 858 c. For example, the heating mechanism 856a may maintain the chamber 834a at a first temperature, the heating mechanism 856b may maintain the chamber 834b at a second temperature that is lower than the first temperature, and the heating mechanism 856c may maintain the chamber 834c at a third temperature that is lower than the second temperature and higher than an ambient temperature (e.g., room temperature).

This embodiment is particularly suitable for use with temperature and oxygen sensitive materials, such as polyamide materials (e.g., nylon-based materials), which oxidize when exposed to elevated temperatures in a heated environment, potentially making them brittle. As described above for the single chamber systems 30, 230, 430, and 630, the drive mechanism desirably directs the print substrate at a rate slow enough so that the printed layer resides in the chamber for a period of time sufficient to substantially relieve the cooling stress before reaching the port to ambient. This allows the printed layers to be relaxed enough so that when they reach the temperature gradient at the port, the temperature drop of the temperature gradient does not cause any substantial distortion or curling. However, this can result in oxidation of temperature/oxygen sensitive materials before reaching the ports.

Alternatively, as shown in fig. 17, the use of multiple chambers allows printed layers to pass from chamber 834a to chamber 834b via port 858a before completely relieving their cooling stress. The second temperature of chamber 834b is desirably high enough to allow the layer to gradually relax without twisting or curling, while also being low enough to reduce the rate of oxidation of the component material (or prevent oxidation altogether). The process may continue to chamber 834c (via port 858b) and continue to gradually relax the printed layer before reaching port 858 c.

The particular temperature maintained in chambers 834a, 834b, and 834c may vary based on the particular components and support materials used. In addition, the number of chambers (chambers 834a, 834b, and 834c may vary). A suitable number of chambers may range from 1 to 5. In addition, the dimensions of each chamber may be the same or different to accommodate cooling of different components and support materials. In these embodiments, the size of each cavity may be varied, such as with collapsible type walls 848a, 848b, and 848c, to further accommodate cooling of the different components and support materials. As can be appreciated, the use of multiple sequential chambers maintained at a stepped-down temperature increases the amount of material that can be printed by the additive manufacturing system of the present disclosure.

Framework

As described above, the skeletons of the present disclosure (e.g., skeletons 54, 254, 454, and 654) may provide a variety of functions during printing operations with an additive manufacturing system. For example, the skeleton may laterally support the printed 3D part during a horizontal printing operation to prevent the 3D part from sagging due to gravity. In addition, the skeleton may laterally support the printed 3D part during the vertical printing operation to prevent the 3D part from shaking. Further, during horizontal and vertical printing operations, the skeleton may include conveyor bases that may be guided by a drive mechanism of the additive manufacturing system, thereby allowing the 3D parts and skeleton to be guided out of the system without requiring long gantries. Additionally, as described below, the skeleton may function as a printing substrate receiving surface for printing a plurality of consecutive 3D parts.

Fig. 18A-18C and 19 illustrate exemplary skeletons that may be printed using an additive manufacturing system. However, the skeletons of the present disclosure are not limited to these particular embodiments and may optionally include a number of different geometries based on their particular purpose. However, the embodied skeleton as shown in fig. 18 and 19 is particularly suitable for use in printing 3D parts as follows: the 3D parts are long or tall along their printing axis relative to their cross-sectional dimension.

In the example shown in fig. 18A-18C and 19, the skeleton is printed with a thin-walled 3D part (e.g., a thin-walled panel). In some embodiments, with the printhead nozzles disclosed in concurrently filed U.S. patent application No.13/587,002, each layer of a thin-walled 3D component, support structure, and/or skeleton may be printed with a narrow perimeter path and a wider interior path. In addition, the 3D parts, support structures, and skeletons disclosed herein are printed using suction or drawing control techniques disclosed in concurrently filed U.S. patent application No.13/587,006.

For example, FIG. 18A shows a thin-walled 3D part 940 printed horizontally with a skeleton 942, which skeleton 942 may be implemented in the same manner as skeletons 54, 254, and 454 described above. In this example, 3D part 940 includes major outer surfaces 940a and 940b, and skeleton 942 includes strip portion 944 and conveyor substrate 946. The strap portions 944 support the outer surface 940b of the 3D component 940 via contact points 948 against gravity.

Contact points 948 are spaced along the z-axis (not shown) at the respective peaks of the strip 944, and each contact point may be a single drop of a component or support material that connects the outer surface 940b to the strip 944. In particular, the contact points 948 may be located at a tangent to the undulating pattern of the strip portions 944. The convergence of the contact points 948 allows the strap portions 944 to laterally support the 3D component 940 against gravity (i.e., prevent sagging), while also allowing the strap portions 944 to be easily removed from the 3D component 940 without undue effort.

In embodiments where the droplets at contact point 948 are from the part material, the droplets may serve as break-off locations due to their relatively weak adhesion. Alternatively, in embodiments where the droplet at contact point 948 is from a dissolvable support material, the droplet is also dissolved away to separate the strip portion 944 from the 3D part 940. The conveyor substrate 946 may be a flat sheet that supports the band portions 944, thereby providing a smooth surface that may rest on and slide over the guide rails and/or other surfaces, and as described above, may help guide the spine 942 and 3D components 940.

Alternatively, as shown in fig. 8B, a single skeleton 942 may laterally support multiple adjacently printed components 940a and 940B. In this embodiment, 3D components 940a and 940b may be printed laterally adjacent to each other along the y-axis with a strip portion 944 stabilizing each of them.

In addition, as shown in fig. 18C, multiple skeletons 942a and 942b (with ribbon portions 944a and 944b) may be used to print multiple stacked 3D parts 940a and 940b, with the 3D parts 940a and 940b adjacent to each other along the x-axis. In this embodiment, a strip portion 944b (or multiple strip portions 944b) may be disposed between stacked 3D parts 940a and 940b to support them while printing along the horizontal z-axis to prevent sagging.

Fig. 19 shows a thin-walled 3D part 950 printed vertically with a skeleton 952, which skeleton 952 may perform in the same manner as skeleton 654 described above, or may be printed vertically in an additive manufacturing system with large enclosed chambers, such as the additive manufacturing systems commercially available under the trademarks "FDM" and "FORTUS 900 mc" from Stratasys Prairie, inc. In this example, 3D component 950 includes major outer surfaces 950a and 950b, and skeleton 952 includes only strip 954 (excluding the conveyor base), which strip 954 supports outer surface 950b of 3D component 940 with contact points 956 to prevent sloshing. Contact points 956 may function in the same manner as contact points 948 for supporting 3D part 950 during a printing operation, while also allowing skeleton 952 to be easily removed from 3D part 950 after the printing operation is complete. For example, the contact points 956 may be located at a tangent to the corrugation pattern of the strip portions 954.

However, as discussed above, in the vertical printing orientation, skeleton 952 acts as a lateral support to reduce or prevent 3D component 250 from wobbling during the printing operation. For example, when 3D component 950 and skeleton 952 are printed using system 630 (shown in fig. 15 and 16), skeleton 952 may laterally support 3D component 950 as platen 636 is directed down out of chamber 634. Alternatively, when printing in a large enclosed chamber, such as in additive manufacturing systems commercially sold under the trademarks "FDM" and "FORTUS 900 mc" from den Prairie, of MN, the skeleton 952 may laterally support the 3D part 950 as the platen is guided down the large enclosed chamber. In each of these cases, the skeleton 950 may reduce or prevent the 3D part 950 from wobbling, thereby substantially maintaining proper alignment between the 3D part 950 and the print head.

This applies in particular to 3D parts with the following aspect ratios: the aspect ratio of the height of the 3D part along the printing z-axis relative to its smallest cross-sectional area in the x-y plane (or a plane perpendicular to the printing axis) is about 5:1 or greater. Thus, a scaffold (e.g., scaffold 950) desirably has a cross-sectional area in the x-y plane (or a plane perpendicular to the printing axis) such that the combined cross-sectional area for each printed layer (of the 3D part and the scaffold) is less than 5: 1.

Further, the skeletons 942 and 952 may be printed with a single path width per layer. For example, each layer of the strip portion 944 of the scaffold 942 and the conveyor substrate 946 (shown in fig. 17) may each be printed with a single path width, and each layer of the strip portion 954 of the scaffold 952 (shown in fig. 18) may be printed with a single path width.

The corrugation pattern of the strip portions 944 and 954 allows: the printhead prints each layer at a substantially constant tip rate or speed without necessarily slowing down the angular vertices at the crests and troughs of the undulations. This, along with the single path width, can substantially reduce print time. Further, the corrugation pattern of the strip portions 944 and 954 allows for a substantially constant pull-out to be maintained, as disclosed in concurrently filed U.S. patent application No.13/587,006, which provides a good smooth path with reduced or no undulations or peaks.

The skeleton of the present disclosure is also suitable for printing a plurality of consecutive 3D parts in a consecutive manner, especially when used in combination with the additive manufacturing system and starter of the present disclosure. FIG. 20A shows 3D parts 958a, 958b, and 958c printed on support structures 960A, 960b, and 960c with a skeletal assembly 962 (having skeletal sections 962a, 962b, and 962c) and an actuator 964, respectively, while being guided in the direction of arrow 966. The strip-based portions of 3D part 958a, support structure 960a, and skeleton segment 962a may be printed on actuator 964 in the same manner as described above for 3D part 450, support structure 452, skeleton 454, and actuators 492 (shown in fig. 6-9).

However, if multiple 3D parts are used in sequence for continuous printing, a system (e.g., system 430) may continuously print skeleton segment 962a to create wedge 968 with an increased cross-sectional area (in the same manner as described above for support structure 452). In this way, multiple layers of wedge 968 of skeleton segment 962a may be printed with an increased cross-sectional area until they surround at least the footprint area of 3D part 958b and skeleton segment 962 b. Thus, the last layer of wedge 968 serves as a print substrate receiving surface for support structure 960 b. At this point, support structure 960b, 3D part 958b, and skeleton section 962b may be printed, with support structure 960b disposed between skeleton section 962a and 3D part 958 b. Printing support structure 960b between wedge 968 and 3D part 958b allows 3D part 958b to subsequently detach from skeleton 962b (e.g., by dissolving support structure 960b) and may reduce the curling effect on 3D part 958 b.

The same technique may then be repeated to print the wedge 970 of the skeleton segment 962b, and then to print the support structure 960c, the 3D part 958c, and the skeleton segment 962 b. Because the system of the present disclosure has a heating chamber that is ported, the process can continue to continue printing successive 3D parts as long as desired. Each of the skeletal wedges (e.g., wedges 968 and 970) may have different dimensions corresponding to the footprint area of their respective 3D component, with each wedge defining a planar receiving surface in the x-y plane to begin subsequent printing. Thus, each printed 3D part may have different dimensions and geometries.

In the example shown, the wedges 968 and 970 are printed as part of the skeleton segments 962a and 962 b. In alternative embodiments, wedges 968 and 970 may be printed as part of support structures 960b and 960c in the same manner as support structure 960 a. In these embodiments, multiple layers of support structures 960b and 960c may be printed with increased cross-sectional area, as described above for support structure 452 (as best shown in fig. 12 above).

Furthermore, as shown in fig. 20B, support structure 960B may cover the entire footprint area of 3D part 958B and skeleton section 962B, thereby providing an edge section for support structure 960B. Similarly, support structure 960c may cover the entire footprint area of 3D part 958c and skeleton section 962c to provide edge sections for support structure 960 c. In this embodiment, skeletal segments 962a, 962b, and 962c may completely separate the plurality of skeletons, which are separated by support structures 960b and 960 c.

The 3D parts may be printed using this continuous technique by providing a tool path and associated printing instructions to an additive manufacturing system for each 3D part, support mechanism, and skeleton. In one embodiment, a host computer (e.g., host computer 484) may receive a digital representation that prints each 3D part in succession. The host computer may initially cut each digital 3D part and present the associated tool path. The host computer may also generate tool paths for the support structure and the skeleton, where the support structure and/or the skeleton have wedges to receive the continuous 3D part.

For example, the host computer may initially determine or otherwise identify the cross-sectional area of the print substrate receiving surface (e.g., the receiving surface for actuators 964), and the combined footprint area of 3D part 958a and skeleton 962 a. The host computer may then create a tool path for the layers of the support structure 960a, where the layers have an increased cross-sectional area starting at the location of the print substrate receiving surface until they encompass the combined footprint area of the 3D part 658a and the skeleton 962 a. The host computer may also cut the digital representation of 3D part 958a, giving the associated tool path for each layer, and generating the tool path for the layer of skeleton 962 a.

For 3D part 958b, the host computer may determine or otherwise identify the cross-sectional area of the last layer of skeleton 962a (before wedges 968) and the combined footprint area of 3D part 958b and skeleton 962 b. The host computer may then create tool paths for the layers of wedges 968, where the layers have increasing cross-sectional areas, starting at the location of the last layer of skeleton 962a until they encompass the combined footprint area of 3D part 658b and skeleton 962 b. The host computer may also cut the digital representation of 3D part 958b, give the associated tool path for each layer, generate a tool path for the layer of support structure 960b, and generate a tool path for the layer of skeleton 962 a. As described above, the tool path for the layers of wedge 968 may optionally be created as part of support structure 960 b.

The same process may then be repeated for wedge 970, 3D part 958c, support structure 960c, and skeleton 962 c; and for each subsequent 3D part afterwards. The host computer may then communicate the generated tool path and associated printing information to the additive manufacturing system to print the 3D part, the support structure, and the skeleton.

In an alternative embodiment, the host computer may receive the digital representation of the 3D part on an individual basis. For example, a host computer may receive, cut, and create tool paths for 3D parts 958a and 958b, support structures 960a and 960b, and skeleton segments 962a and 962 b. Because, in this example, no 3D part is scheduled to be printed after 3D part 958b, only a strip-based portion of skeleton segment 962b is needed (e.g., wedge 970 is not generated). The host computer may then communicate the generated tool paths and associated printing information to the additive manufacturing system to print the 3D parts 958a and 958b, the support structures 960a and 960b, and the skeleton segments 962a and 962b (without the wedge 970).

If the host computer then receives the digital representation of the 3D part 958c while the additive manufacturing system is printing, the host computer may cut and create tool paths for the 3D part 958c, the support structure 960c, the wedge 970 of the skeleton section 962b, and the skeleton section 962 c. The host computer may then communicate the generated tool path and associated print information to the additive manufacturing system to add to the end of the previous print order. This is achievable because the cross-sectional area of the last layer of the skeleton segment 962b is known, allowing the wedge 970 to be printed from the last layer of the skeleton segment 962b with an increased cross-sectional area.

This technique effectively allows the additive manufacturing system to continue printing multiple consecutive 3D parts along a single skeletal assembly, with each printed 3D part moving out of the chamber of the system via a port of the chamber (e.g., port 458). As can be appreciated, the use of actuators to print the substrate and associated drive mechanisms, in conjunction with this technique, effectively allows an unlimited number of 3D parts to be printed along the z-axis. After removal to the system, each printed 3D part may be separated from the skeletal assembly grown at the support structure connection of that 3D part, if desired, and then removed from its associated skeleton, as described above.

Examples of the invention

The disclosure is described in particular in the following examples, which are intended for illustrative purposes only, as many modifications and variations within the scope of the disclosure will be apparent to those skilled in the art.

Example 1

Horizontal printing operations were performed using additive manufacturing systems commercially available from Stratasys, inc. of Eden Prairie, minnesota under the trademarks "FDM" and "UPRINT" oriented such that the print z-axis was horizontal. A port may be cut into the base of the system and a platen gantry mounted to the system such that the platen gantry extends a few feet beyond the port. This system corresponds to system 30 (shown in fig. 2-5) having an extended platen gantry.

The system is operated to print a plurality of long 3D parts, including wings, manifolds, and thin-walled panels. During each printing operation, the chamber of the system is initially heated to an elevated operating temperature. This creates a thermal gradient between the elevated operating temperature inside the chamber and the ambient air (about 25 ℃) outside the chamber at the port.

The printhead initially prints multiple layers of support mechanism on a platen with a support material, which serves as an adhesive substrate for subsequent printing. The print head then prints the printed layer of the 3D part with a skeleton corresponding to skeleton 54, where both skeleton 54 and the 3D part are printed from the same part material. The skeleton has a strip portion and a conveyor substrate, where the strip portion is connected to the 3D part with a connection point drop of part material (as described above for skeleton 942 shown in fig. 18A).

After each layer is printed, the platen gantry guides the platen in increments of a single layer, which allows the 3D part and skeleton to grow horizontally. As it continues, the platen, support structure, 3D component, and skeleton eventually pass through the thermal gradient at the ports to extend out of the system. The base of the skeleton is suitably supported by the guide rails of the platen table, allowing the skeleton to slide across the guide rails during each guiding step.

When the printing operation is complete (after a few feet of 3D part and skeleton have been produced), the platen is then removed from the platen gantry and broken away from the support structure. The support structure is then removed and the skeleton can be easily detached from the 3D part. FIG. 21 is a photograph showing one of the 3D parts and associated skeleton being printed while still residing in the horizontally oriented system. The photograph was taken from the top opening, which was closed during the printing operation so that only a single port located behind the platen was open to the ambient. The photograph was taken prior to completion of the 3D part, showing only a small portion of the entire length of the 3D part and skeleton.

Upon visual inspection, each 3D part printed in this manner represents a very space-integrated type due to the heated environment in the chamber and the use of the associated skeleton. The heated environment in the chamber allows the 3D part and the scaffold to cool slowly to be sufficiently solidified until such time as they reach the thermal gradient at the ports to prevent warping or curling. In addition, long 3D parts may sag in other ways due to gravity during printing operations without the use of a skeleton. However, the skeleton stabilizes multiple layers of the 3D part, allowing long 3D parts to be printed along a horizontal printing axis.

Example 2

A horizontal printing operation was also performed using the system of example 1, in which the platen and platen gantry were replaced with wedge actuators and associated drive mechanisms. The system corresponds to system 430 (shown in fig. 10-14) and is operative to print a plurality of long 3D parts. During each printing operation, the chamber of the system is initially heated to an elevated operating temperature. This creates a thermal gradient between the elevated operating temperature inside the chamber and the ambient air (about 25 ℃) outside the chamber at the ports.

The print head initially prints multiple layers of the support mechanism on the receiving surface of the wedge portion of the actuator. As described above for the wedge actuator 492, the layers of the support structure are printed in an increasing cross-sectional area in the vertical x-y plane. Specifically, each successive layer is printed to provide the following angles: the increasing dimension makes an angle of about 45 deg. with the print axis (corresponding to angle 526 as shown in fig. 12). This is continued until the desired footprint cross-sectional area of the 3D part and skeleton is reached.

The print head then prints the print layer for a given 3D part using a skeleton corresponding to skeleton 454, both skeleton 454 and the 3D part being printed from the same part material. The skeleton has a strip portion and a conveyor substrate, where the strip portion is connected to the 3D part with a connection point drop of part material (as described above for skeleton 942 shown in fig. 18A).

After each layer is printed, the drive mechanism guides the wedge actuators in individual layer increments, which allows the 3D part and skeleton to grow horizontally. As this continues, the wedge actuators, support structures, 3D parts, and skeleton eventually pass through the thermal gradient at the ports to extend out of the system. At this point, the drive mechanism has passed the wedge actuator and has engaged the edge segment of the conveyor base of the carcass for the guiding step.

When the printing operation is completed, the backbone is removed from the drive mechanism. The wedge actuator is then separated from the support structure. The support structure is then dissolved and the scaffold can be easily detached from the 3D part. Each 3D part printed in this manner also exhibits a good spatial integration upon visual inspection due to the heated environment in the chamber and the use of the associated skeleton. Furthermore, the skeleton effectively acts as a guide conveyor for the drive mechanism, allowing the overall footprint area of the system to be reduced compared to that of the system in example 1, and also effectively allowing 3D parts to grow to unlimited lengths.

Example 3

A vertical printing operation was performed to produce a reduced size automotive hood using a skeleton (corresponding to 3D part 950 and skeleton 952 as shown in fig. 19) using additive manufacturing systems commercially available from Stratasys, inc, Eden Prairie, minnesota under the trademarks "FDM" and "FORTUS 900 mc". In this example, the system has a large enclosed chamber for printing a reduced size automobile hood and skeleton.

Each of the hood and backbone were printed from polycarbonate using the printhead nozzles disclosed in U.S. patent application No.13/587,002, respectively. The armature is attached to the rear side of the hood at a tangent location to the strap portion (as described above for armature 952) using attachment point drops of the component material. Each layer of the printed hood was printed with a wall thickness of 120 mils including two 20-mil wide peripheral paths followed by an 80-mil wide internal fill path. Each layer of the skeleton was printed as a single path wall of 40 mils.

The resulting hood and skeleton are shown in fig. 22 and 23, where the hood is 35 inches wide and 27 inches high. Upon visual inspection, the resulting hood exhibits a good spatial integrity due to the use of a skeleton that laterally supports the hood during printing operations. This prevents the upper portion of the hood from wobbling during the printing operation, thereby maintaining proper alignment between the layers of the printhead and the hood.

In addition, the additive manufacturing system having the above-described nozzle prints the entire hood and skeleton within 24 hours and 25 minutes, as described in co-pending U.S. patent application No.13/587,002. In contrast, a standard printing operation with conventional nozzles adapted to print a 20 mil wide path would require approximately 76 hours to print the illustrated hood. Therefore, the printing time is reduced by 3 times or more.

Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the disclosure.

Claims (19)

1. An additive manufacturing system for printing a three-dimensional part, the additive manufacturing system comprising:

a chamber having a first length and comprising a chamber wall and a lateral port providing an opening in the chamber;

a heating mechanism configured to heat the chamber of the additive manufacturing system to one or more temperatures;

a printhead configured to print a component material along a non-vertical printing axis;

a non-horizontal receiving surface configured to receive printed part material from the printhead in the chamber to produce the three-dimensional part in a layer-by-layer manner, the three-dimensional part having a second length; and

a drive mechanism configured to guide the receiving surface along the non-vertical printing axis such that the receiving surface and at least a portion of the three-dimensional part move out of the chamber through the lateral port as the three-dimensional part is being built in a layer-by-layer manner while the second length of the three-dimensional part is greater than the first length of the chamber.

2. The additive manufacturing system of claim 1, wherein the non-vertical printing axis comprises a substantially horizontal printing axis, and wherein the non-horizontal receiving surface comprises a substantially vertical receiving surface.

3. The additive manufacturing system of claim 1, wherein the receiving surface is a surface of a platen of the additive manufacturing system, and wherein the drive mechanism comprises a platen gantry having a first end disposed in the heated chamber and a second end disposed outside the heated chamber.

4. The additive manufacturing system of claim 3, wherein the platen gantry comprises at least one guide rail extending through the lateral port along the non-vertical printing axis, the at least one guide rail configured to limit movement of the platen to a direction generally along the non-vertical printing axis.

5. The additive manufacturing system of claim 1, wherein the receiving surface is a surface of an actuator, and wherein the drive mechanism engages the actuator only along a side surface of the actuator.

6. The additive manufacturing system of claim 1, wherein the drive mechanism comprises a rotatable belt, and wherein the receiving surface is a surface of the actuator wedge that is secured to the rotatable belt.

7. The additive manufacturing system of claim 6, further comprising one or more post-printing processing stations, wherein the rotatable band extends through the one or more post-printing processing stations.

8. The additive manufacturing system of claim 1, wherein the printhead comprises an auger-based viscous pump.

9. The additive manufacturing system according to claim 1, wherein a zone of the additive manufacturing system comprises a plurality of consecutive chambers, which chambers are heatable to different temperatures to define a stepwise decreasing temperature gradient.

10. The additive manufacturing system of claim 9, wherein at least a portion of the plurality of consecutive chambers have a variable size.

11. A method of printing a three-dimensional part with an additive manufacturing system, the method comprising:

providing a chamber having a first length and comprising a chamber wall and a lateral port providing an opening in the chamber;

printing, in a layer-by-layer manner, a three-dimensional part and a skeleton on a receiving surface along a non-vertical printing axis, wherein the skeleton vertically supports at least a portion of the three-dimensional part having a second length during printing; and

in conjunction with printing the three-dimensional part and the skeleton, guiding the receiving surface along a non-vertical printing axis such that at least a portion of the three-dimensional part and the skeleton are guided out of the chamber through the lateral port as the three-dimensional part is being built in a layer-by-layer manner while the second length of the three-dimensional part is greater than the first length of the chamber.

12. The method of claim 11, further comprising printing a support structure along a non-vertical printing axis in a layer-by-layer manner on the receiving surface, wherein printing the three-dimensional part and the skeleton on a print substrate comprises printing the three-dimensional part and the skeleton on the support structure.

13. The method of claim 11, further comprising heating a chamber of an additive manufacturing system.

14. The method of claim 13, further comprising heating a second chamber of an additive manufacturing system to define a stepped-down temperature gradient between the chamber and the second chamber.

15. The method of claim 11, wherein the skeleton comprises a strip having a wave pattern, the strip being connected to the three-dimensional part at one or more tangent locations of the strip.

16. The method of claim 15, wherein the skeleton further comprises a conveyor substrate connected to the strap portion opposite the three-dimensional component.

17. The method of claim 16, further comprising:

engaging the conveyor base with a drive mechanism of the additive manufacturing system; and

guiding the backbone along a non-vertical printing axis with the drive mechanism engaged.

18. The method of claim 11, wherein the receiving surface comprises a surface of a platen or a surface of an actuator of the additive manufacturing system.

19. The method of claim 11, wherein guiding the receiving surface along a non-vertical printing axis comprises rotating a belt holding the receiving surface.