WO2015024117A1

WO2015024117A1 - Flashless blow molding with one sized end-cuff

Info

Publication number: WO2015024117A1
Application number: PCT/CA2014/050790
Authority: WO
Inventors: Danny Cacciacarro
Original assignee: Salflex Polymers Ltd
Current assignee: Salflex Polymers Ltd
Priority date: 2013-08-21
Filing date: 2014-08-18
Publication date: 2015-02-26
Anticipated expiration: 2016-02-21

Abstract

A molding system and associated method for blow molding a hollow article. The molding system comprises mold tooling having a first mold half and second mold half. The first and second mold halves together define a cavity for blow molding a hollow article. The molding system provides a swing-table positioned in operational relationship to the first and second mold halves. The swing table enables manipulation of a parison delivered to the mold tooling so as position the parison within the cavity defined therein. The swing table is further configured to present to the parison a mandrel enabling compression molding of at least a portion of the parison, thereby forming the hollow article through a combination of compression molding and blow molding.

Description

FLASHLESS BLOW MOLDING WITH ONE SIZED END-CUFF

Field of the Invention

[0001] The present invention relates to a method of manufacturing plastic blow-molded parts, and in particular to a flashless blow molded duct having an end-cuff of sized internal diameter.

Background of the Invention

[0002] Hollow articles for use in automotive applications often use conventional blow molding during the manufacturing process. Following the blow molding operation, post-mold processing is performed to trim the article to the finished dimensions. Post-molding processing increases overall cycle time for unit production, having the effect of increased overall cost. Post-mold processing also has the potential to introduce into the finished article debris which could have detrimental effect to the larger operating system (e.g. engine) during use.

Summary of the Invention

[0003] According to an aspect of an embodiment, provided is a molding system for blow molding a hollow article. The molding system comprises mold tooling having a first mold half and second mold half. The first and second mold halves together define a cavity for blow molding a hollow article. The molding system also provides a swing-table positioned in operational relationship to the first and second mold halves. The swing table enables manipulation of a parison delivered to the mold tooling so as position the parison within the cavity defined therein. The swing table is further configured to present to the parison a mandrel enabling compression molding of at least a portion of the parison.

[0004] According to another aspect of an embodiment, provided is a method for molding a hollow article, the method comprising extruding a hollow parison into a mold tool defining a cavity; closing a portion of said mold tool to capture a portion of said parison within a first portion of said cavity; engaging a distal end of said parison using a swing table; expanding said distal end of said parison sufficiently to enable insertion into said distal end a mandrel positioned on said swing table; moving said swing table from a first position to a second position, so as to urge said parison into position within a second portion of said cavity; closing remaining segments of said mold tool around said parison; compression molding said distal end of said parison between said mandrel and said cavity and introducing pressurized fluid into said parison so as to urge the remaining portions of said parison against said cavity to form the desired hollow article.

Brief Description of the Drawings

[0005] The foregoing and other features and advantages of the invention will be apparent from the following description of the invention as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. The drawings are not to scale.

[0006] Fig. 1A is a schematic parting-line view of the molding system showing the component parts in a first operating stage.

[0007] Fig. IB is a schematic side view of the molding system of Fig. 1A.

[0008] Fig. 1C is a side view of an exemplary automotive clean-air duct forming using the molding system of Fig. 1A.

[0009] Fig. 2A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a second operating stage.

[0010] Fig. 2B is a schematic side view of the molding system of Fig. 2A.

[0011] Fig. 3 A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a third operating stage.

[0012] Fig. 3B is a schematic side view of the molding system of Fig. 3A.

[0013] Fig. 4A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a forth operating stage.

[0014] Fig. 4B is a schematic side view of the molding system of Fig. 4A. [0015] Fig. 5A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a fifth operating stage.

[0016] Fig. 5B is a schematic side view of the molding system of Fig. 5 A.

[0017] Fig. 6A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a sixth operating stage.

[0018] Fig. 6B is a schematic side view of the molding system of Fig. 6A.

[0019] Fig. 7 is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a seventh operating stage.

[0020] Fig. 8 is a schematic parting-line view of the molding system of Fig. 1 A, showing the component parts in a eighth operating stage.

[0021] Fig. 9 is a schematic side view of the molding system of Fig. 1A, showing the component parts in a ninth operating stage.

[0022] Fig. 10 is a schematic side view of the molding system of Fig. 1A, showing the component parts in a tenth operating stage.

[0023] Fig. 11A is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a eleventh operating stage.

[0024] Fig. 1 IB is a schematic side view of the molding system of Fig. 11 A.

[0025] Fig. 12 is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a twelfth operating stage.

[0026] Fig. 13 is a schematic parting-line view of the molding system of Fig. 1A, showing the component parts in a thirteenth operating stage.

[0027] As will be appreciated, the operating positions depicted in the figures are exemplary, and are presented for the purpose of explaining the technology. The molding system described below may in fact consist of additional, or fewer operating positions. As will be appreciated, there may be some variability in the order/timing of the various mold functions. It should be understood that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all such variations falling within the spirit and scope of the invention.

Detailed Description of Embodiments of the Present Invention

[0028] Specific embodiments of the present invention will now be described with reference to the Figures, wherein like reference numbers indicate identical or functionally similar elements. The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the scope of the invention. Although the description and drawings of the embodiments hereof exemplify the technology in the form of a molding machine intended for manufacturing automotive ducts, the invention may also be used in the manufacture of other automotive/non- automotive molded plastic structures. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

[0029] For the purposes of this description, the term 'forwardly' is defined as displacement towards the parison, and the term 'rearwardly' is defined as displacement away from the parison.

[0030] Generally, the present invention is a blow-molding system designed for manufacturing automotive clean-air ducts. The system is configured to be generally flashless, so as to reduce material waste, and achieve decreased labour costs and production time. In addition, the system is configured to mold the clean-air duct with an end-cuff having a predetermined finished internal diameter. End-cuff finish molding within the overall molding process serves to reduce and/or eliminate the need for post-mold processing, thereby further reducing labour costs and production time.

[0031] In addition to mold tooling defining a mold cavity, the system incorporates a multifunctional swing table, capable of directing an extruded parison into the molding cavity, as well as molding the aforementioned end cuff. While the clean-air duct is predominantly blow molded to conform to the interior surface of the mold cavity, the terminal region of the extruded parison is subject to a compression molding process via a core, so as to define the end-cuff having the finished internal diameter, and if desired, any additional molded features, such as a sealing bead.

[0032] Turning now to Figs. 1A and IB, shown are schematic views of molding system 10. Specifically, Fig. 1A presents molding system 10 as viewed along parting line P, while Fig. IB presents molding system 10 as viewed along lines A-A of Fig. 1A. Molding system 10 generally includes mold tooling 12 comprising first mold half 20 and second mold half 22. In the embodiment shown, each mold half includes multiple independently displaceable mold segments. In particular, first mold half 20 includes primary segment 24a, secondary segment 26a and cuff segment 28a. Similarly, second mold half 22 includes primary segment 24b, secondary segment 26b and cuff segment 28b. Molding system 10 also includes extruder 30 designed to provide a cylindrical parison 32 to mold tooling 12. As shown, extruder 30 is positioned directly in line with mold tooling 12 so as to extrude parison 32 directly between first and second mold halves 20, 22. As will be appreciated, molding system 10 may implement an alternate arrangement for parison delivery. For example, the molding system may be configured with a suitable conveying device (not shown) to deliver an extruded parison from a separately located extruder. An exemplary conveying device would be a robotic assembly system fitted with end- of-arm tooling suitable for handling a parison, such as a gripper assembly. A variety of configurations are possible for the gripper assembly, as known in the art. In general, the gripper assembly would be configured to grasp and release the top end of the parison to permit for parison transport and control

[0033] Continuing with Figs. 1A and IB, molding system 10 provides multifunctional swing table 34. Swing table 34 is both forwardly/rearwardly displaceable, and capable of arcuate motion from a first position (as shown for example in Fig. IB) through to a second position (as shown for example in Fig. 5B). The swing functionality of swing table 34 enables manipulation of parison 32 for proper positioning between first and second mold halves 20, 22 of mold tool 12, and may be achieved through the use of a suitable articulation or tilt mechanism. For example, articulation of swing table 34 may be performed by way of a 6-axis robot, wherein swing table 34 is provided in the form of end-of-arm tooling. Alternatively, a dedicated tilt mechanism may be employed, where the table and associated components are mounted on a tiltable frame, generally guided by one or more arcuate support surfaces for moving the tiltable frame and thereby swing table 34 through the aforementioned first and second positions.

[0034] Swing table 34 also comprises displaceable core or mandrel 36, and a plurality of expansion fingers 38. Mandrel 36 and expansion fingers 38 engage the distal end of parison 32 as will be described in greater detail below. Mandrel 36 is displaceable relative to swing table 34 from a first retracted position, as shown in Fig. 1A, to a second extended position, as shown in Fig. 4A. Expansion fingers 38 are also displaceable from a first retracted position, as shown in Fig. 1 A, and a second expanded position, as shown in Fig. 3A. Displacement of mandrel 36 and expansion fingers 38 is achieved by way of suitably located actuators (not shown for clarity). Also provided on mandrel 36 is a blow pin 40 for delivering a pressurized fluid (i.e. air) into parison during the preblow/blowing stages of the manufacturing process.

[0035] In the embodiment shown, mold tooling 12 produces the automotive clean-air duct 42 shown in Fig. 1C. As will be appreciated, the design of clean-air duct 42 is merely exemplary, and may take on a variety of forms. As provided here, clean-air duct 42 comprises bellows 44, unfinished end-cuff 46, elbow 48 and finished end cuff 50. Accordingly, having regard to mold tool 12, primary mold segments 24a/b provide mold cavities 52a/b that together define bellows 44 and unfinished end-cuff 46; secondary mold segments 26a/b provide mold cavities 54a/b that together define elbow 48; and cuff-segment 28a/b provides mold cavities 56a/b that together define finished end-cuff 50.

[0036] Figs 1A/1B present mold tool 10 in the ready position to receive parison 32. Mold segments 24a/b, 26a/b and 28a/b are open, and swing table 34 is located in the first position. Accordingly, extruder 30 extrudes parison 32 downwardly between mold halves 20, 22 sufficiently to engage swing table 34, as shown in Figs 2A/2B. As shown, expansion fingers 38 are positioned inside the end region of parison 32.

[0037] Expansion fingers 38 are then displaced outwardly to securely engage parison 32, thereby physically expanding the end region of parison 32, as shown in Fig. 3A/3B. Either simultaneously with end region expansion of parison 32, or subsequent thereto, swing table 34 displaces downwardly to the position shown in Figs. 4A/4B. In addition, primary mold segments 24a/b close upon parison 32, thereby pinching the top region thereof, and securing parison 32 within this upper region of mold tool 12. Once again either simultaneously with downward displacement of swing table 34, or subsequent thereto, parison 32 is subject to a preblow operation via blow pin 40. During this preblow operation, mandrel 36 is displaced upwardly into parison 32, further expanding the end region.

[0038] Referring now to Figs. 5A/5B, the swing functionality of swing table 34 is shown. As noted more clearly in Fig. 5B, swing table 34 is moved via a suitable articulation/tilt mechanism (not shown) from position 1 through to position 2, thereby facilitating alignment of parison 32 with mold cavities 54a/b, 56a/b. With parison 32 in position, secondary mold segments 26a/b are closed, as shown in Figs. 6A/6B, followed by cuff-segments 28a/b, as shown in Figs. 7. With closure of cuff-segments 28a/b, parison 32 is compression molded against mandrel 36, thereby establishing a predetermined inside diameter for finished end-cuff 50 of clean-air duct 42, as determined by the outside dimensions of mandrel 36. The remainder of parison 32 is then urged against the molding surfaces of cavities 52a/b and 54a/b by subjecting parison 32 to a pressurized fluid via blow pin 40, as shown in Fig. 8.

[0039] Following sufficient hold time, mandrel 36 and expansion fingers 38 are retracted, as shown in Figs. 9 and 10, respectively. With mandrel 36 and expansion fingers 38 disengaged from the formed article, in this case clean-air duct 42, cuff-segment 28a/b is opened, and swing table 34 is displaced outward away from mold tooling 12, as shown in Figs, 11 A/1 IB. The remaining mold segments, namely primary and secondary mold segments 26a/b, 28a/b are then opened to release clean-air duct 42 as shown in Figs. 12 and 13. With the release of clean-air duct 42, molding system 10 is then returned to the ready position as presented in Figs. 1 A/IB.

[0040] It will be appreciated that while mandrel 36 is shown as a solid structure of fixed dimension, mandrel 36 may also be collapsible or partially collapsible to facilitate detachment/ withdrawal of the mandrel from the molded article. In particular, where a surface feature (i.e. sealing bead) is compression molded onto the inside surface of the molded article, the use of a collapsible mandrel would reduce the likelihood of shearing on rearward displacement of the mandrel.

[0041] It will also be appreciated that the process steps presented above are exemplary in nature, and that additional processing steps may be incorporated. For example, once again in relation to the mandrel, to facilitate detachment/withdrawal, the molded article may be subject to an air- blow pulse to temporarily expand the molded article as the mandrel is rearwardly displaced. The air-blow pulse may be delivered through the use of air outlets provided on the molding surface of the mandrel. To enable the temporary expansion of the molded article during the air-blow pulse, the surrounding mold tooling, and in this case the respective cuff segments may be at least partially retracted.

[0042] It will be appreciated that the automotive clean-air duct manufactured by molding system 10 is merely exemplary. While each mold half of mold tooling 12 is comprised of three mold segments, other embodiments of the mold tooling may comprise a fewer or greater number of mold segments, depending on the hollow article being formed. It will also be appreciated that while the system has been exemplified with respect to the manufacture of an automotive clean- air duct, the system may find application in a the manufacture of a range of other automotive hollow articles, for example, but not limited to turbo air ducts and HVAC ducts.

[0043] While the compression molding operation enabled via the swing table is described above having regard to the finished internal diameter, it will be appreciated that the compression molding operation also facilitates the formation of a finished and predetermined outside diameter for the finished end-cuff

[0044] It will also be appreciated that the manufacturing process described herein is applicable to both single material parisons, as well as multi -material and/or multi-layered parisons.

[0045] While various embodiments according to the present invention have been described above, it should be understood that they have been presented by way of illustration and example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-descried exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents. It will also be understood that each feature of each embodiment discussed herein, and of each reference cited herein, can be used in combination with the features of any other combination. All patents and publications discussed herein are incorporated by reference herein in their entirety.

Claims

CLAIMED

1. A molding system for blow molding a hollow article, the molding system comprising: mold tooling having a first mold half and second mold half, first and second mold halves together defining a cavity for blow molding a hollow article; a swing-table positioned in operational relationship to the first and second mold halves; wherein said swing table enables manipulation of a parison delivered to the mold tooling so as position the parison within the cavity defined therein; and wherein the swing table in configured to present to the parison a mandrel enabling compression molding of at least a portion of the parison.

2. The molding system according to claim 1, wherein each of the first and second mold halves generally comprises a plurality of displaceable mold segments.

3. The molding system according to claim 1, wherein said swing table is both forwardly and rearwardly displaceable relative to said parison.

4. The molding system according to claim 1, wherein said swing table is configured to undergo arcuate motion, enabling manipulation and placement of said parison between said first and second mold halves.

5. The molding system according to claim 4, wherein said arcuate motion of said swing table is performed by way of a robot.

6. The molding system according to claim 4, wherein said arcuate motion of said swing table is performed by way of a tiltable frame, guided by one or more arcuate support surfaces.

7. The molding system according to claim 1, wherein said swing table further comprises a plurality of displaceable expansion fingers to enable expansion of an end region of said parison.

8. The molding system according to claim 1, wherein said compression molding is performed between said mandrel and said cavity to define a predetermined inside diameter for and end-cuff portion of said hollow article.

9. The molding system according to claim 1, wherein said swing table additionally comprises a blow pin to deliver a pressurized fluid into said parison.

10. A method for molding a hollow article, comprising extruding a hollow parison into a mold tool defining a cavity; closing a portion of said mold tool to capture a portion of said parison within a first portion of said cavity; engaging a distal end of said parison using a swing table; expanding said distal end of said parison sufficiently to enable insertion into said distal end a mandrel positioned on said swing table; moving said swing table from a first position to a second position, so as to urge said parison into position within a second portion of said cavity; closing remaining segments of said mold tool around said parison; compression molding said distal end of said parison between said mandrel and said cavity; introducing pressurized fluid into said parison so as to urge the remaining portions of said parison against said cavity to form the desired hollow article.