CN1681656A - Equipment for spraying ink marks onto wooden boards - Google Patents

Abstract

An apparatus for applying a pattern of ink to a wood board wherein the wood boards are advanced one by one in a predetermined space adjacent to an ink jet head which applies ink to the wood boards. To accurately apply the ink to the board, the board is advanced between the drive roller and the platen roller to ensure that the board is flat as it passes under the ink jet head. The detection device is used for detecting whether the wood board is flattened and whether the shape of the wood board has irregularities, and if the wood board is detected to be uneven or irregular, the ink jet head is moved away to avoid being damaged by the wood board. In the spraying operation, the distance from the ink-jet head to the wood board is about 0.0625-0.125 inches, and the travel speed of the wood board is about 150 and 600 feet/minute.

Description

Equipment for spraying ink marks onto wooden boards

Background of the Invention

Wood planks and veneers, typically made from wood composite products such as laminates or oriented strand boards, are a common construction material in commercial, industrial and residential buildings. During construction, such panels are placed and fastened to a support frame beneath or behind them to form the walls, roof or floor of a building. In order to improve the efficiency of fixing the plank to the skeleton, a graphic mark can be sprayed on the plank, so as to quickly fix the plank to the skeleton structure.

Typically, in the final stage of the manufacturing process of the wooden board, that is, before the wooden board is packed and ready to be shipped, the required graphic marks are sprayed on the wooden board with ink. Most board manufacturers carry out this marking step at almost the same speed as the inspection of the boards for defects so as not to affect or hinder the production of the boards. Unfortunately, such high marking speeds reduce the accuracy and legibility of the patterns that may be formed during the marking process, which can result in simplistic and crude markings. While such pictographs may provide a minimum useful set of reference points, they do not maximize the generality of the product, nor do they impart any specificity to the product.

One way to improve this marking process is to reduce the distance between the surface of the wood board and the print heads of the printing system (usually such printing systems include several print heads) that spray ink onto the wood board (commonly referred to as the "ink jet distance"). "). When the inkjet distance is small, it is possible to form more precise and legible graphic marks on the wood board, but such a small distance between the board surface and the printing head also increases the possibility that, during the manufacturing process Boards that are out of tolerance, warped, out of alignment, or of uneven thickness can accidentally hit the print head and severely damage or damage it. Therefore, there must be a consistent gap between the board and the print head. Moreover, fluctuations in the thickness and height of the wood board may also affect the accuracy of ink spraying on the expected position of the wood board, thereby reducing the quality of the graphic marks formed on the wood board surface.

Therefore, there is a need for an apparatus capable of spraying ink onto the printing surface of a wood board, wherein the distance between the wood board and the ink spraying system is small, and can be used for precise printing of complex graphic marks and patterns at high production speeds. Clear and easy to read printing. Furthermore, there is a need for such equipment to have means to apply vertical force to the printing surface of the board at several locations to maintain the printing surface of the board in a flat, planar shape which increases ink spraying during printing. Positional accuracy on the surface, thereby improving the quality of graphics, markings and decorative patterns formed on the printed surface of wood boards.

Summary of the invention

The invention provides a device for spraying ink graphic marks on a wooden board, which includes: a device for making the wooden boards pass through a predetermined space along a selected direction one by one; means, the inkjet device is movable from its first position close to said predetermined space to its second position away from said predetermined space; and for detecting whether there is a part of the plank traveling along said selected direction means beyond the intended space. The apparatus also includes moving the inkjet device from the first position to the first position in response to the detecting means when the detecting means detects that a portion of the plank traveling along the selected direction exceeds the predetermined space. The device for the second position, so as to prevent the moving wooden board from colliding with the inkjet device; and the device for controlling the inkjet device to spray ink and graphic marks on the wooden board traveling in the predetermined space.

A feature of the apparatus of the present invention is that it is capable of applying ink graphic markings to planks traveling at a speed of 150-600 ft/min.

Another feature of the present invention is that the ink can be accurately sprayed at a prescribed location on a traveling plank with a location accuracy of not more than 0.125 inches.

A brief description of several attached drawings

The foregoing summary, together with the following detailed description of the embodiments of the invention, will be better understood when read with reference to the accompanying drawings. For the purpose of illustrating the invention, what are presently considered to be the preferred embodiments of the invention are shown in the drawings. It should be understood, however, that the present invention is not strictly limited to the presented structural arrangements and implementation means. In the attached drawings:

Fig. 1 is the perspective view of the structural arrangement of a preferred embodiment of the equipment for spraying ink to wooden board of the present invention;

Figure 2 is a partial side view of the device showing the movable carriage of the device of the present invention; and

Figure 3 is a rear perspective view of a modified apparatus of the present invention.

Detailed description of the present invention

All documents mentioned in this article are to be cited.

The term "wood panel" as used herein includes planks and thin panels, which are usually made from wood composites such as laminates or oriented Made from a mixture of resistant materials.

"Wood composite" means a composite material comprising wood and one or more additives such as a binder or wax. In wood composites, wood is usually in the form of flakes, flake powder, wood strips, shavings, pellets and chips. Non-limiting examples of wood composites include oriented strand board (OSB), veneer board, particle board, particle board, medium density fiberboard, laminate, and those boards that are composites of wood strands and wood chips. As used herein, "flaky powder", "wood strips", "chips", "granules" and "chips" are considered equivalent to each other and may be used interchangeably herein. A non-proprietary description of wood composites can be found in the Supplement Volume to the Kirk-Rothmer Encyclopedia of Chemical Technology, pp765-810, ^6th Edition.

The present invention aims to provide a device for spraying ink on a wooden board to form simple marks and graphics as well as more complex decorative patterns. Typically such boards are made from wood composite materials, especially OSB boards. In profile, these boards typically measure 4 feet wide by 8 feet long, 0.25-1.5 inches thick, and a board weighs 20 to 200 pounds. In such an apparatus, the board is moved through a predetermined space adjacent to which a means for applying ink to the printing surface of the board is in its first position. The device also includes a means for detecting whether a part of the plank protrudes beyond said predetermined space (for example due to warpage or uneven thickness of the plank), and a means capable of detecting that the plank is traveling along a selected direction when the detecting means detects A device that moves the inkjet device from its first position to a second position in response to a detection device when a part of the wood board exceeds a predetermined space, so as to prevent the moving wood board from colliding with the inkjet device, thereby preventing damage to the inkjet device devices and the electronics contained therein. As a second form of protection for the ink-jet device, it is preferable to provide a plurality of platen rollers for pressing the board moving through a predetermined space against a plurality of driving rollers. The drive rollers are arranged to contact the planks at various points in a common plane and rotate around several mutually parallel axes to advance the planks one by one.

By applying these protective mechanisms in combination, as well as other devices discussed below, it is possible to greatly reduce the distance between the wood board and the inkjet device (ink ejection distance), thereby improving the quality of marks and patterns formed by the ink on the wood board, Moreover, the risk of damaging the inkjet device can be greatly reduced. Also, due to the reduction of the space between the inkjet device and the wood board, the speed of marking the wood board can be increased.

There are platen rollers pressing the board against a plurality of drive rollers to maintain the shape of the printing surface of the board in a plane during the passage of the board through a predetermined space under the inkjet device. By maintaining the printing surface in such a shape, the accuracy and legibility of graphics and patterns printed by the inkjet device on the wood board can be improved.

Turning now to Figure 1, there is shown a preferred embodiment of an apparatus 1 for printing indicia on boards. The plant 1 comprises a support frame 11 (partially shown) for supporting planks 4 which travel through the plant 1 one by one. A preferred support frame 11 is a Globe ^(TM) 16Q platen assembly manufactured by Globe Machine Manufacturing, Tacoma, Washington, USA. This supporting frame 11 can transport the wooden board 4 from the final stage of the OSB board production line (not shown) along the selected direction 23 to the predetermined space 17, where the ink is sprayed on the printing surface 20 of the wooden board 4 (printing surface). 20 is sprayed on the plank 4 and prints the area of mark or pattern). Predetermined space 17 is a rectangular space, its length and width are adapted to the length and width of the inkjet device, and the thickness of predetermined space 17 is approximately equal to the thickness of the plank to be sprayed plus the required inkjet distance.

The plant 1 also includes means for advancing the planks one after the other along a selected direction 23 . The means for advancing the boards includes an electric motor 50 controlled by the controller 44 and a mechanical transmission (not shown) connecting the electric motor 50 to a plurality of drive rollers 26 . The drive rollers 26 are mounted on four shafts 62 below the height of the plank, preferably each drive roller 26 is made of steel and covered with a layer of rubber, or is made of some material that reduces slippage. , so that the board can be driven forward by friction.

Preferably, the means for advancing the planks one after the other further comprises a plurality of platen rollers for pressing the planks passing through the predetermined space 17 in the selected direction 23 against respective drive rollers. As shown in each figure, the platen rollers 29 are mounted on several axles positioned above the height of the plank 4, and each platen roller 29 is aligned with each drive roller 26 in the vertical direction. In operation, each platen roller 29 contacts the wood board 4 and applies a substantially vertical biasing force to the printing surface of the wood board 4 while maintaining the printing surface as a flat surface to improve the accuracy of ink spraying onto the printing surface. It is desirable that the biasing force be evenly distributed across the board, yet not interfere with the desired printed pattern. Platen rollers 29 are set at a predetermined vertical spacing from drive rollers 26, and are spring or pneumatic actuator set to a predetermined amount of compression to maintain the biasing force of the platen rollers on the plank surface. With this configuration, the plank can be in the flattest state to ensure a uniform printing gap (ink jetting distance) when the plank travels on the drive roller 26, and slippage can be minimized to improve speed control accuracy. It should be noted that in order to represent the exact position and spacing of the platen rollers 29 above the plank, the supporting structure of the platen rollers 29 is not depicted in FIG. 1 . Those skilled in the art will be able to devise structures that both support platen rollers 29 and allow them to rotate freely. The rotation of platen roller 29 is driven by drive motor 50 by plank. The support structure for the platen rollers 29 may or may not be part of the components of the support frame 11 .

As the rollers 26 are driven to advance the board 4 in the selected direction 23, each platen roller 29 applies a vertical force to the printing surface 20 of the board 4 to flatten it, and the boards 4 move one by one through the apparatus 1 and predetermined space17. When the inkjet device was in its first position, the inkjet device was close to the predetermined space 17, as shown in Figure 1 (in this figure, the inkjet device is represented as an inkjet printing head mounted on the mounting plate 35, to which detailed below). As the wooden board 4 enters the predetermined space 17, the mark is printed on the wooden board 4 by the inkjet device. The inkjet device can be moved from the first position to a second position away from the predetermined space 17, so that the inkjet device is moved away, in case a part of the plank 4 moving in the selected direction 23 exceeds the predetermined space 17 (Mostly due to the warping or uneven thickness of the wood board), it can avoid damage to the inkjet device.

In order to utilize the flexible mobility of the inkjet device, the present invention also includes a device for detecting whether a part of the board exceeds the predetermined space 17, and a device capable of moving the inkjet device from its first position to its first position in response to the detection device. device in the second position. The detection means monitors the plank 4 moving in the selected direction 23, and if a part of the plank 4 is outside the predetermined space 17 (in particular too close to the inkjet means), the means responsive to the detection means will move the inkjet means from its The first position is moved to its second position out of the danger of possible collision. As the detection means in the device 1, analytical detection equipment such as a disconnect switch, a laser device, an acoustic system or any other suitable form can be used. If the detection device detects that a part of the plank exceeds the predetermined space 17, it sends a signal to the device of the response detection device, and the latter moves the inkjet device from its first position to its second position to prevent it from being damaged. damage. Instead of electronic, acoustic or optical sensing systems, mechanical mechanisms such as springs are also possible, as will be discussed below.

The inkjet device includes a bracket 32 pivotably connected to the support frame 11 . The carriage 32 has a mounting plate 35 on which a plurality of inkjet printing heads 38 are mounted. Preferably, the inkjet print heads 38 are oriented in a consistent printing direction for ease of generation of graphic information and for best printing accuracy. Installation in the form of a modular plate can facilitate the replacement of spare parts and reduce manufacturing costs. Each inkjet print head 38 is preferably mounted to be buried a little bit in the bottom surface of the mounting plate 35 so that it does not come into contact with debris, shavings, sawdust or the like on the surface of the board. However, they may be installed flush with the bottom surface of the mounting plate 35 in order to reduce the ejection distance. In order to increase the resolution of indicia and decorative patterns printed on the wood board, it is preferable to mount the ink jet device such as the ink jet print head 38 at a distance of about 0.0625-0.125 inches from the printing surface of the wood board 4 .

In some cases, a part of the board may be slightly beyond the predetermined space 17, in this case, instead of removing the inkjet device, a deflector (deflector) 101 can be used to guide the part of the board to the predetermined space. In the space 17 of the space 17, the interference to the ongoing marking operation is minimal. Deflector 101 is best shown in FIG. 2 . The deflector 101 in FIG. 2 is a sloped guide edge 101 mounted on the bracket 32 . This provides yet another way to prevent the board from damaging the inkjet unit, and this protection mechanism has the advantage of not interfering with the printing operation. Indeed, in this aspect of the invention, the substantial mass of the mounting plate 35 effectively absorbs shocks, thereby further protecting the inkjet device, such as the inkjet printhead 38.

Figures 1 and 2 also show detection means for detecting whether a part of the plank exceeds the predetermined space 17, and can respond to the detection means when the detection means detects that the plank traveling in a selected direction exceeds the predetermined space 17. A device for moving an inkjet device from its first position to its second position. In particular, the bracket 32 is pivotally connected to the vertical strut 104 at a pivot seat 110 which is positioned adjacent to the free end of the strut 104 . One end 119 of the coil spring 113 is hooked on the post 104 below the pivot seat 110 , and the other end 116 of the spring 113 is hung near the bracket 32 and close to the non-connecting end of the mounting plate. When the equipment 1 works in a normal printing mode (that is, the carriage 32 is in the first position shown by the solid line in the figure) and sprays ink on the wooden board 4, the mounting plate 35 is positioned above the predetermined space 17 and is substantially parallel on the printing surface of the board 4. When the bracket 32 is in the first position, the spring 113 is in a state of being compressed and storing energy. In addition, a fast stop 107 is provided to limit the counterclockwise movement of the mounting plate 35 from exceeding a prescribed range.

During operation, as the plank 4 advances along the selected direction 23, if a part of the plank exceeds the predetermined space 17 so that the plank contacts the bracket 32 with a limited force (described in detail below), then the kinetic energy of the plank Part of it is delivered to the spring 113. Then the spring 113 stretches and converts the accumulated potential energy into kinetic energy, so that the carriage 32 pivots clockwise away from the predetermined space 17 and arrives at its second position, so that the plank 4 passes through the predetermined space 17 without bumping into the inkjet printing head 38 (In FIG. 2, the second position of the mounting plate 35 is indicated by a dotted line).

Thus, the detection means comprise the deflector 101 and the mechanical action of the spring. If the force of the plank 4 contacting the bracket 32 is large enough to be greater than the force exerted by the compressed spring 113, the spring 113 is elongated from the compressed state and causes the bracket 32 to rotate clockwise around the pivot seat 110 until the It reaches the second position, which is a balance point, at which point the spring 113 is in tension, and the outward pulling force of the spring is balanced with the weight of the bracket 32 . Therefore, the force (spring stiffness) of the spring 113 itself determines the size of the force required to make the mounting plate 35 start to move, so the spring 113 is acting as a detection device, which can determine how much the plank exceeds the predetermined space 17. Turn bracket 32 away. It should be noted that the spring 113 is also part of the means for moving the inkjet device (which includes the carriage 32) from the first position to the second position in response to the detection means. Instead of springs, gas shock absorbers can also be used to determine the force required to rotate the bracket 32 . When a gas shock absorber is used, the magnitude of the preload force applied to it can be precisely controlled, and thus the sensitivity of the bracket 32 to possible collisions can be precisely specified. In addition, the device 1 preferably includes a handle 99 to allow manual adjustment of the position of the bracket 32 .

The apparatus 1 also includes vertical adjustment means for adjusting the distance between the inkjet means and the printing surface of the wood board (inkjet distance). This distance can be adjusted smaller to improve print quality, or larger to accommodate thick wood or boards that vary widely in thickness. Although not shown in the drawings, it should be understood that vertical adjustment can be made with several linear operators driven by a common shaft to ensure parallel height adjustment. Vertical adjustments can be monitored with height gauges. The linear operating mechanism is preferably electric or pneumatic.

As mentioned above, the inkjet device preferably employs inkjet technology. Preferably, there is an inkjet device with multiple inkjet heads. The multiple inkjet heads include multiple valves, and each valve can spray ink onto the printing surface 20 of the wood board 4 . These ink marks are deposited on the board in the form of graphics, simple geometric figures such as triangles, squares or circles, or more complex figures such as decorative patterns, figures, or to indicate the brand name of the product or Manufacturer's special characters. The number of valves on the printhead determines whether the printhead can be used to form ink marks and graphics or larger and more complex decorative patterns. In a preferred embodiment shown in FIG. 1, a plurality of ink jet print heads 38 are supported on a mounting plate 35. As shown in FIG.

The apparatus of the present invention also includes control means for controlling the inkjet means for spraying the ink pattern onto the wooden board 4 traveling in the predetermined space 17 . The control means are preferably coordinated by a computerized controller 44, although automation is not required. The print controller 44 is preferably programmed and controlled by the user via keypad entry, touch screen (not shown), or other input device placed outside its housing. Other suitable input devices connected serially to the printing controller in a PC can also be used. The printing of specific graphics on the board 4 can be controlled and programmed with an advanced computer control interface unit with a computer keyboard.

Off-the-shelf inkjet heads and print controllers are available and can be retrofitted from commercially available items. For example, the Jet-a-Mark ^(R) inkjet system is available from Matthews Corporation, Pittsburgh, Pennsylvania, USA. These inkjet systems form printed characters and graphics on wood boards using drop-on-demand inkjet technology. The inkjet head can have 16 valves (for forming simple graphics on the wooden board) or 32 valves (for forming more complex graphics or special characters on the wooden board). The printing resolution of 6.25-32dpi can be achieved with this system. A computerized controller is available as Jet-a-Mark R4 manufactured by Matthews Corporation, Pittsburgh, Pennsylvania, USA.

The means for controlling the inkjet means may be manual. That is to say, the operator can manually control the movement of the wooden board 4 into the predetermined space 17, and then manually control and trigger the spraying of ink on the printing surface 20 of the wooden board 4 to form marks, graphics and patterns. However, for faster marking, for greater precision in the application of the markings on the printing surface, and for minimizing operator intervention, automated controls are preferred.

During the automated and preferably marking process, the board 4 is pushed by the drive rollers 26 into the predetermined space 17 in a selected direction 23 . The driving rollers 26 can be driven and adjusted by a synchronous (timed) belt (not shown), which synchronizes the speed of the respective driving rollers 26 to keep the board 4 pushed into the predetermined space 17 at a uniform speed. Typically, the synchronous drive belt is a fiber reinforced polymer belt. Timing belts can improve printing accuracy and are superior to sprocket/chain drive systems. Because the sprocket/chain drive system will elongate and wear after a long time of use, and even suddenly fail.

A variable frequency drive (VFD) may be used to vary the speed at which the plank 4 travels through the predetermined space 17 in a selected direction 23 . VFD can increase the speed at which planks are sent into the predetermined space 17, and can make planks that have entered the predetermined space 17 move faster than those that have not yet entered. This ensures that there is a gap between the tails and heads of two successive boards entering the predetermined space 17, which gap allows a photocell (discussed below) to distinguish between two successive boards so that printing can begin at the proper moment. The minimum gap between two successive boards is preferably about 1 inch.

The apparatus of the invention comprises monitoring means for monitoring the movement of the plank along a selected direction 23 into the predetermined space 17 . This monitoring device sends the precise position of the plank and the imminent entry of the plank into the predetermined space 17 to the printing controller 44 in order to start the printing process. The print controller 44 takes into account the position of the board and its speed of movement along the selected direction 23 when controlling the inkjet. The monitoring device that monitors plank motion can adopt multiple suitable technical equipment, but it is better to adopt photoelectric eye.

Figure 1 shows a photo eye (photo eye) 53 mounted below the level of the plank 4 for monitoring the movement of the plank along the selected direction 23 into the predetermined space 17. The photoelectric eye 53 is preferably a split beam photocell (Split-beam photocell) with a modularized narrow beam. When the plank crosses the light beam emitted by the photoelectric eye 53 (or other equivalent monitoring device), the photoelectric eye 53 sends a signal to the printing controller 44, so that it knows the precise position of the plank and starts the printing process. A suitable optoelectronic component is a modified Banner Engineering Mini-beam SM312DSC, available from Matthews Corporation with a fiber optic extension (B6578-503-00). Standard designed brackets can be used to position and support photoelectric components, and mark the starting point of printing according to the front edge of the board.

When the photoelectric element triggers the printing controller to start the printing process, the printing controller also monitors the speed of the wood board 4 moving along the selected direction 23, so that the inkjet device can be properly controlled to print on each printing surface 20 of the wood board 4. Parts form the required combination of graphics and graphics. The speed of the plank can be measured with a number of different devices, but an encoder is best. In the embodiment shown in FIG. 1 , one of the shafts 62 of the drive roller 26 protrudes beyond the hold-down device, and a rotary encoder 56 is mounted directly on the protruding portion of the shaft 62 of the drive roller 26 . Components (optical code readers, sensors or the like, which will be discussed below) for measuring the rotational speed of the encoder 56 are housed in the case 59, but are not specifically shown. By mounting the encoder 56 on the portion of the shaft 62 that protrudes beyond the hold-down means, accumulation of sawdust on the encoder 56 is prevented and distortion due to thermal expansion is also reduced. The information collected by encoder 56 is sent to controller 44 .

Another option for encoder wheel mounting is to use a set of gears attached to a drive belt. In this installation (not shown), the first gear is mounted on the drive roller 26 and is mechanically connected by a belt to the second gear, which is mounted on an external shaft. The gears are given an appropriate ratio to each other so that the outer shaft rotates at almost exactly the same speed as the drive roller 26 on which the first gear is mounted. Then connect the encoder to the external shaft. Due to the distance between the encoder and the marking line in this installation, the accumulation of sawdust and the twisting phenomenon of the change of the diameter of the drive wheel can be reduced to a minimum.

There are markings on the side of the rotary encoder 56, and an optical code reader or sensor can read the markings on the rotary encoder 56 and send the position or speed signal of the plank to the printing controller 44. When the encoder 56 is engaged with the drive roller 26 or it rotates around the drive roller 26, the position or speed signal of the plank is provided to the controller 44, and the controller 44 coordinates the sending of activation signals to the various inkjet valves according to the instructions entered by the operator through it. , instructing each valve to eject ink droplets to print graphics on the wooden board.

The plant 1 may also comprise other optional components, such as means for treating the surface of the wood boards. Such treatment devices include devices for removing dust or other particulate matter from the surface of the boards and other devices such as anti-static equipment. In FIG. 3 , the device for treating the surface of the wooden board includes an air knife 201 capable of removing dust on the printing surface 20 of the wooden board 4 or a brush fixed to a stand. The air knife vigorously sweeps the printing surface of the wood board with an even air flow, removing particles and debris from it. Standard Air Knife ^(TM) and SuperAir Knife ^(TM) air knives manufactured by Exair Corporation, Cincinnati, Ohio, USA can be used. In addition, an antistatic device (such as reference numeral 222 in FIGS. 1 and 3) may be affixed to the support structure for dissipating static charges accumulated on the printed surface of the polished OSB board. If this static charge is not eliminated, the ink droplets will be dispersed during the printing process. When the solvent in the air reaches a certain concentration, there is a danger of explosion. Therefore, it is particularly desirable to remove those static charges. Thin strips of metal foil can be used to remove static charges. The foil strips are pendent copper foil strips secured to a grounded rigid anodized aluminum holder. Such equipment is available from TAKK Industries, Inc., Cincinnati, Ohio, USA.

The apparatus of the present invention preferably also includes a lateral alignment means for aligning the planks with the lateral edges of the frame. This lateral alignment device is used to make the board rest against the lateral edges of the support (204 and 207 in Figure 3), which can ensure that the board is properly aligned so that the ink marks can be printed on the printing surface. Correct position to form simple geometric shapes or more complex graphics. In FIG. 3, the lateral alignment device includes a left fence 210 and a right fence 213 extending parallel to each other. A row of several leaf springs 216 are arranged in front of the left baffle 210, and they press on the left side edge 204 of the plank 4 to push the plank 4 against the right baffle 213, so that each plank 4 advances through the predetermined space At 17 o'clock, the alignment relationship with the inkjet head is always established based on the right edge 204 .

If desired, another air knife 219 can be provided outside the downstream end of the predetermined space 17, ie outside the inkjet device, for accelerating the drying of the ink marks on the printing surface 20 of the board 4 coming out of the predetermined space 17. This additional air knife can be selected from the types of air knives described above.

Any ink suitable for wood boards can be used in the present invention. Preferably, the colorant (pigment or dye) is used to form an incompletely dissolved suspension in a solvent or an ink that is completely dissolved into an emulsion. Preferred solvents are alkyl esters such as alkyl acetate or alkyl butyl acetate. The colorant is preferably a mineral material and preferably of sufficiently high molecular weight so that it does not readily diffuse or migrate through the plasticized covering such as vinyl linoleum. Colorants can be used to form color graphics, as described in U.S. Patent Application 10/012,918, entitled "Boards Comprising an Array of Marks to Facilitate Attachment," filed October 30, 2001, which is incorporated herein by reference. The ink should be resistant to ultraviolet radiation and not easy to fade, fast drying, and the drying time should be within about 1-10 seconds. In addition to colorants, ink may contain several other ingredients such as tackifiers or thickeners, surfactants, polymer binders, opacifiers, preservatives, optical brighteners, plasticizers, Dispersing acid, coagulant and defoamer, etc.

A preferred ink is dry black "non-settling" ink, which is a suspension of pigment particles in an alkyl acetate solvent. This non-settling ink has a viscosity of 2.3-3.5 cps (centipoise) at 80°F and a drying time of about 5 to 10 seconds.

As mentioned above, the ink can be sprayed onto the printed surface of the wood to form signs, bar codes, dates, work crew logos, directions for use, strings of numbers, and decorative patterns. The various markings are preferably arranged in groups for ease of identification, and fasteners (not shown) may be used to secure the planks to the frame structure forming the walls, roof or floor. The markings on the board can be selected to be in various shapes including circles, dots, squares, diamonds and other suitable shapes. U.S. Patent Application 10/012,918, filed October 30, 2001 and entitled "Boards Comprising an Array of Marks to Facilitate Attachment," cited above, describes various graphics that can be sprayed onto wood boards.

Although the plank 4 can be made of any commonly used material, the plank is preferably made of wood or a wood composite material, and the preferred material for making the plank is OSB board. The method of manufacturing OSB boards and the appropriate composition of OSB boards are known to those skilled in the art.

Those skilled in the art should understand that within the scope of the present invention's broad inventive concepts, various changes can be made to the above-mentioned embodiments, so the present invention cannot be limited to the disclosed specific embodiments, but should be recognized: The invention embraces modifications within its spirit and scope, as defined by the claims.

Claims (12)

1. an equipment that is used for spraying ink marks figure on plank comprises:

Be used to make plank to advance by the device in a predetermined space along a selected direction one by one;

Be used to spray the device of prepared Chinese ink, this ink discharge device can move to its second place away from described predetermined space from its primary importance of pressing close to described predetermined space;

Some runs off the device outside the described predetermined space to be used to detect the plank that moves along described selected direction;

Some just responds described checkout gear moves to described ink discharge device the described second place from described primary importance device when running off described predetermined space to detect the plank of advancing along described selected direction at described monitoring device; And

Be used to control the device of described ink discharge device to the plank spraying ink marks figure of in described predetermined space, advancing.

2. equipment as claimed in claim 1, it is characterized in that the described device that plank is advanced one by one comprises: many driving rolls, manyly can press against the plank of advancing pressing plate roller on the described driving rolls and be connected in the device that described driving rolls can make plank advance along described selected direction with the speed of about 150-600 feet per minute clock by described predetermined space.

3. equipment as claimed in claim 2, it is characterized in that, described ink discharge device comprises: vertical support, carriage that is connected in described vertical support pivotly and an installing plate is arranged, several are contained in the ink gun on the described installing plate, described movement of bracket during to described primary importance described ink gun press close to described predetermined space, described ink gun was about the 0.0625-0.125 inch to the distance by the surface of spraying ink marks figure of described plank when plank was advanced by described space.

4. equipment as claimed in claim 3 is characterized in that, the described device that is used to detect plank can be chosen as disconnect, Laser Devices, sound system or spring.

5. equipment as claimed in claim 3, it is characterized in that, the described device that is used to make the ink discharge device motion comprises that at least one one end is mounted on described carriage and its other end is mounted on the spring of described vertical support, wherein, described at least one spring is in compressive state during in described primary importance in described cradle.

6. equipment as claimed in claim 3, it comprises that also is used to the side direction aligning apparatus that plank is alignd with the lateral edge of scaffold.

7. equipment as claimed in claim 3 is characterized in that described each ink gun is positioned to point to the print direction of a unanimity.

8. equipment as claimed in claim 5 is characterized in that, described carriage can be pivoted to the described second place from described primary importance.

9. equipment as claimed in claim 1 is characterized in that, this equipment also comprises the device of the print surface that is used to handle plank, in order to particle on the print surface of removing plank and electrostatic charge.

10. equipment as claimed in claim 7 is characterized in that, described side direction aligning apparatus comprises a pair of substantially parallel baffle plate mutually.

11. equipment as claimed in claim 1 is characterized in that, this equipment also comprises be used to control the device of described ink discharge device to the plank spraying ink marks figure of advancing in described predetermined space.

12. equipment as claimed in claim 1 is characterized in that, described ink marks figure is formed by prepared Chinese ink, and prepared Chinese ink is the solution that colouring agent and alkyl esters solvent form.

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