WO2008073095A1

WO2008073095A1 - Methods and apparatus for screen printing on useful articles

Info

Publication number: WO2008073095A1
Application number: PCT/US2006/047708
Authority: WO
Inventors: Wanson Wu
Original assignee: Robinson, Michelle, Hsiao C.; Zircontec Corp., Corporation Nevada
Priority date: 2006-12-13
Filing date: 2006-12-13
Publication date: 2008-06-19

Abstract

The.invention' is for methods and the apparatus, used for transferring images onto the useful articles, such as a computer laptop cover. Methods of the invention include forming a mold of the article on a sheet of mesh or release agent, silk-screen layering of ink to colorize the design, then gluing the design to the useful article. In another embodiment the design sheet is made without a mold and affixed to the useful article by shrink wrapping it over the useful article in a vacuum chamber.

Description

METHODS AND APPARTUS FOR SCREEN PRINTING ON USEFUL ARTICLES

Wanson Wu Related Applications This application hereby incorporates by^' reference and claims the priority and filing date of U.S. provisional patent application serial number 60/750,295, Wanson Wu inventor, filed 12/13/2005 and entitled METHOD AND APPARTUS FOR SCREEN PRINTING ON USEFUL ARTICLES.

Copyright Notice

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The^' copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent, and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

Field of the Invention

This invention relates to screen printing on products and to advertising methods. This invention relates more particularly to methods for applying a decorative image to a polyvinyl chloride type of substrate on articles such as computer covers and using that image to advertise a product, individual, group or institution.

Background of the Invention In the past the exterior of products such as computer cases such as that of a laptop computer have been decorated by forming three-dimensional designs in the case of the computer itself. These designs may be painted or dyed. In the past it has been difficult to transfer images or dyes directly onto plastic items such as Acrylonitrile-Butadiene-Styrene (ABS) product housings. The temperatures required for transferring images and dyes to such a surface were high enough to cause the housing itself to melt.

SUMMARY OF THE INVENTION The present invention presents methods for transferring images onto the useful articles, such as laptop covers, with alternative embodiments of the methods selected for different materials of the useful articles to which the image need be applied. One of the methods of the present invention is most suitable for use with image transfer sheeting material made of a Polyvinyl chloride (PVC) plastic sheet.

In one embodiment of the present invention transfer a module plate comprised of a replica of a useful article to be decorated is first formed. A release agent is first applied to the module and an impression of the useful article design is taken- When the release agent is allowed to cool to about 4OC the design is removed from the module plate. Several layers akin to silk screening are then are applied onto the release agent on the module plate to form a design on the module template. For a colored finished product subtractive coloring is used by mixing pigments of primary colors in order to make other colors, using cyan, yellow, magenta, and black inks. A first primary color coating of the image is applied over the release agent and allowed to dry, then a second primary color is applied over the first primary coat in a similar fashion and allowed to dry, the a third primary coat applied over the second primary coat and allowed to dry, providing all three primary subtractive colors of the image. A fifth white coat may then applied over the image to increase color contrast, concentration and brightness of the image. A final heat- resistant clear protective coating may be applied over the white coat. .The image sheet is then affixed to the useful object with a heated adhesive to achieve a sure bond with the useful object.

In another embodiment of a method of the present invention an image transfer sheet is created but without using a module plate. In this method a release agent is applied to mesh sheeting and then layered with in a similar fashion of layering as used in the first embodiment. A spreading machine ink is used in this method with a computer digital image or painted art work projected onto the PVC image transfer sheet using the mirror printing technique, know to those of skill in the art.

The image sheet is transferred to a useful object in a vacuum pressure transfer machine chamber to shrink wrap the image sheet onto the article. The image transfer sheet is first wrapped around the object, and pressure and vacuum are then applied. Adhesive is then applied to the image transfer sheet and further pressed onto the useful article. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic, side view of color layering of one embodiment of the present invention. Figure 2 is a schematic, side view of color layering of another embodiment of the present invention.

Figure 3 is a photograph of a laptop computer cover decorated by a method of the present invention.

Figure 4 is a schematic side view of apparatus of a vacuum pressure low temperature transfer of images.

Figure 5 is flow chart diagram of the methods of the present invention.

DESCRIPTION OF THE INVENTION The following description, and the figures to which it refers, are provided for the purpose of describing examples and specific embodiments of the invention only and are not intended to exhaustively describe all possible examples and embodiments of the invention. The method of the present invention is most suitable for use with image transfer sheeting material made of a Polyvinyl chloride (PVC) plastic sheet. This method may not be as effective when used with Polyethylene Teraphthalate (PET) types of sheeting. PVC image transfer sheeting allows the sheet to transfer an image smoothly to curves and angles on an object, such as the cover of a laptop computer. Laptop computer covers are typically made of ABS, Polycarbonate (PC) and an alloy or combination of ABS and PC, they are compatible with use- of PVC image transfer sheeting for the processes of the present invention.

Referring now to figure 1, in one embodiment of the present invention transfer printing is used _.with a PVC module plate 10 comprised of a replica of a useful article to be decorated. The module plate 10 of the replica is preferably made of a PVC mesh plastic sheet, of about 250 Mesh. Other plastic material having a suitably high melting point might be used as well. The module plate 10 replica is of the shape and size of the useful article. The module plate 10 can be formed by methods that will be appreciated by those of skill in the art, using a exemplary useful article as a mold.

The module plate 10 must be used with material such as PVC, it would be too hot to be used in CNC aluminum metal mode or treated wood mode. CNC aluminum has too low a melting point and would warp at too low a temperature. Treated wood is of too low a density and could damage the transformation object, the completed image sheet 24.

In the method of the present invention an ink container and color spread gun is used to enable a colored ink supply to be used to print the image.

A release agent 12 is first applied to the module 10. The release agent 12 used should first be diluted if needed to an appropriate viscosity to allow spraying and to prevent the finished design from later sticking to the surface of the module plate 12. The release agent 12 should also be applied evenly over the module plate 10 to prevent the finished design from later sticking to the surface of the module plate 10. The release agent 12 should be allowed to cool to about 4OC before the design is removed from the module plate 10.

Several layers then are applied onto the release agent 12 on the module plate 10 to form a design. The design is generated by a digital image according the methods used in screen printing techniques.

In most applications a user will desire the use of coloring of the useful article as shown in figure 1. YMCK is a subtractive color model used in color printing based on mixing pigments of primary colors in order to make other colors, Cyan, Yellow, Magenta, Cyan and a key color, black. The mixture of ideal- CMY colors is subtractive, YMCK works through light absorption, the colors that are seen by a^' viewer are from the part of light spectrum that is not absorbed. In YMCK magenta plus yellow produces red, magenta plus cyan makes blue, cyan plus yellow generates green and the combination of cyan, magenta, and yellow form black. After the release agent 12 has been applied a first primary color coating 14 of the image is applied over the release agent, with a minimum at 400Mesh or higher. This is because most color inks currently used cannot penetrate beyond 300-350Mesh and use of a higher mesh is required to prevent an uneven color print. After the first primary color is applied it should be allowed to dry.

A second primary color 16 is applied over the first primary coat in a similar fashion and allowed to dry. A third primary coat 18 is applied over the second primary coat 16 and allowed to dry, providing all three primary subtractive colors of the image. Care should be taken to allow the individual coatings to cool between coatings and keep them near room temperature because otherwise the PVC module plate 10 could shrink or expand with high heat, ruining the image with this distortion.

A fifth white coat 21 is then applied over the image to increase color contrast, concentration and brightness of the image. The white coat 20 typically uses ink that requires a 300Mesh screen.

A final heat resistant clear protective coating 22 is applied over the white coat 21. The clear coating 22 used is determined by the composition of the useful article to which the design will be affixed, ABS, PC, or an ABS/PC alloy for example. If the article is made of an ABC/PC alloy the preferred heat for transferring the image is 75-90C. The protective coating 22 then must be matched to have a higher melting point or be able to withstand the preferred heat for a given material without degrading. Together these layers comprise an image sheet 24.

The image sheet 24 is affixed to the useful object with a heated adhesive to achieve a sure bond with the useful object. For example where the image sheet transfer is designed to be a laptop computer cover 26 having an uneven surface and curves, the image 24 will be securely bonded to that cover, making it resistant to alcohol and other chemicals, as shown in figure 3. To achieve this the adhesive used should preferably be heated to a high enough temperature to actually bond with the ink itself.

Referring further to figure 2 in another embodiment of the present invention an image transfer is achieved without a module plate 10. In this method a release agent 32 is applied to 250Mesh PVC sheeting 30 in a similar fashion of layering as used in the first embodiment. An image transfer sheet 40 will look much like the transfer sheet 24 shown transferred to a laptop computer cover 26 in figure 3.

A release agent 32 is first applied, to the PVC sheet 30. The release agent 32 used should first be diluted if needed to an appropriate viscosity to allow spraying and to prevent the finished design from later sticking to the surface of the PVC sheet 30. The release agent 32 should likewise also be applied evenly over the PVC sheet 30 to prevent the finished design from later sticking to the surface of the module plate 10. Again the release agent 32 should be allowed to cool to about 40⁰C before the design is removed from PVC sheet 30. Protective oil is applied when the image is eventually peeled from the PVC.

A spreading machine ink is used in this method. A computer digital image or painted art work is projected onto the PVC sheet 30 using the mirror printing technique know to those of skill in the art. The ink used is an oil dye, which has not been used much in these applications in the past, to print images on a PVC cover. A clear oil 34 is applied to the release agent 32, the clear oil must be heat resistant enough to not melt and degrade under the heat used in the process when applying the resulting image to^* the useful article, for example the laptop cover. The full color printing spread machine is used to imprint the fully-colored image 35 onto the clear oil layer 34.

As in the first embodiment, a white coat 36 is then applied over the image to increase color contrast, concentration and brightness of the image. The white coat 36 typically uses ink that requires a 300Mesh screen.

A final heat resistant clear protective coating 38 is applied over the white coat 36. The clear coating 38 used is determined by the composition of the useful article to which the design will be affixed, ABS, PC, or an ABS/PC alloy for example. If the article is made of an ABC/PC alloy the preferred heat for transferring the image is 75-90⁰C. The protective coating 38 then must be matched to have a higher melting point or be able to withstand the preferred heat for a given material without degrading. Together these layers comprise an image sheet 40.

The image sheet 40 is affixed to the useful object with a heated adhesive to achieve a sure bond with the useful object. For example where the image sheet transfer is designed to be a laptop computer cover having an uneven surface or curves, the image will be securely bonded to that cover, making it resistance to alcohol and other chemicals. To achieve this the adhesive used should preferably be heated to a high enough temperature to actually bond with the ink itself. It is good practice to obtain the clear coating from the same manufacturer as the one providing the PVC 250Mesh sheet to insure chemical compatibility.

Referring further to. figure 4, the image is transferred to a useful object in the second embodiment by a low temperature image transfer method where a temperature below 75-9O⁰C is maintained to prevent the plastic useful article from warping, here by way of example a laptop cover 26 made of ABS, PC, or an ABS/PC alloy. This is why a low temperature release agent is needed.

The image sheet 40 is transferred using an adhesive 42 in a vacuum pressure transfer machine 50 to shrink wrap the image sheet onto the article. The adhesive is applied to the image sheet 40 and place in the transfer machine 50. With the use of vacuum pressure and mild heat in pressure transfer machine, the PVC sheet 40 becomes transferred to the surface of the laptop cover. This method there allows a transfer of the image without the use of damaging heat or pressure on the image sheet 40.

The vacuum causes the PVC sheet to wrap around the useful article even where there is an uneven surface or curves in the object. Pressure is also applied together with the vacuum to achieve a secure wrapping of the image sheet 40. The preferred sequence of achieved a good bonding of the two objects are: a. The image transfer sheet 40 is first wrapped around the object, here a laptop computer cover. Pressure and vacuum are then applied. b. Adhesive is then applied to the image transfer sheet 40 and further pressed onto the useful article. The adhesive is heated to about 90C and care should be taken to maintain this temperature between the adhesive and the useful article during transfer of the image to insure a good bonding. Heating the adhesive or the useful art to temperatures much above this point however can melt the useful article. The plastic used for many useful articles, such as laptop covers, is ABS, PC, or an ABS/PC alloy, have lower melting points that might otherwise be reached. Were this to occur the useful article might warp and be damaged.

The proper selection of which of the two methods should properly be used for various materials is summarized in the following tables 1 and 2:

Table 1

Table 2

A flow chart diagram of the methods of the present invention is shown in figure 5.

It will be appreciated that the invention has been described hereabove with reference to certain examples or preferred embodiments as shown in the drawings. Various additions, deletions, changes and alterations may be made to the above-described embodiments and examples without departing from the intended spirit and scope of this invention.

Accordingly, it is intended that all such additions, deletions, changes and alterations be included within the scope of the following claims.

Claims

CIAIMS

What is claimed is:

1) A method for creating an image on a useful article, comprising the steps of: providing a module plate and coating a side with a release agent, making an impression with the module on a useful article to over the release agent to create a replica of the useful article, removing the module from the useful article, coating the release agent with one or more layers of ink with silk screening techniques for a design, coating the one or more layers with a white coat to increase color contrast, concentration and brightness of the image, coating the white coat with a heat-resistant clear protective coating, and affixing the coated release agent to the useful article an adhesive.

2) A method for creating, an image on a useful article, comprising the steps of: providing an mesh image transfer sheet with a design on it, coating the image transfer sheet with a release agent, coating the release agent with one or more layers of ink, transferring the image transfer sheet to a useful article in a vacuum pressure chamber to shrink wrap the image sheet onto the article, and applying an adhesive and pressing the image transfer sheet onto the useful article.