Method for creating full color heat activated transfers

The present disclosure provides a method for transferring an image to a substrate that includes providing a transfer medium having at least one registration mark; printing an image on the transfer medium; covering the image with a backing layer, the backing layer not covering the registration mark; covering the backing layer with an adhesive layer; penetrating the adhesive layer and the backing layer with a cutting device at locations around the image, the penetrating of the adhesive layer and backing layer not penetrating the transfer medium; removing portions of the adhesive layer and backing layer from the locations around the image; and transferring the image to the substrate.

FIELD

The present disclosure relates to a method for creating full color heat activated transfers.

BACKGROUND

Screen printing is a printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed.

Screen printing can also be a stencil method of print making in which a design is imposed on a screen of polyester or other fine mesh, with blank areas coated with an impermeable substance. Ink is forced into the mesh openings by the fill blade or squeegee and by wetting the substrate, transferred onto the printing surface during the squeegee stroke. As the screen rebounds away from the substrate the ink remains on the substrate. It is also known as silk-screen, screen, serigraphy, and serigraph printing. One color is printed at a time, so several screens can be used to produce a multicolored image or design. Such a process, however, is time-consuming and costly due to the use of multiple screens that are needed for multicolor images.

SUMMARY

The present disclosure provides a method for transferring an image to a substrate that includes providing a transfer medium having at least one registration mark; printing an image on the transfer medium; covering the image with a backing layer, the backing layer not covering the registration mark; covering the backing layer with an adhesive layer; penetrating the adhesive layer and the backing layer with a cutting device at locations around the image, the penetrating of the adhesive layer and backing layer not penetrating the transfer medium; removing portions of the adhesive layer and backing layer from the locations around the image; and transferring the image to the substrate.

DETAILED DESCRIPTION

FIG. 1illustrates a transfer medium or release film10having a plurality of images12printed thereon. Images12may be formed on release film10using any method known to one skilled in the art. A preferable method of forming images12on release film10is an ink jet printing method that provides a high degree of detail and accuracy when printing the images12. It should be understood, however, that other known methods of printing the images such as bubble jet methods, toner printing methods, roller printing methods, and the like are contemplated. Images12can be printed in a mirror-image, or be printed normally.

Release film10may be formed from a transparent material, but the present disclosure should not be limited thereto. Materials that may be used to form release film include polymeric materials such as polyvinyl chloride materials, polyethylene, polypropylene, polyvinyl alcohol, and other materials known to one skilled in the art. The release film10may additionally include an ink-receiving layer (not shown) that has various properties to prevent bleeding of the inks, or is formed of a material that reacts with various components of the inks such as surfactants, solvents, pigments, dyes, polymer particles (if any), and the like.

There is no limitation on the type of ink that may be used to form images12. In this regard, the inks used to form images12may be aqueous inks, or solvent-based inks that do not substantially contain water. In addition, the inks selected to form images12may include color materials that are pigment-based, or dye-based. If a pigment-based ink is selected, it is contemplated that the inks may include a metallic pigment. Moreover, as noted above, the inks may include various surfactants, solvents, polymer particles, and the like as are known to one skilled in the art.

As illustrated inFIG. 1, release film10includes a plurality of registration marks14. Registration marks14may be printed along with images12. Alternatively, registration marks14may be apertures formed in release film10before or after forming images12. Registration marks14are used to align a cutting device (not shown) that is used in a subsequent step of the method according to the present disclosure, as will be described in more detail later.

After forming images12and registration marks14, a backing layer16is formed on release film10over the images12. As best shown inFIG. 2, backing layer16is formed over a majority of the surface18of release film10, with the exception of registration marks14. Backing layer16may be formed by the above-noted ink jet process using an opaque ink such as a plastisol, which is a suspension of PVC particles in a liquid plasticizer. Alternatively, backing layer16may be formed using a roller or gravure coating device, or by using a screen printing process. A screen printing process can be used because no special configuration is required for the screen to form the backing layer16.

Backing layer16, although preferably opaque, should not be limited thereto. In this regard, backing layer16may be transparent or at least semi-transparent without departing from the scope of the present disclosure. Backing layer16serves as a layer that, when the image12is finally transferred to a substrate (not shown) such as fabric or some other type of substrate, will be located between the image12and the substrate. Backing layer16, therefore, may assist in adhering the image12to the substrate after the image12has been transferred to the substrate.

Now referring toFIG. 3, it can be seen that after forming backing layer16over the image12formed on the release film10, an adhesive layer20is formed over the backing layer16. In one embodiment, adhesive layer20may be formed from a powder adhesive that is sprinkled over backing layer16. Alternatively, release film10including the image12and backing layer16may be placed in a tray containing the powder adhesive and submerged in the powder adhesive. Regardless, the powder adhesive that will form adhesive layer20adheres to the backing layer16. Backing layer16, therefore, should be in a semi-liquid or gel-like state to ensure that the powder adhesive adheres to the backing layer16. Further, it is important to note that registration marks14are not covered by adhesive layer20so that registration marks14are not obscured in any way. Any type of powder adhesive known to one skilled in the art may be used. Exemplary powder adhesives include copolyamides and copolyesters. The present disclosure, however, should not be limited to these materials.

In another embodiment, adhesive layer20may be formed over backing layer16using a liquid adhesive. Liquid adhesives are well known in the art of image transfer, and any known liquid adhesive may be used to form adhesive layer20. Liquid adhesive can be deposited onto backing layer16using a screen printing method in a manner similar to forming backing layer16, an ink jet method, a roller method, a gravure method, or any other method known to one skilled in the art. If adhesive layer20is formed using a liquid adhesive, it should be understood that backing layer16should be substantially dry to the touch before adhesive layer20is provided thereon.

In yet another embodiment, adhesive layer20may be in the form of an adhesive sheet that is adhered to backing layer16. The adhesive sheet (not shown) can include a pressure-sensitive adhesive and/or a heat-sensitive adhesive. In this regard, one side of the adhesive sheet can include a pressure-sensitive adhesive that is adhered to backing layer16by pressing, and an opposing side of adhesive sheet can include a heat-sensitive adhesive that adheres the adhesive layer20to the final substrate (not shown) using heat and pressure.

Now referring toFIG. 4, it can be seen that the release film10is ready for cutting. In this regard, in one embodiment, a die cutting device (not shown) having dies that correspond to each of the plurality of images12may be used to “kiss cut” through the adhesive layer20and backing layer16without penetrating the release film10. Kiss Cutting is a form of die cutting where a very light impression of the dies cuts through various layer(s), without penetrating one or more bottom-most layers. The die cutting device is designed and shaped such that when the die cutting device is aligned with registration marks14, the dies will correctly correspond to each of the plurality of images12so that the dies can be used to penetrate the adhesive layer20and backing layer16, without disturbing the images12. The die cutting device may also include dies that cut off the regions22of the release film10that includes the registration marks14.

It should also be understood that a die cutting device having dies that correspond to the shapes of the images12is not necessarily used. In this regard, in another embodiment, a cutting tool or blade (not shown) that is programmed to cut around each of the images12may be used. Such a cutting tool omits the need for individual dies being manufactured that correspond to each image12.

Further, in yet another embodiment, a laser cutting device (now shown) may be used to cut through the adhesive layer20and backing layer16without penetrating the release film. The laser cutting device can be configured to “cut” through different depths by adjusting an intensity of the laser, or altering the speed at which the laser cutting device is translated about the image during the cutting process.

Now referring toFIG. 5, it can be seen that after subjecting the release film10to cutting using any of the above-noted methods (i.e., die-cutting, tool cutting, or laser cutting), the backing layer16and adhesive layer20surrounding each image12are removed. The images12containing the remaining portions of the backing layer16and adhesive layer20are now ready for transfer to the final substrate upon which the images12will be transferred. Before transferring the images12to the final substrate, the release film10may be cut at locations between the images12such that individual images12may be transferred to respective final substrates, as desired.

Lastly, the images12including the backing layer16and adhesive layer20may be transferred to the final substrate. To transfer the images12, the images12are placed on the final substrate such that the adhesive layer20contacts the final substrate. Then, heat and pressure are applied to the images12. The heat and pressure may be applied to the image12in a direction from underneath the final substrate, or the heat and pressure may be applied to the image12in a direction from over the release film10. After sufficient heat and pressure is applied to ensure satisfactory transfer of the image12to the final substrate, the release film10may be peeled away from the image12.

The above method is superior to previous image transfer processes such as digital printing because there is no need to used rolled printable media. In contrast, individual sheets of release films can be used, which reduces manufacturing costs. In addition, the method of the present disclosure omits the need for applying a mask that surrounds each of the images12. This also reduces manufacturing costs because the materials associated with the mask, and the steps associated with using a mask, are omitted. Moreover, the above method is superior to screen printing because there is no need to manufacture a separate screen for each image that is to be transferred. Lastly, because the images12are formed using, for example, an ink jet printing process, the number and types of images that may be printed is substantially increased. Further, ink jet printing allows for different colors, gradients, and different effects to be printed that are not possible using a conventional screen printing process.