Patent Application
20080053608
A pre-printed rigid thermoformable material or sandwich fabricated in accordance with the current embodiment of the invention is illustrated in
Each of the rigid thermoformable films 12 and 14 can be any of a wide variety of materials known to those skilled in the art. In the current embodiment, each film is a polyvinylchloride (PVC) material. Other suitable materials include, but are not limited to, polyethylene terephthalate glycol (PETG), amorphous polyethylene terephthalate (APET), recycled polyethylene terephthalate (RPET), polypropylene (PP), or oriented polystyrene (OPS).
In the current embodiment, each film is approximately 8 mils (0.008 inch) thick. Other suitable thicknesses may be used, and the thickness will depend on the material, the ultimate packaging application, and other considerations. It is anticipated that materials up to 30 mils thick could be handled and printed on currently available printing equipment. In the current embodiment, the two films 12 and 14 each have a uniform thickness. However, such uniformity is not required. The layers may be of different thicknesses depending on the particular application and considerations in the subsequent thermoforming operation. If the layers are of different thicknesses, the printing 18 typically would be applied to the thinner layer because the thinner layer typically can be more easily printed. However, the printing as noted above may be included on any or all of the four surfaces of the two films.
Currently, at least one of the films is transparent or translucent so that the printing 18 may be viewed through that film. The degree of opacity and/or transparency of the films 12 and 14 will depend, among other factors, on the desired visual effect in combination with the printing 18.
The printing 18 is included on the inside surface 20 of the upper film 12. The printing can be any suitable process known to those skilled in the art. Suitable processes include, but are not limited to, gravure, flexo, digital, screen, and offset. The printing 18 preferably is sufficiently flexible so that, when the sandwich 10 is subsequently thermoformed, the printing will not chip or crack.
Although the printing 18 is illustrated as being on the inside surface 20 of the top film 12, additional printing may be on any or all of (a) the two surfaces of the upper film 12 and (b) the two surfaces of the lower film 14. When the printing is located on one of the facing inside surfaces 20 or 22, then the printing will be protected from scratching or marring during subsequent handling and thermoforming.
The printing 18 as illustrated in
The two film layers 12 and 14 are adhered together by a laminated adhesive 24. Presently, the laminating adhesive is a solvent-based urethane. Alternative adhesives will be known to those in the art and will depend on the particular material or materials of which the rigid thermoformable films 12 and 14 are fabricated. For example, one currently anticipated alternative adhesive is the solvent-based adhesive sold under the trademark PERMUTHANE™ by Stahl. Other currently anticipated alternative adhesives include gravure laminating adhesives, ultraviolet (UV) laminating adhesives, and electronic beam (EB) adhesives.
Suitable manufacturing techniques for producing the sandwich 10 are known to those in the art. Typically, the films 12 and 14 are continuous webs and the resulting sandwich 10 also is a continuous web. Alternatively, the sandwich 10 can be fabricated in sheet form, in which case the beginning films 12 and 14 could be either continuous or sheet form themselves. Printing 18 is applied to the desired surfaces of the films 12 and 14. Any printing on the facing inside layers 20 and 22 is applied before the films are adhered together. Printing on the exposed surfaces may be applied either before or after the films are adhered together.
The material 10 is used in subsequent thermoforming operations, which do not form part of the present invention, to produce packaging article for consumer or other products. One exemplary article 30 is illustrated in
The above description is that of a current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in appended claims, which are to be interpreted in accordance with the principles of patent law, including the doctrine of equivalents.
