Process for recycling waste film and product made therefrom
The present disclosure is directed to a process for recycling film materials, and is particularly directed to collecting spent release liners for labels and constructing new release liner stock from the spent materials. In order to use the waste film, the film is subjected to a process for increasing the intrinsic viscosity. In addition, a coloring agent may be incorporated into the film in order to mask yellowing. In one embodiment, a multilayered composite film is formed.
1. A process for recycling polymer films comprising:
collecting spent liner stock that has been removed from labels, the liner stock comprising a release layer;
reducing the spent liner stock into chips;
solid state polymerizing the liner stock chips in order to increase intrinsic viscosity; and
heating and extruding the liner stock chips into a film.
2. A process as defined in claim 1 , further comprising the step of adding a coloring agent to form a colored film.
3. A process as defined in claim 1 , wherein the spent liner stock comprises a polyethylene terephthalate polymer.
4. A process as defined in claim 2 , wherein the coloring agent comprises a green or blue coloring agent for producing a green colored film.
5. A process as defined in claim 1 , wherein the film has a yellowness index of less than about 1.25.
6. A process as defined in claim 1 , wherein the intrinsic viscosity of the spent liner stock chips is increased to from about 0.58 to about 0.7.
7. A process as defined in claim 1 , wherein the intrinsic viscosity of the spent liner stock chips is increased to from about 0.6 to about 0.64.
8. A process as defined in claim 1 , further comprising the step of laminating the film to a laminate material.
9. A process as defined in claim 8 , wherein the laminate material comprises a label.
10. A process as defined in claim 1 , wherein the extruded film comprises a multilayered film, the multilayered film including at least a middle layer positioned in between a first outer layer and a second outer layer, the liner stock being completely contained within the middle layer.
11. A process as defined in claim 10 , wherein the layers of the film are coextruded.
12. A process as defined in claim 10 , wherein the first outer layer and the second outer layer contain virgin polyethylene terephthalate polymer.
13. A process as defined in claim 12 , wherein the middle layer comprises the liner stock combined with virgin polyethylene terephthalate polymer.
14. A process as defined in claim 2 , wherein the coloring agent comprises a pigment dispersion and is contained within the film in an amount less than about 1% by weight.
15. A process as defined in claim 1 , wherein a release surface is formed on the film by applying a release coating to the film.
16. A process as defined in claim 15 , wherein the release coating comprises a silicone coating.
17. A process as defined in claim 13 , wherein the first outer layer and the second outer layer each comprise from about 5% to about 15% by weight of the coextruded film, the middle layer comprising from about 70% to about 90% by weight of the coextruded film, the middle layer containing the liner stock in an amount of from about 1% to about 100% by weight.
18. A process as defined in claim 1 , further comprising a step of biaxially stretching the film during formation of the film.
19. A process as defined in claim 1 , further comprising the step of pelletizing the spent liner stock prior to increasing the intrinsic viscosity of the liner stock chips.
20. A process as defined in claim 1 , wherein the spent liner stock is collected by a collection device that automatically collects the spent liner stock as labels are removed from the spent liner stock.
21. A process as defined in claim 1 , wherein the spent liner stock is collected without comingling with other waste materials.