IP Library Granted Patent US 8,574,694
Granted Patent B2
US 8,574,694 · App. 13/310,034 · Granted Nov 5, 2013

Packaging sheet with improved cutting properties

Inventors: Jesten David Neill (Oshkosh, WI); Curtis Randolph Barr (Neenah, WI); Connie Louise Gherena (Menasha, WI); Dwight Dennis Redding (Appleton, WI)
Assignee: Curwood, Inc.
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Quick Facts
Patent No.
US 8,574,694
App. No.
13/310,034
Granted
Nov 5, 2013
Kind
B2
Abstract

A non-oriented thermoformable packaging sheet having a rigid component layer comprising a blend of an aromatic polyester and a styrenic polymer, where the total amount of styrenic polymer present in the sheet relative to the total weight of the sheet is at least between 3.0% and 4.0% by weight. The packaging sheet has a thickness of at least 5 mil and a normalized impact strength of 0.16 ft*lbf/mil or less total energy as measured in accordance with ASTM D3763-08 test method.

Claims (20)

1. A multilayer non-oriented thermoformable packaging sheet comprising

a first rigid component layer comprising a blend of an amorphous polyethylene terephthalate or glycol-modified polyethylene terephthalate and a general purpose polystyrene;

a second rigid component layer comprising a blend of an amorphous polyethylene terephthalate or glycol-modified polyethylene terephthalate and a general purpose polystyrene;

a coextruded film positioned between and affixed to both the first and second rigid component layers;

wherein the total combined amount of general purpose polystyrene present in the sheet relative to the total weight of the sheet is at least 3% by weight; and

wherein the sheet has a thickness of at least 5 mil and a normalized impact strength of 0.16 ft*lbf/mil or less total energy as measured in accordance with ASTM D3763-08 test method.

2. The packaging sheet of claim 1 wherein the first and second rigid component layers are each an outer layer.

3. The packaging sheet of claim 1 wherein the first rigid component and/or the second rigid component have further layers disposed thereon.

4. The packaging sheet of claim 1 wherein the coextruded film comprises a barrier component.

5. The packaging sheet of claim 4 wherein the barrier component is a layer of ethylene vinyl alcohol copolymer.

6. The packaging sheet of claim 4 wherein the barrier component is a layer of ethylene vinyl alcohol copolymer positioned between two layers of tie material.

7. The packaging sheet of claim 4 wherein the barrier component is a layer of ethylene vinyl alcohol copolymer positioned between two layers of nylon or nylon blend.

8. The packaging sheet of claim 1 wherein the total amount of general purpose polystyrene present in the sheet relative to the total weight of the sheet is between 3.0% and 17% by weight.

9. The packaging sheet of claim 1 wherein the total amount of general purpose polystyrene present in the sheet relative to the total weight of the sheet is between 3.0% and 15% by weight.

10. The packaging sheet of claim 1 wherein the total amount of general purpose polystyrene present in the sheet relative to the total weight of the sheet is between 3.0% and 12% by weight.

11. The packaging sheet of claim 1 wherein the sheet has a thickness of between 5 mil and 15 mil.

12. A package for a product wherein the package comprises the packaging sheet of claim 1 .

13. The package of claim 12 wherein the packaging sheet is thermoformed.

14. The package of claim 12 wherein the packaging sheet is thermoformed into a cup, a tub, a bucket or a tray.

15. The package of claim 12 wherein the product comprises syrup, cream cheese, condiments, personal care item, medication, liquid detergent, oil, pate, pet food, glue, beverage or confections.

Assignments (2)
MERGER AND CHANGE OF NAME Recorded Jul 25, 2017
From: CURWOOD, INC.; BEMIS COMPANY, INC.
To: BEMIS COMPANY, INC.
Reel/Frame 043327/0749 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 29, 2012
From: NEILL, JESTEN DAVID; BARR, CURTIS RANDOLPH; GHERNA, CONNIE LOUISE; REDDING, DWIGHT DENNIS
To: CURWOOD, INC.
Reel/Frame 027781/0878 →
Continuity (2)
Continuation In Part 12611880 · Nov 3, 2009
Related Publication 20120308751A1 · Dec 6, 2012