High-slip stretch film

Patent metadata

Field	Value
Publication number	US-11446909-B2
Application number	US-201816222213-A
Country	US
Kind code	B2
Filing date	Dec 17, 2018
Priority date	Mar 14, 2013
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A multi-layer stretch wrap film has three or more layers, including at least one outer non-cling layer, at least one inner core layer, and at least one outer cling layer, where the film displays enhanced non-cling properties after being stretched.

First claim

The invention claimed is:

1. A multilayer stretch film comprising
a non-cling layer comprising (i) 50-99% by weight of the layer of a polyethylene blend comprising low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) and (ii) polystyrene,
a core layer comprising at least one polyolefin, and
a cling layer comprising ultra-low density polyethylene, very low density polyethylene, polyisobutylene, linear low density polyethylene, or mixtures thereof,
wherein the non-cling layer is more slippery when the multilayer stretch film is in a stretched state compared to the non-cling layer when the multilayer stretch film is in an unstretched state.

2. The multilayer stretch film of claim 1 , wherein the non-cling layer comprises 10-30% by weight of the non-cling layer of LLDPE.

3. The multilayer stretch film of claim 2 , wherein the polystyrene is present in the non-cling layer at about 1% to about 25% by weight of the non-cling layer.

4. The multilayer stretch film of claim 3 , wherein the non-cling layer comprises about 10% to about 25% by weight of the non-cling layer of polystyrene.

5. The multilayer stretch film of claim 1 , wherein the non-cling layer comprises about 10% by weight of the non-cling layer of polystyrene.

6. The multilayer stretch film of claim 5 , wherein the non-cling layer comprises about 0.1% to about 1.5% by weight of additives based on the weight of the non-cling layer.

7. The multilayer stretch film of claim 1 , wherein the multilayer stretch film has a thickness of about 0.4 mils to about 5 mils.

8. The multilayer stretch film of claim 7 , wherein the thickness is about 2.5 mils to about 5 mils.

9. The multilayer stretch film of claim 8 , wherein the thickness is about 3 mils to about 5 mils.

10. The multilayer stretch film of claim 7 , wherein a stretching force of greater than about 200 pounds is applied to the multilayer stretch film to elongate the multilayer stretch film from the unstretched state to the stretched state.

11. The multilayer stretch film of claim 1 , wherein the non-cling layer is about 5%-40% by weight of the film.

12. The multilayer stretch film of claim 11 , wherein the core layer is about 50%-90% by weight of the film.

13. The multilayer stretch film of claim 12 , wherein the cling layer is about 5%-40% by weight of the film.

14. The multilayer stretch film of claim 13 , wherein the core layer comprises about 97% to about 100% by weight of the core layer of LLDPE linear low density polyethylene.

15. The multilayer stretch film of claim 14 , wherein a thickness of the multilayer stretch film is about 2.5 mils to about 5.0 mils, wherein a stretching force of greater than about 200 pounds is applied to the multilayer stretch film to elongate the multilayer stretch film from the unstretched state to the stretched state, wherein the non-cling layer comprises about 2.5% to about 25% by weight of the non-cling layer of polystyrene, and the polyethylene blend of the non-cling layer comprises about 10% to about 30% by weight of the non-cling layer of LLDPE.

16. A multilayer stretch film comprising
a non-cling layer comprising polyethylene and polystyrene,
a core layer comprising at least one polyolefin, and
a cling layer comprising ultra-low density polyethylene, very low density polyethylene, polyisobutylene, linear low density polyethylene, or mixtures thereof,
wherein the non-cling layer is more slippery when the multilayer stretch film is in a stretched state compared to the non-cling layer when the multilayer stretch film is in an unstretched state, and
wherein the non-cling layer is free of polypropylene.

17. The multilayer stretch film of claim 16 , wherein the polyethylene of the non-cling layer is a blend comprising LDPE and LLDPE.

18. A multilayer stretch film comprising
a non-cling layer comprising 50-99% by weight polyethylene and 1-25% by weight polystyrene, based on the weight of the non-cling layer,
a core layer comprising at least one polyolefin, and
a cling layer comprising ultra-low density polyethylene, very low density polyethylene, polyisobutylene, linear low density polyethylene, or mixtures thereof,
wherein the non-cling layer is more slippery when the multilayer stretch film is in a stretched state compared to the non-cling layer when the multilayer stretch film is in an unstretched state.

19. The multilayer stretch film of claim 18 , wherein the polyethylene of the non-cling layer is a blend comprising LDPE and LLDPE.

Assignees

• Berry Plastics Corp

Inventors

• Kinnan Michael A
• Kitzmiller Brooke D

Classifications

• B32B2270/00

  Resin or rubber layer containing a blend of at least two different polymers · CPC title

• B32B2307/554

  Wear resistance · CPC title

• B32B2553/02

  Shock absorbing · CPC title

• B65D19/44

  Elements or devices for locating articles on platforms · CPC title

• B32B2250/05

  5 or more layers · CPC title