Granted Patent B2

US 11,931,229 · App. 16/384,295 · Granted Mar 19, 2024

Inventors: Leopoldo V. Cancio (Vero Beach, FL); Frank Eschenbacher (Schnelldorf, DE); Jerry Ford (Maineville, OH)

Assignee: Berry Film Products Company, Inc.

A61F13/15707A61F13/15699A61F13/51401A61F13/51462A61F13/51478B29C48/08B32B27/12B32B27/20B32B27/205B32B27/32C08J5/18A61F2013/15292A61F2013/15406A61F2013/15544A61F2013/15715A61F2013/51431B29K2023/04B29K2023/10B29K2101/12B29L2007/008B32B2264/104B32B2270/00B32B2305/026B32B2307/514B32B2555/00B32B2555/02C08J2323/06C08J2323/08C08J2323/12C08J2423/12Y10T428/27

Abstract

Claims (26)

1. A method of making a thermoplastic film product is provided, comprising

extruding a molten web comprising a thermoplastic polymer from an extruder onto a first chill roller, said first chill roller operating at a peripheral velocity V1 and at a temperature T1, wherein the temperature T1 is from about 80° C. to about 160° C., which is below the melting point of the thermoplastic polymer and which cools said molten web to form a film;

advancing the film to a first stretching roller which operates at a peripheral velocity V2 which is greater than the peripheral velocity V1, and at a temperature T2;

advancing the film to a first machine direction orientation section comprising at least one heated roller having a temperature T3 and a second stretching roller; and

stretching the film in the first machine direction orientation section in the machine direction to produce a film having limited machine direction orientation and a ratio of the MD load at break to a CD load at break of less than about 10,

wherein the first chill roller and the first stretching roller are separated by a distance, wherein the distance is at least about 7.5 cm.

2. The method of claim 1 , wherein the ratio of the MD load at break to the CD load at break is about 8.

3. The method of claim 1 , wherein the ratio of the MD load at break to the CD load at break is about 5.

4. The method of claim 1 , wherein the molten web is cast, blown, mono-extruded, co-extruded, or combinations thereof.

5. The method of claim 1 , further comprising the step of advancing the film onto at least one additional chill roller operating at a temperature T and a peripheral velocity V.

6. The method of claim 1 , further comprising the step of stretching the film in the cross-direction.

7. The method of claim 6 , wherein the film has a water vapor transmission rate of at least about 500 grams—H 2 O/24-hour/m 2 .

8. The method of claim 6 , wherein the film is stretched in the cross-direction using interdigitated rollers.

9. The method of claim 1 , wherein the film is advanced through at least a second machine direction orientation section comprising at least one additional heated roller and at least one additional stretching roller.

10. The method of claim 9 , wherein the second machine direction orientation section is located downstream from a cross direction interdigitated roller section.

11. The method of claim 9 , wherein the second machine direction orientation section is located upstream from a cross direction interdigitated roller section.

12. The method of claim 1 , wherein the temperature T1 is from about 100° C. to about 160° C.

13. The method of claim 1 , wherein the temperature T2 is from about 60° C. to about 100° C.

14. The method of claim 1 , wherein the temperature T3 is from about 80° C. to about 150° C.

15. The method of claim 1 , wherein the film has a basis weight of about 15 gsm or less.

16. The method of claim 1 , wherein the film has a basis weight of from about 5 gsm to about 15 gsm.

17. The method of claim 1 , wherein the film has a basis weight of from about 8 gsm to about 13 gsm.

18. The method of claim 1 , wherein the film has a machine-direction notched Elmendorf tear strength of at least about 5 g.

19. The method of claim 1 , wherein the film has a machine-direction notched trapezoidal tear strength of at least about 15 g.

20. The method of claim 1 , wherein the thermoplastic polymer is an olefin block copolymer, an ethylene-based polymer, a propylene-based polymer, or combinations thereof.

21. The method of claim 1 , wherein the distance is from about 7.5 to about 30 cm.

Assignments (36)

Continuity (7)