Heat-shrinkable polyester film roll

Patent metadata

Field	Value
Publication number	US-11524858-B2
Application number	US-201916964871-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	Jan 31, 2018
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

The invention provides a heat-shrinkable polyester film roll containing a paper tube and a heat-shrinkable polyester film wound around the paper tube to form the heat-shrinkable polyester film roll, wherein (1) the film winding length is 2000-20000 m, (2) the film width is 400-2500 mm, (3) the film thickness is 5-30 μm, (4) unevenness in thickness in the film widthwise direction in a film roll surface layer part is 12% or less, (5) the paper tube has an inner diameter of 3 inches, a difference in clearance of the paper tube in a widthwise direction after removal of the film from the film roll is 0.5 mm or less, and a flat compressive strength of the paper tube after removal of the film is 1700 N/100 mm or more, and (6) the average value of winding hardness in the widthwise direction in the film roll surface layer part is 500-850.

First claim

The invention claimed is:

1. A heat-shrinkable polyester film roll comprising:
a paper tube,
a heat-shrinkable polyester film having a shrinking rate in a main shrinking direction of the film after treated in hot water at 90° C. for 10 seconds of 40% or more, and
the film being wound around the paper tube to form the heat-shrinkable polyester film roll,
wherein the heat-shrinkable polyester film and the film roll satisfy the following requirements (1) to (6):
(1) a film winding length is 2000 m or more and 20000 m or less;
(2) a film width is 400 mm or more and 2500 mm or less;
(3) a film thickness is 5 μm or more and 30 μm or less;
(4) unevenness in thickness in a film widthwise direction in a film roll surface layer part is 12% or less;
(5) the paper tube has an inner diameter of 3 inches, a difference in clearance of the paper tube in a widthwise direction after removal of the film from the film roll is 0.5 mm or less, and a flat compressive strength of the paper tube after removal of the film is 1700 N/100 mm or more; and
(6) an average value of winding hardness in a widthwise direction in the film roll surface layer part is 500 or more and 850 or less.

2. The heat-shrinkable polyester film roll according to claim 1 , wherein a difference in clearance of the paper tube in the widthwise direction before winding the film is 0.3 mm or less.

3. The heat-shrinkable polyester film roll according to claim 2 , wherein unevenness in thickness over the widthwise direction of the film of each sample sampled at intervals of 1000 m of the winding length from the surface layer part of the film roll is 12% or less in all samples.

4. The film roll comprising the heat-shrinkable polyester film according to claim 3 , wherein both of a coefficient of static friction and a coefficient of dynamic friction between winding outside and winding inside of the film are 0.1 or more and 0.8 or less.

5. The film roll comprising the heat-shrinkable polyester film according to claim 2 , wherein both of a coefficient of static friction and a coefficient of dynamic friction between winding outside and winding inside of the film are 0.1 or more and 0.8 or less.

6. The heat-shrinkable polyester film roll according to claim 1 , wherein unevenness in thickness over the widthwise direction of the film of each sample sampled at intervals of 1000 m of the winding length from the surface layer part of the film roll is 12% or less in all samples.

7. The film roll comprising the heat-shrinkable polyester film according to claim 6 , wherein both of a coefficient of static friction and a coefficient of dynamic friction between winding outside and winding inside of the film are 0.1 or more and 0.8 or less.

8. The film roll comprising the heat-shrinkable polyester film according to claim 1 , wherein both of a coefficient of static friction and a coefficient of dynamic friction between winding outside and winding inside of the film are 0.1 or more and 0.8 or less.

Assignees

• Toyo Boseki

Inventors

• Haruta Masayuki
• Tabota Norimi

Classifications

• B29C61/06

  Making preforms having internal stresses, e.g. plastic memory · CPC title

• B29L2007/008

  Wide strips, e.g. films, webs · CPC title

• B29C48/08

  flexible, e.g. films · CPC title

• B65H18/28 Primary

  Wound package of webs · CPC title

• B29C48/0018

  combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence) · CPC title