Tube and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-10953587-B2
Application number	US-201916352233-A
Country	US
Kind code	B2
Filing date	Mar 13, 2019
Priority date	Mar 30, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Provided are a tube that has high inner-surface smoothness and outer-surface smoothness and a thickness distribution with a small variation, and a method for manufacturing the tube. The tube includes points a, b, c, and d that satisfy the following conditions (1) and (2): (1) 0.9<Rea/Rec<1.1 and 0.9<Reb/Red<1.1; and (2) Rea/Reb≤0.9 or Rea/Reb≥1.1. The points a, b, c, and d are four random points that are located on the circumference of the tube on any cross section in the axial direction of the tube, and are aligned in the stated order in a circumferential direction. Rea, Reb, Rec, and Red respectively indicate retardations at the points a, b, c, and d. The tube satisfies the following condition (3): (3) (10-point standard deviation/10-point average)×100≤2 in the respective sets A, B, C, and D. Each of the sets A, B, C, and D includes retardations at ten random points present in a range between the point a, b, c, or d and a point 5 mm away from that point in the axial direction.

First claim

What is claimed is:

1. A tube made of a fluororesin,
the tube having axial tearability and heat-shrinkable properties,
the tube including points a, b, c, and d that satisfy both conditions (1) and (2) below:
0.9<Rea/Rec<1.1 and 0.9<Reb/Red<1.1; and   (1)

Rea/Reb≤0.9 or Rea/Reb≥1.1,   (2)

the points a, b, c, and d being four random points that are located on a circumference of the tube on any cross section in an axial direction of the tube, and being aligned in the stated order in a circumferential direction,
the Rea, Reb, Rec, and Red respectively indicating retardations at the points a, b, c, and d,
the tube further satisfying a condition (3) below:
(10-point standard deviation/10-point average)×100≤2 in respective sets A, B, C , and D, and   (3)

each of the sets A, B, C, and D including retardations at ten random points present in a range between the point a, b, c, or d and a point 5 mm away from that point in the axial direction.

2. The tube according to claim 1 , wherein a surface roughness Rz of an outer surface of the tube is 2.0 μm or less.

3. The tube according to claim 1 , wherein a surface roughness Ra of an outer surface of the tube is 1.0 μm or less.

4. The tube according to claim 1 , wherein a distance between the points a and b is shorter than a quarter of a circumferential length of the tube.

5. The tube according to claim 1 , wherein a distance between the points a and b is 0.4 mm or shorter.

6. The tube according to claim 1 , wherein the fluororesin can be molded through heat-melting extrusion molding.

7. The tube according to claim 1 , wherein the fluororesin is a multi-component copolymer comprising constituted by three or more types of monomers.

Assignees

• Gunze Kk

Inventors

• Kobayashi Daiki
• Oshima Hiroshi
• Sekiya Kazutaka

Classifications

• B29K2995/0081

  Tear strength · CPC title

• A61J15/0003

  Nasal or oral feeding-tubes, e.g. tube entering body through nose or mouth · CPC title

• B29C48/09

  Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels · CPC title

• F16L9/12

  of plastics with or without reinforcement (F16L9/16 - F16L9/22 take precedence) · CPC title

• F16L11/06 Primary

  with homogeneous wall (F16L11/11 takes precedence) · CPC title