Blow-molded foam and process for producing the same

Patent metadata

Field	Value
Publication number	US-10369727-B2
Application number	US-201615156297-A
Country	US
Kind code	B2
Filing date	May 16, 2016
Priority date	Mar 31, 2008
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

An object of the invention is to provide a blow-molded foam which has homogeneous foamed cells in size, is light in weight, and is excellent in surface smoothness, and a process for producing the same. The invention is directed to a blow-molded foam 1 having a wall portion formed in such a manner that a thermoplastic resin containing a foaming agent mixed therewith is subjected to blow molding. Herein, the wall portion has a closed cell structure in which a plurality of foamed cells are contained. The wall portion has an expansion ratio of not less than 2.0 times. The wall portion has an outer face having a center-line average surface roughness Ra of less than 9.0 μm. The foamed cell has a cell diameter having a standard deviation of less than 40 μm in a thickness direction of the wall portion.

First claim

The invention claimed is:

1. A blow-molded foam configured for use for a climate control duct for a vehicle, said blow-molded foam comprising:
a wall portion formed in such a manner that a thermoplastic resin containing a foaming agent mixed therewith is subjected to blow molding,
wherein
the wall portion has a closed cell structure in which a plurality of foamed cells are contained,
the wall portion has an outer face configured to be provided on an inner side of the climate control duct and having a center-line average surface roughness Ra of less than 9.0 μm to reduce frictional resistance against flowing air and to improve ventilation efficiency,
the foamed cell has a cell diameter having a standard deviation of not more than 20 μm in a thickness direction of the wall portion, and
the blow-molded foam comprises a main body including an air inlet and an air outlet.

2. The blow-molded foam according to claim 1 , wherein
the thermoplastic resin is a polyolefin-based resin.

3. The blow-molded foam according to claim 2 , wherein
the polyolefin-based resin is a propylene homopolymer having a long-chain branched structure.

4. The blow-molded foam according to claim 3 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 300 μm.

5. The blow-molded foam according to claim 3 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 100 μm, and the standard deviation of the cell diameter of the foamed cell in the thickness direction of the wall portion is less than 30 μm.

6. The blow-molded foam according to claim 2 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 300 μm.

7. The blow-molded foam according to claim 2 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 100 μm, and the standard deviation of the cell diameter of the foamed cell in the thickness direction of the wall portion is less than 30 μm.

8. The blow-molded foam according to claim 1 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 300 μm.

9. The blow-molded foam according to claim 1 , wherein
an average cell diameter of the foamed cell in the thickness direction of the wall portion is less than 100 μm and the standard deviation of the cell diameter of the foamed cell in the thickness direction of the wall portion is less than 30 μm.

10. The blow-molded foam according to claim 1 , wherein the closed cell structure has a closed cell ratio of not less than 70%.

11. The blow-molded foam according to claim 1 , wherein the wall portion has an average thickness of not more than 3.5 mm.

12. The blow-molded foam according to claim 1 , wherein a parting line is formed between the air inlet and the air outlet.

13. The blow-molded foam according to claim 12 , wherein the parting line is formed by having a parison made of the thermoplastic resin between split mold blocks, and extends between the air inlet and the air outlet along a side face of the main body.

14. The blow-molded foam according to claim 12 , wherein the parting line is formed at a parison made of the thermoplastic resin, and extends between the air inlet and the air outlet along a side face of the main body.

15. The blow-molded foam according to claim 1 , wherein the main body has a hollow structure surrounded by the wall portion.

16. The blow-molded foam according to claim 15 , wherein the blow-molded foam defines a climate control duct configured to cause climate control air that flows into the air inlet, to flow, through the hollow structure, out from the air outlet.

Assignees

• Kyoraku Co Ltd
• Kyoraky Co Ltd

Inventors

• Onodera Masaaki
• Sumi Takehiko
• Tamada Teruo
• Igarashi Yu
• Ohno Yoshinori

Classifications

• B29L2022/00

  Hollow articles (tubular articles B29L2023/00; pneumatic tyres B29L2030/00) · CPC title

• B29L2031/3005

  Body finishings · CPC title

• B29C44/3469

  Cell or pore nucleation · CPC title

• B29C44/352 Primary

  Means for giving the foam different characteristics in different directions · CPC title

• B29K2023/10

  Polymers of propylene · CPC title