EP0242191A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of producing foamed, molded article
Assignee: JSP Corp
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Filing: 1987-04-14
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Granted: —
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Expires: 2007-04-14
Abstract
Abstract Method of producing a molded article of a foamed thermoplastic resin including the steps of: (a) accumulating in an accumulator a molten mass of an expandable thermoplastic resin while preventing it from foaming; (b) ejecting a predetermined quantity of the accumulated thermoplastic resin all at once from the accumulator into the atmosphere so that the ejected thermoplastic resin commences foaming; (c) placing the ejected thermoplastic resin in a mold cavity before the expansion thereof has been completed; and (d) completing the expansion and molding of the ejected thermoplastic resin in the mold to obtain a foamed molded article.
Inventors
- 👤 Hiroyiki Akiyama
- 👤 Yoshimi Sudo
- 👤 Masahiko Kishika
- 👤 Mitsuru Nishika
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 18:38
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/38; B29C44/42; B29C44/421; B29B; B29B11/00; B29B11/06; B29C44/02; B29C44/10; B29C48/00; B29C48/25; B29C48/36; B29C48/375; B29C48/388; B29C2791/00; B29C2791/004; B29C2791/006; B29C48/03; B29K; B29K2033/00; B29K2105/00; B29K2105/25; B29K2105/253
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A method of producing a foamed molded article, comprising the steps of: (a) accumulating in an accumulator a molten mass of an expandable thermoplastic resin while maintaining said molten mass at a temperature and a pressure so that said molten mass is prevented from foaming; (b) ejecting a predetermined quantity of the accumulated thermoplastic resin all at once from said accumulator into an atmosphere maintained at a pressure lower than that within said accumulator so that the ejected thermoplastic resin commences foaming; (c) placing the ejected thermoplastic resin in a mold cavity before the expansion thereof has been completed; and (d) completing the expansion and molding of the ejected thermoplastic resin in the mold to obtain a foamed molded article.
Claim 2
Independent Claim
120 words
A method of producing a foamed molded article, comprising the steps of: (a) accumulating in an accumulator a molten mass of an expandable thermoplastic resin while maintaining said molten mass at a temperature and a pressure so that said molten mass is prevented from foaming; (b) ejecting a predetermined quantity of the accumulated thermoplastic resin all at once from said accumulator into an atmosphere maintained at a pressure lower than that within said accumulator so that the ejected thermoplastic resin commences foaming; (c) placing the ejected thermoplastic resin in a mold cavity before the expansion thereof has been completed; and (d) completing the expansion and molding of the ejected thermoplastic resin in the mold to obtain a foamed molded article.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1, wherein said thermoplastic resin is a polyolefin resin.
Claim 4
Dependent Claim
20 words
A method as claimed in claim 2, wherein said polyolefin resin is a polypropylene resin or a high density polyethylene.
Claim 5
Dependent Claim
30 words
A method as claimed in claim 1, wherein the ejected thermoplastic resin to be placed in the mold cavity in step (c) is in the form of a shaped body.
Claim 6
Dependent Claim
32 words
A method as claimed in claim 4, wherein, before step (c), said shaped body is cooled to form a skin layer over its surface and then heated to soften the skin layer.
Claim 7
Dependent Claim
29 words
A method as claimed in claim 4, wherein step (d) is effected using a pair of mold sections between which said mold cavity is defined when they are closed.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 4, wherein step (d) is performed while maintaining said mold cavity in a reduced pressure.
Claim 9
Dependent Claim
24 words
A method as claimed in claim 1, wherein the ejected thermoplastic resin to be placed in the mold cavity in step (c) is shapeless.
Claim 10
Dependent Claim
29 words
A method as claimed in claim 8, wherein step (d) is effected using a pair of mold sections between which said mold cavity is defined when they are closed.
Claim 11
Dependent Claim
78 words
A method as claimed in claim 8, wherein step (d) is effected using a pair of male and female mold sections moveable relatively to each other so that said mold cavity defined therebetween is changeable in length along which said mold sections are moved, and wherein step (d) includes compressing the shapeless ejected thermoplastic resin between said mold sections before the completion of the expansion, the resulting compressed resin being allowed to expand to obtain said molded article.
Claim 12
Dependent Claim
48 words
A method as claimed in claim 1, wherein said molten mass of the expandable thermoplastic resin is obtained by mixing the thermoplastic resin with a blowing agent at a temperature and a pressure so as to cause the resin to melt and to prevent the resin from foaming.
References Cited (Backward Citations)
No citation records indexed.
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