EP0385349A2
Expired / Lapsed
EP
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Process for preparing extruded foam bodies
Assignee: UC Industries Inc
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Filing: 1990-02-26
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Granted: —
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Expires: 2010-02-26
Abstract
Abstract A process for preparing an extruded thermoplastic resin elongate foam body comprising an alkenyl-substituted aromatic resin is described. The process comprises the steps of (A) heat plastifying the thermoplastic resin; (B) adding at least one fluid blowing agent comprising at least one of 1-chloro-1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and 2-chloro-1,1,1,2-tetrafluoroethane; (C) uniformly mixing the blowing agent in the resin under a pressure sufficient to prevent blowing of the resin thereby forming a blowable resin mixture; (D) extruding the mixture into a region of reduced pressure which is less than atmospheric pressure wherein the blowable resin mixture expands into a foam body; and (E) cooling the foam body.
Inventors
- 👤 Joseph A. Brackman
- 👤 Raymond M. Breindel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 20:40
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/001; B29C48/0012; B29C44/00; B29C44/34; B29C44/3403; B29C44/3407; B29C48/03; B29C48/07; B29C48/25; B29C48/88; B29C48/90; B29C48/919; C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/122; C08J9/14; C08J9/143; C08J9/144; C08K; C08K3/00; C08K3/18; C08K3/24; C08K3/26; C08K3/34; C08L; C08L25/00; C08L25/02; C08L25/04; C08L25/06; B29C48/904; B29C48/906; C08J2325/00; C08J2325/02; C08J2325/04; C08J2325/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
A process for preparing an extruded thermoplastic resin elongate foam body comprising an alkenyl-substituted aromatic resin characterized as having a density of between about 0.9 and about 3.5 pounds per cubic foot which comprises the steps of (A) heat plastifying said thermoplastic resin; (B) adding at least one fluid blowing agent comprising at least one of 1-chloro-1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and 2-chloro-1,1,1,2-tetrafluoroethane; (C) uniformly mixing the blowing agent in the resin under a pressure sufficient to prevent blowing of the resin thereby forming a blowable resin mixture; (D) extruding the mixture into a region having a pressure from about 2 to about 27 inches of mercury absolute wherein the blowable resin mixture expands into a foam body; and (E) cooling the foam body.
Claim 2
Dependent Claim
121 words
A process for preparing an extruded thermoplastic resin elongate foam body comprising an alkenyl-substituted aromatic resin characterized as having a density of between about 0.9 and about 3.5 pounds per cubic foot which comprises the steps of (A) heat plastifying said thermoplastic resin; (B) adding at least one fluid blowing agent comprising at least one of 1-chloro-1,1-difluoroethane, 1,1,1,2-tetrafluoroethane and 2-chloro-1,1,1,2-tetrafluoroethane; (C) uniformly mixing the blowing agent in the resin under a pressure sufficient to prevent blowing of the resin thereby forming a blowable resin mixture; (D) extruding the mixture into a region having a pressure from about 2 to about 27 inches of mercury absolute wherein the blowable resin mixture expands into a foam body; and (E) cooling the foam body.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the blowing agent further comprises dichlorodifluoroethane, chlorodifluoroethane, carbon dioxide, or mixtures thereof.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein the mixture is free of ethyl chloride, methyl chloride, methyl alcohol, ethyl alcohol and isopropyl alcohol.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the alkenyl-substituted aromatic thermoplastic resin is a polystyrene.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein the foam body has an average cell size of about 0.2 to about 0.5 mm.
Claim 7
Dependent Claim
58 words
The process of claim 1 wherein such region of step (D) is formed by an elongated chamber with such mixture passing through a die at one end of such chamber and such foam body passing through a pool of water at the opposite end of such chamber and then passing such foam body from such chamber to atmosphere.
Claim 8
Dependent Claim
107 words
The process of claim 1 including the step of passing such mixture through a fan shape die in such region of step (D) to form a continuous foam body board wherein such die is a fan shape die having an arcuate slot orifice, and controlling the expansion of the mixture by arcuate rolls positioned above and below the plane of the arcuate slot orifice; wherein such arcuate rolls comprise a series of wafers driven for rotation at a controlled speed; and wherein the rolls above the plane of the orifice are floatingly supported to exert a controlled floating pressure on the mixture as it exits the die.
Claim 9
Dependent Claim
13 words
The process of claim 1 wherein the blowing agent further comprises carbon dioxide.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein the blowable resin mixture further comprises a nucleating agent selected from talc, calcium silicate, calcium carbonate and indigo.
Claim 11
Dependent Claim
21 words
The process of claim 1 wherein the blowing agent futher comprises carbon dioxide and the blowable resin mixture further comprises talc.
References Cited (Backward Citations)
No citation records indexed.
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