Process for manufacturing a differentially expanded resinous cellular sheet
AssigneeReed International Limited
InventorsRodney John Briston, Rodger George Canning, John Parker Tomlinson
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Abstract
A process for the manufacture of a differentially expanded sheet material comprises applying an organic solvent to the surface of an expandable thermoplastic sheet containing a blowing agent and allowing the treated sheet to at least partially dry before a composition containing a metallic powder and a kicker for the blowing agent is applied to selected areas of the treated surface. The sheet is then uniformly heated to a temperature at which the blowing agent in contact with the kicker decomposes but below that at which it decomposes in the absence of the kicker, so that the areas of the sheet in contact with the kicker expand to a greater extent than the uncontacted areas.
Claims11
A process for the manufacture of a differentially expanded resinous cellular sheet, comprising applying an organic solvent to the surface of an expandable sheet composed of a thermoplastic resinous composition having a blowing agent incorporated therein, said solvent having an affinity for said resinous composition;
- allowing the solvent-treated sheet to at least partially dry;
- applying a composition containing a metallic powder and a kicker for the blowing agent to portions of the solvent-treated surface, adhesion of the metallic powder composition to said sheet being enhanced by the solvent treatment;
- and then uniformly heating the treated sheet for a time and at a temperature at which the blowing agent decomposes in the presence of the kicker but below that at which it decomposes in the absence of the kicker so that those portions of the sheet which received an application of metallic powder and kicker containing composition expand to a greater extent than those portions which did not receive an application of metallic powder and kicker containing composition to produce said differentially expanded sheet.
Dependencies are inferred from the claim text.