Cold molding of flexible articles
AssigneeHer Majesty the Queen in right of Canada, as represented by the Minister of National Defence
InventorsJacques Ratte, Pierre Carignan
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Abstract
A novel process for the preparation of flexible molded articles, such as head-end insulators for rocket casings, which are exposed to extremely high temperatures. The articles are cold-molded from shreds, discs or strips consisting of asbestos fibers and floats impregnated with a substantially uncured elastomeric binder comprising a carboxyl-terminated polybutadiene polymer.
Claims15
A method of manufacturing a flexible, uncured molded article, said method comprising the steps of:
- (a) forming a sheet material comprising about 20 to 50% by weight of a substantially uncured elastomeric polymeric binder having dispersed therethrough a siliceous filler reinforcing material in an amount of from about 80% to about 50% by weight, at least about half of said reinforcing material being in fibrous form and the balance in the form of floats;
- (b) process said sheet material into strips, discs or shreds;
- (c) maintaining said strips, discs or shreds at sufficiently low temperature to at least inhibit curing thereof;
- and
- (d) cold-molding said strips, discs or shreds in a substantially uncured condition to form said uncured molded article.
A method of manufacturing an uncured, flexible head-end insulator for use in the propellant chamber of a rocket motor, said method comprising the steps of:
- (a) forming a sheet material comprising about 20 to 50% by weight of a substantially uncured carboxyl-terminated polybutadiene binder having dispersed therethrough an asbestos reinforcing material in an amount of from about 80% to about 50% by weight, at least about half of said reinforcing material being in fibrous form and the balance in the form of floats;
- (b) processing said sheet material into strips, discs or shreds;
- (c) maintaining said strips, discs or shreds at sufficiently low temperature to at least inhibit curing thereof;
- and
- (d) cold-molding said strips, discs or shreds in a substantially uncured condition to form said uncured head-end insulator.
A method of manufacturing a flexible, uncured, rocket motor propellant head-end insulator adherable to metal surfaces, said method comprising the successive steps of:
- (1) mixing together from about 25% to about 35% by weight of a substantially uncured carboxyl-terminated polybutadiene binder with from about 75% to about 65% by weight of an asbestos filler reinforcing material, the total of said binder and filler amounting to 100%,
- at least about half of said reinforcing material being in fibrous form, the balance thereof in the form of floats;
- (2) continuing said mixing and thoroughly dispersing said reinforcing material through said binder to form a mixture;
- (3) forming the mixture of step (2) into a sheet material;
- (4) shredding said sheet material of step (3) into strips, discs or shreds;
- and
- (5) cold-molding said strips, discs or shreds in a substantially uncured condition and under pressure to form said head-end insulator,
- wherein each of steps (1)-(5), inclusive, is conducted at a temperature such that curing of said binder is prevented or inhibited,
- thereby producing a flexible, cold-molded heat-end insulator in the uncured state.
A method of manufacturing a flexible, uncured, rocket motor propellant head-end insulator comprising the successive steps of:
- (1) mixing together from about 20% to about 50% by weight of a substantially uncured carboxyl-terminated polybutadiene binder with from about 80% to about 50% by weight of a siliceous filler reinforcing material,
- at least about half of said reinforcing material being in fibrous form, the balance thereof in the form of floats;
- (2) continuing said mixing and thoroughly dispersing said reinforcing material through said binder to form a mixture;
- (3) forming the mixture of step (2) into a sheet material;
- (4) shredding said sheet material of step (3) into strips, discs or shreds;
- and
- (5) cold-molding said strips, discs or shreds in a substantially uncured condition and under pressure to form said head-end insulator,
- wherein each of steps (1)-(5), inclusive, is conducted at a temperature such that curing of said binder is prevented or inhibited,
- thereby producing a flexible, cold-molded head-end insulator in the uncured state, which head-end insulator has the ability to adhere to metal surfaces.
Dependencies are inferred from the claim text.