Method of producing a thermoplastics material
First Claim
1. A method of producing a substantially void-free and substantially stiff laminated structural material which material includes thermoplastics matrix material and a fibrous reinforcement material in the form of a woven fabric, a non-woven fabric, a felt or a paper, said method consisting essentially of the successive steps of:
- (a) impregnating said fibrous material throughout with a first thermoplastics material which is soluble in a solvent and is applied in a solvent solution, the solvent of said solution being allowed to evaporate after impregnation, the amount of the first thermoplastics material with which the said fibrous material is impregnated being at least sufficient for thorough impregnation of the fibers, but insufficient for the matrix of the desired structural material;
(b) stacking at least two layers of thus impregnated fibrous material, in alternate sequence with interleaving layers of a second thermoplastic material in sheet form, the amount of the second thermoplastics material included in the stack being such that the total amount of thermoplastics matrix material present in the stack is sufficient to enable the desired substantially stiff laminated structural material to be produced;
(c) subjecting the thus formed stack to heat and pressure in a preheated mould or press for sufficient time, in excess of 10 minutes, to cause the first and second thermoplastics material to soften and flow and to cause said thermoplastics materials to bond together and to bond to the fibrous material in a substantially void-free manner and to cause the stack to conform to a desired intermediate stock form or final product form, whereby a substantially stiff laminated structural material is produced having a flexural strength of at least 250 MPA; and
thereafter(d) allowing the mould or press to cool sufficiently to avoid distortion of the laminated structural material thus produced before removal of said laminated structural material from the mould or press.
2 Assignments
0 Petitions
Accused Products
Abstract
A method is described of producing a laminated structural material which includes the steps of stacking alternately layers of thermoplastics sheet material and one or more layers of material to be laminated, the material having been impregnated with a second thermoplastics material prior to stacking, placing the stack in a pre-heated mould or press and subjecting the stack to heat and pressure for a time sufficient to cause the thermoplastics material to flow and bond together the layers of structural material to be laminated and allowing the mould or press to cool sufficiently to avoid distortion of the moulded part before removal from the mould or press.
14 Citations
17 Claims
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1. A method of producing a substantially void-free and substantially stiff laminated structural material which material includes thermoplastics matrix material and a fibrous reinforcement material in the form of a woven fabric, a non-woven fabric, a felt or a paper, said method consisting essentially of the successive steps of:
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(a) impregnating said fibrous material throughout with a first thermoplastics material which is soluble in a solvent and is applied in a solvent solution, the solvent of said solution being allowed to evaporate after impregnation, the amount of the first thermoplastics material with which the said fibrous material is impregnated being at least sufficient for thorough impregnation of the fibers, but insufficient for the matrix of the desired structural material; (b) stacking at least two layers of thus impregnated fibrous material, in alternate sequence with interleaving layers of a second thermoplastic material in sheet form, the amount of the second thermoplastics material included in the stack being such that the total amount of thermoplastics matrix material present in the stack is sufficient to enable the desired substantially stiff laminated structural material to be produced; (c) subjecting the thus formed stack to heat and pressure in a preheated mould or press for sufficient time, in excess of 10 minutes, to cause the first and second thermoplastics material to soften and flow and to cause said thermoplastics materials to bond together and to bond to the fibrous material in a substantially void-free manner and to cause the stack to conform to a desired intermediate stock form or final product form, whereby a substantially stiff laminated structural material is produced having a flexural strength of at least 250 MPA; and
thereafter(d) allowing the mould or press to cool sufficiently to avoid distortion of the laminated structural material thus produced before removal of said laminated structural material from the mould or press. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification