cloth by an electroless process. The metallized cloth is impregnated with resin, which is then cured. Other metals and cloths may be used. The resulting product is a resin impregnated sheet of cloth sandwiched by metallized faces. This material has good electrically conducting surfaces and adhesion between the components. Utility in the manufacture of pressure vessels for cryogenic fluids is suggested.
Methods of producing composite materials: filament winding of composite materials to produce flat plates Forsyth, P. J. E. and George, R. W.
UK Patent Specification (12 August 1970)
Laminated articles: fire-resistant laminate Wilson, W. J. and Wood, J. F. UK
A fire-resistant laminate is comprised of sheets of facing material and a foam layer. The isocyanate-based foam is bonded to a thin layer of an intumescent coating, which is also applied to the facing sheet. This configuration both delays thermal decomposition and a rise in temperature of the laminate, due to the ablation properties of the intumescent coating.
Method of making fibre reinforced plaster articles National Research and Development Corporation UK Patent Specification,
1,204,541 (9 September 1970) E-glass fibres are used to reinforce plaster to produce reinforced piaster boards, mouldings and extrusions for constructional use. Chopped fibres are mixed with an aqueous slurry of gypsum plaster, the mixture then being moulded. Water is drawn off by suction to hydrate the plaster. 10% by weight of glass fibres give good modulus of rupture and impact strengths. Ten samples show the range of properties achieved.
1,205,058 (16 September 1970)
COMPOSITES December 1970
Production of wound hollow bodies from fibre-strand reinforced synthetic resin Baer, J. UK Patent Specification,
1,206,133 (23 September 1970)
Glass fibre layers are bonded to form a container using a polyester resin matrix. The resin is cured with an organic peroxide catalyst. To neutralize the acids so formed, a small amount of sodium bicarbonate is added to the resin mix. The outer surfaces of the container are fireproofed by adding chlorinated wax and antimony oxide to the resin mix used to bond the face of the composite.
A filament-winding machine for producing fibre reinforced hollow synthetic resin bodies is described. Electrical signals enable the winding operation parameters to be pre-set. Two counters are used to record the impulses, the second counter recommencing at zero on the completion of each winding cycle. The ratio of the rotation speed of the mandrel to the speed o f the carriage can be preselected.
Laminated structure: non-refiecting transparent laminate Armstrong, R. C. UK Patent Specifica-
Improvements in or relating to laminated materials: reinforced polymer f'dm Polymer Processing Research Institute Ltd, Tokyo, Japan UK Patent Specifi-
A drum of round or polygonal section is used to produce filament reinforced plates by filament winding. An outer layer of the matrix material is mounted, the reinforcing element is wound onto that layer, a further matrix layer is applied, and the final composite is produced by hot pressing or hot rolling the required number of layers. The polygonal drum offers the advantage of producing a number of flat plates in one winding operation. The filament is wound under light tension.
Patent Specification, August 1970)
Improvements in or relating to laminated materials: glass fibre reinforced container Rees, C. S. L. UK Patent Specification,
tion, 1,205,271 (16 September 1970) A transparent laminate suitable for application to welders' and astronauts' masks, infra-red rejecting window shades, and other uses overcomes the problem of reflected image. An infrared reflecting coating is applied to a roughened substrate, the matt surface diffusing the reflection and imaging. The outer transparent layers must have compatible refractive indices, the metallic coating having a higher refractive index. Process for the production of laminates: co-extrusion of a laminate Mitsubishi Petrochemical Co Ltd UK
Patent Specification, September 1970)
To overcome the 'neck-in' problem during the extrusion of thermoplastic resins, a laminate is p r o d u c e d from a single die, one film having a high neck-in forming property, the other resin having a low neck-in forming property. A more uniform film thickness can be achieved over wider areas and the winding of the laminate is improved. Waste at the edge of the film is minimal. The two components of the film can be combined before extrusion from the die slits or immediately below the outlet orifices.
Carbon fibre reinforced plastics Hall, R. W. UK Patent Specification,
A fibrillated plastics material is spread evenly and laminated with a polymer film. Three methods of spreading the fibres are described, one being to charge the fibres electrostatically. The product is both soft and smooth and may be coated with either thin kraft paper, saving wood pulp, or metal foil, giving a product resistant to low temperatures and corrosion. Adhesion between fibrillated material and film is best when they are based upon the same type o f polymer. Improvements in or relating to the continuous production of a fibrereinforced plastics material Lockhart, W. N. and Morris, D. R. UK
Patent Specification, September 1970)
A continuous production method for glass fibre reinforced plastics extrusions is described. The fibres are initially impregnated with a thermosetting resin, then a liquid plastic is injected to coat the impregnated fibres. Extrusion through a heated die cures the product. A resin-rich surface may be produced. Configuration of the die is shown in a diagram. Carbon filaments: production of carbon fibres in a fluidized bed Higgins, F. J. UK Patent Specificatz'on,
1,205,852 (23 September 1970)
1,207,152 (30 September 1970)
Carbon fibre mat is modified by coating the fibres with an ionisable resin by electro-deposition. This i m proves the wetting characteristics of the fibres and thereby improves their adhesion to a plastics material in the final product. Coating resin and matrix resin are interdependent and careful selection is required. The modified fibres may be used with glass fibres either as mixtures or woven into mats.
The carbonization of polyacrylonitrile fibres is achieved in a fluidized bed of glass beads. The filaments are heated in the bed to a temperature in the range 220°C to 280°C. An oxidizing atmosphere is present, but the fluidized bed material must be chemically inert to the fibres. The fibres must also be kept in tension, to control their length. The process can be operated continuously.