Improvements relating to honeycomb type structures
Bailey, C. J., Ansell, J. J., Davey A. E. and Payne, K. G. (Rolls-Royce, Composite Materials, Ltd) UK Patent
A number of identical plastics units are mounted between skins of metal or plastics material to form rigid strong honeycomb structures. Nine diagrams illustrate the various configurations designed for this honeycomb unit. Shell structures are completed by providing capping pmces and end walls to produce continuous surfaces. Curved bodies can be produced using the same unit, without impairing shear strength.
Process for producing thermoplastic resins which are reinforced with glass fibres
Hermann, K. H., Roederer, F. and Leister, K. (Farbenfabriken Bayer Aktiengesellschaft) UK Patent Specifi-
hydrostatic extrusion press produces a composite, the core of carbon fibre reinforced resin being sheathed in metal. Z, L, T and I section beams may be produced, being applied as stringers, for example, to stabdize and strengthen a sheet structure. Improvements in or relating to process for the production of carbon filaments
(Sigri Elektrographitgesellschaft mit Beschrankter Haftung) UK Patent
T o produce carbon filaments, the precursor Is heated in air while maintained under tension. This pretreatment step takes about 24 hours. T o reduce this time, a dehydrogenation agent is used with a fibre capable of undergoing crosslinking. T h e temperature is advanced by up to 35°C per hour. Oxygen, chlorine and liquid sulphur may be used as the agents, the pre-treatment being carried out under a pressure higher than atmospheric pressure. A fibre having uniform strength is produced.
cation, 1,231,608 (1'2 May 197!) T o overcome the practical difficulties of mixing glass fibres in a thermoplastic resin matrix using a screw extruder, the molten resin is stirred to present a 'trumpet-shaped surface'. A ratio of 80% glass fibres can be evenly distributed in the resin, because of the even circulation caused by the vortex. However, the output of a screw extruder diminishes because of the increased melt viscosity of the fibre reinforced resin, and wear of the machinery is heavy.
oxidized in the fluidized bed, p r i o r to pyrolysis, by the c o m p r e s s e d air, which is also the fluidizing medium. T h e treatment lasts from ½ to 8 hours in a temperature range of 200oC to 350°C. Local hot spots, which occur in a normal air furnace, are eliminated, making the etching of a tow of fibres feasible.
Reinforced honeycomb construction and method of making same
(United Aircraft Corp) UK Patent Specification, 1,233,018 (26 May 1971) T o allow honeycomb to be machined and bear compressive loads, end-grain balsa wood is pressed into the cells of the honeycomb, thereby producing rigidity of the structure. A low viscosity epoxy resin is applied to pioduce a bond between honeycomb and balsa. T o produce a sandwich construction, opposite faces of the honeycomb have plastics impregnated glass fibre cloth bonded to them. A helicopter motor cap is given as an applied example.
Glass fibre-elastomer assembly
Marzocchi, A. (0wens-Coming Fiberglas Corp) UK Patent Specification,
1,232,279 (19 May 1971) In making a composite from a matrix of elastomeric material and glass fibre reinforcement, a polyfunctional organic compound is used to coat the glass fibres. T h e organic compound is a solvent or plasticizer for the elastomeric material. U n d e r heat and pressure the matrix immediately adjacent to the surfaces of the glass fibre are reduced to a state of tow viscosity therefore better penetration by the matrix is achieved.
Reinforced foam plastics artides
Hoppe, P. (Farbenfabriken Bayer Aktiengesellschaft) UK Patent Specifi-
cation, 1,233,910 (3 June ]97]) Reinforced foam plastics, preferably polyurethane, adheres to an outer surface layer by reinforcing mats. These mats of woven fabric are joined at one surface with a tangled fleece, the free ends of which extend far into the foam plastics. Anchored in this x~ay, the system can withstand high stresses. Automobile bodies, aircraft compartments and the hulls of boats are particular areas for application.
Forming mats of carbon filame~tts
Chapman, D. R. and Rex, N. R. (Courtaulds Ltd) UK Patent Specifica-
tion, 1,232,007 (19 May 1971) Carbon filaments in the form of staple fibres are both brittle and have little cohesion when dry. T o form a randomly oriented mat of the fibres, therefore, filaments are dispersed in an agitated trougqa of water, which also contains a wetting agent. Carried over an overfow, the fibres are deposited on a grid and retained as a compact mat, which can subsequently be impregnated with a resin.
Improvements in or relating Io extruded composite plastics filaments
Dow, J. and Jones, B. M. (Smith g: Nephew Research L t d ) UK Patent
Specification, 1,232,'282 (19 ]97])
A mixture of two crystalline polymers, polyetheylene and polypropylene, are used to produce a composite filament by extrusion and drawing. T h e extruded filament is quenched and subsequently drawn out under tension. Applications include use as a filter medium for separating suspended solids from liquid or a capillary medium for absorbing liquid. T h e product can be formed as a pad, a staple fibre o r a woven or non-woven fabric.
Improvements in or relating to composite nmterial articles
Molyneux. W. G. (National Research & Development Corp) UK Patent
Specification, 1,'23'2,055 (19 1971)
A tow of carbon fibres is impregnated with a resin, which is partially cured. ~lhe comoosite tow is threaded into a block of extrudable metal, particularly aluminium alloy. Extrusion from a
Improvements in or relating to producing carbon fibre reinforced composite materials
Process tor the production ot thermoplastic resins reinforced with glass fibres
Hermann, K. H. and Roederer, F. (Farbenfabriken Bayer Aktiengesellschaft) UK Patent Specification,
1,234,199 (3 ]une 1971) Two improvements are presented in the production of glass fibre reinforced thermoplastic resins, using a single screw extruder. T o prevent excessive wear, the cylinder and screw are coated with stellite or tungstenc a r b i d e / c o b a h alloys, for example. T h e screw and cylinder are conical at the inlet, being 1½ times the diameter of the outlet. This tapering exerts preliminary compression on the b u l k y glass fibres, which are more firmly gripped. Rates of throughput can be increased from 2 to 4 times.
Johnson, J. W. and Whitney, I. (RollsRoyce Ltd) UK Patent Specification,
1,232,461 (19 May 1971)
Patent Specification, 1,°34,208 ]une 1971)
In the production of carbon fibre, a polyacrylonitrile fibre is heat treated m a fluidized bed. T h e fibre is
Long, C. A. F. (Courtaulds Ltd) UK
Carbon fibres are laid in a mould, either randomly oriented or parallel
COMPOSITES September 1971 199