Method of impregnating porous ceramics

heat treatment zone with an increasing temperature gradient. T h e overall direction of travel of the filamentary material is i n the direction of increasing temperature and the direction of travel within each compartment being substantially at ril~ht angles to the direction of increasing temperature. This enables the continuous production of carbon .filament to take place at an increased rate. Improvements in and relating to electrodepoaRed composite coatings

Kedward, E. C. and Leeson, J. (Bristol Aerojet Ltd) UK Patent Specification,

1,236,954 (23 June 1971)

A process is described in which a surtace is coated with a composite coating of a metal or alloy matrix in which particles are dispersed. T h e metal or alloy is electrodeposited on the surface from an electroplating solution containing the particles and in which a stream of j~as bubbles up to 1 mm in diameter-trows across the surface. This gas flow improves the i:oating reducinl~ the tendency for particle aggregation. Composite roofing material with b m t h ing layer

Reid, D. H. (D. Anderson 8c Son Ltd)

UK Patent Specification, (30 June 1971)

1,237,127

A composite roofing material consisting of layers of a water resistant and heat insulation material in which the water resistant layer is provided With a number of perforations which result in projections on the surface remote from the heat insulation material. This layer acts as a breathing'layer so that any water vapour present under or in the insulauo" n layer may pass upwards through the water resistant layer but the passage of rain or snow is resisted. Improvements relating to impregnation apparatus

Thorpe, B. T. (Muirhead Ltd) UK

Patent Specification, June 1971)

1,237,565 (30

An apparatus for impregnating articles is described in which articles are fitted to holders which house rotatable mandrels. A drive extends along the path of movement of the holders co-operating with them to spin the m a n d r e l s about their axis while moving along. An impregnation applicator is described together with an oven system which ensures at least partial cure after impregnation fluid addition is complete. Reinforced polymer compositions

Gobbert, D. J., Hedrick,'R. M. and Tierney, P. A. (Monsanto Co) UK

Patent Specification, 1,237,844 (30 June 1971) A reinforced polymer composite consisting of a polymer matrix of at least 50% polyamide of intrinsic viscosity 1.3, containing 2-55% by volume of an anhydrous particulate inorganic filler having a Moll's hardness of at least 4 and specified particle size, this filler having been

treated with an or~nosilicone coupling agent of specified composition. These composites show high multiaxial impact strength while still retaining other desirable properties. lmprovememts in and relating to a method and apparatus for the mamnfmclure of resin impregnated board units

Helgesson, J. A. G. (Ingenjorsfirma B-Projekt AB) UK Patent ~pecifica-

tion, 1,237,902 (30 June 1971) A method is described for the manufacture of board units of finely divided vegetable material impregnated with resin, faced on one side with a layer of flexible material in the form of a web. T h e web, resin and finely divided material are fed to a hot press after which the cured board is cut into units. This system is superior to earlier methods in that the number of processing operations is both reduced and simplified, upgrading efficiency and lowering unit cost. Composite metal articles

Featherstone," R. W. and Davies, J. P. (Dunlop Holdings Ltd) UK Patent

Specification, 1,238,183 (7 July 1971) method is described for produc!ng a porous composite article consisting of largely metal. A foam cellular structure is coated with metal or metal alloy either by electro or chemical deposition. T h e polymer can be chemically removed if required. These foam metal composites are useful in applications such as abradable seals and bearings; in such applications the cells may be left open or sealed with eve, for bearing applications lubricants such as graphite are used. Treatment of carbon fibres

Morgan, P. E. (Courtaulds Ltd) UK

Patent Specification, July 197 0

1,238,308 (7

T h e surface of carbon filaments may be modified to produce an improved bond with resin. Treatment of filaments both graphitic and nongraphitic with liquid oxidizing agents is described. Oxidizing agents employed include nitric acid and a mixture of nitric and sulphuric acid, perchloric acid, hydrogen peroxide and other materials. T h e resultant carbon filaments resulted in improved shear properties in composites over earlier materials. A process for the produetiom of a multilayer composite cylindrical member

(Siemans Akt-Ges) UK Patent Specification, 1,239,005 (14 July 1971) A muhi-layer cylindrical member is produced by coating a niobium tube with a lower melting point alloy, followed by spraying on an insulation such as alumina. Finally the insulation is coated with more alloy and another niobium tube is fitted over this by heat shrinking. This composite anode exhibits excellent thermal union at the interfaces due to good wetting by the alloy.

Applrmms

for

tin

produalion

of

s 3 w a m ~ p ~ t i c pJpm or of tebubr bodies of s3qmeteflc resin impregnated rovines

(Mancar-Trust) UK Patent Specification, 1,239,294 (14 July 1971) An apparatus is described for p rroducing plastics pipes or tubes from rovings impregnated with synthetic resin. It consists of a constant s.peed driving shaft o p e r a t i n g a carnage adapted to carry roving bobbins along a path parallel te the longitudinal axis of a winding core. At least one swivelling impregnating trough with built-in drive and roving guide is used. T h e resultant wound body consisting of crossing layers of rovings withstands high bursting pressure. Reinforcement of thermopht~ic sheet

Cox, J. R. UK Patent Specification,

1,239,579 (21 July 1971) Single reinforcing wires are heated' by an electric current sufficient to coat the wire with a thermoplastic. T h e heated wires are pressed between layers of thermoplastic sheet and allowed to cool. T h e wires may be tensioned to avoid distortion during heating. T h e principal advantage of the method is that the reinforcing wire is attached to the sheet by a continuous fused permanent bond along its entire length. Laminated structure of metal and plastics

(Badische Anilin g: Soda Fabrik AktGes) UK Patent Specification, 1,239,999 (21 July 1971) A laminate of corrosion resistant metal foil such as stainless steel and a terpolymer of ethylene-acrylic acid and t-butyl acrylate. The terpolymer is applied in film form in the temperature range 80-250°C. The advantage of the laminates are their superior shear strength, creep rupture strength and temperature resistance to earlier materials. Applications cited include building facings and components for automotives. Method of impregnating porous cermies

Nell, D. J. and Lewis, T. W. (Dresser Industries Inc) UK Patent Specifica-

tion, 1,240,274 (21 July 1971) T h e resistance of refractory ceramics to chemical attack is increased by reducing .P°r°sity" A method of impregnating l~.rous ceramic articles with non-colloidal ceramic particles is described. Chromic oxide was deposited in the pores of a zircon retractory, a material which is normally difficult to impregnate. Glass maple fibre body

W. H. W. UK Patent Specification, 1240,330 (21 July. 1971) Schuller,

A glass staple fibre body comprising a non-woven web of randomly arranged glass staple fibre is held together by a bonding agent; an open lattice of rovings overlying and attached to a t least one surface of the web and further glass staple fibre slivers overlying each open lattice of rovings, contact and bond with the underlying non-woven web. Increased tensile

COMPOSITES December 1971 263