Imperial Chemical Industries Limited

Paul Snowden

Margaret L Steel

Fibres are produced by centrifugally spinning a formaldehyde resin, e.g. a UF resin, plus catalyst and contacting the spun fibres with a stream of hot dry air to dry the fibres. Cold, humid air is fed to the spinning cup to inhibit premature drying of the resin. The rotation of the cup causes the cold humid air to be thrown out of the cup with the fibres entrained therein. This entrainment serves to retard drying of the fibres while they attenuate.

Production of fibres

Process and apparatus for centrifugally spinning a fibre-forming material, e.g. a urea-formaldehyde resin, in which the fibre-forming material is supplied in liquid form to the interior of a spinning cup wherein it is divided into separate streams which are led to the outlets of passages through the wall of the spinning cup.

Spinning process and apparatus

Formaldehyde resin fibres, in particular urea formaldehyde resin fibres, are produced by introducing a liquid formaldehyde resin and a catalyst into a spinning cup in the presence of cold humid air which inhibits drying and reaction, centrifugally spinning fibres from the cup into the path of hot air currents, at between 50.degree. C. and 100.degree. C., which dry the fibres without curing them, and curing and chemically stabilizing the dry fibres by heating at above 100.degree. C. until they are insoluble in cold water.

A catalyst containing metallic copper, especially a low temperature shift catalyst containing also zinc oxide, is made from a corresponding catalyst precursor by reduction in two stages. In the first stage a steam and/or CO.sub.2 -diluted reducing gas is used and in the second a more strongly reducing gas mixture such as ammonia synthesis gas or even 100% hydrogen. The resulting catalyst is substantially more active than one reduced according to previous one-stage steam-reduction practice and similar to catalyst made by the less convenient dry-reduction using nitrogen or natural gas as diluent.

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Redcar, United Kingdom

Paul Snowden