GB1348896A - Manufacturing porous bodies of resin-bonded fibrous material - Google Patents

Abstract

1348896 Moulding resin bonded fibrous materials A FRANCESCHINA and R BARTULI 19 April 1971 [10 Feb 1970] 21421/71 Heading B5A In a process for the production of porous, resin bonded, fibrous articles, crimped fibres 1 are pulled, by means 12, through a guide 2 and into a vat 7 of a thermosetting resin 8 of the type which is adapted to be subjected to two polymerization stages-an intermediate stage in which it becomes hard and insoluble but capable of melting, when subjected to further heating, to give a final polymerization stage in which it is infusible-the soaked bundle 3 of fibres is passed through rollers 9, 6 to remove excess resin, through a drying and pre-heating chamber 10, and into a draw member 11, where the bundle is stretched, shaped and heated to a temperature at which the intermediate polymerization state is achieved; the shaped rod 103 so produced is pulled through the belts 112, 212 of the means 12 to a cutting device 13, the cut lengths 203 are then heated in a mould (14, Figs. 2-5, not shown) to the final polymerization stage. The final heating, which melts the intermediate polymer, allows the stretched fibres to relax and assume, at least partially, their original crimped configuration. In relaxing, the fibres expand to some extent and create a porous structure. The resins used may be phenolic, or an amino resin. Alternatively, using a modified apparatus a thermoplastic resin may be employed. The fibres can be natural, synthetic, or a mixture of both.