GB600628A - Improvements in or relating to the manufacture of a composite fibrous sheet material - Google Patents

Abstract

A fibrous plastic composition is made by treating a minor proportion of an aqueous dispersion of an organic fibrous pulp material and a major proportion of an organic fibrous particulate material with a solution containing protein, depositing the protein on or in the fibres then treating the fibres while still wet with a solution, dispersion or emulsion of a partially condensed thermosetting synthetic resin, depositing the resin on the fibres and forming the slurry of treated fibres by a paper-making technique into sheet material and heating the latter with or without pressure to harden the protein and to convert the resin into the infusible state. The pulp and the particulate material can be treated separately with protein and coagulant and then mixed prior to treatment with the resin. The fibrous pulp material may be made from paper or wood. The fibrous particulate material may be sawdust or straw. The specified proteins are blood, soya bean protein, casein. Ammonium alum is the stated protein coagulant and precipitant for the resin. The protein may be associated with a hardening and insolubilising agent such as a mixture of ammonium hydroxide and paraformaldehyde. The specified resins are phenol-, urea-, cresol-, resorcinol-, thiourea-, melamine-formaldehyde. Fillers, pigments or dyes may be incorporated with the fibrous material.