method and device for continuous production of a small thick self-supporting schaumes

摘要

1313103 Urea/formaldehyde foams BRITISH INDUSTRIAL PLASTICS Ltd 13 July 1970 [17 July 1969] 36069/69 Heading C3C A low density, self-sustaining foam is formed by foaming a mixture including an aqueous solution of a thermosetting material comprising a urea/formaldehyde resin and a foaming agent to produce a first foam, foaming a mixture including an aqueous solution of a hardener for the resin and a foaming agent to produce a second foam and mixing the first foam with the second foam. Apparatus disclosed has at least two foaming units each provided with foam inducing packing, a gas-feed inlet and a liquidfeed inlet into which the two mixtures are fed under gas pressure, the resultant foams being fed to and mixed in a foam-mixing unit. Both mixtures may be heated at the liquid feed inlet. The ratio by volume of resin and hardener is in the range 4 : 1 to 50 : 1. The resin may be a simple urea/formaldehyde or modified, examples being given. Typical foaming agents are also referred to.