Production of foams

A method of continuous upward production of foamed material, in which foam forming liquid reactant materials are mixed and fed at a controlled rate to a sealed feed zone leading into an upwardly diverging expansion enclosure wherein foaming takes place and thence into an upwardly extending take-off path for expanded foam, the feed zone being continuous with the expansion enclosure, in which the expansion enclosure is defined above by already expanded foam in the take-off path and at the sides by travelling sheet material drawn upward from above the expansion enclosure so that the surface of the body of expanding foam and the travelling sheet material move together;

• it being assured that expansion is not completed before the end of the diverging portion of the expansion enclosure is reached;
• and the travelling sheet material being constituted by a tubular web fed in collapsed form and expanded by the foaming materials.

A machine for continuous production of foamed material, comprising feed means for feeding foam forming materials from below at a controlled rate, take off means for drawing the foamed material formed away from above at a corresponding rate, means forming a diverging expansion enclosure bounded by moving sheet material constrained to follow a diverging path and drawn away from above so as to travel with the foaming material at a rate corresponding to its rate of travel, in which diverging expansion enclosure foaming takes place, said enclosure being defined above by foam already expanded, at the sides by said sheet material, and below by a feed zone sealed to contain the foam forming materials, the enclosure leading into an upwardly directed take off path for the foam, wherein the expansion enclosure is formed by flexible sheet material in tubular form which is fed flat with foam forming materials passing to the interior of the tube and then drawn away at a rate matched to the rate of feed, guided externally to assume a predetermined open cross section as the foam forming materials expand within it, and constituting both said feed zone and said expansion enclosure.