| 摘要 |
1,048,268. Moulding plastic substances etc; laminates and laminating. MARLEY TILE CO. Ltd. Sept. 14, 1964 [Sept. 12, 1963], No. 37494/64. Divided out of 1,048,267. Headings B5A and B5N. A method of producing cold-cured polyurethane foam sheeting, in particular for flooring materials, as described in Specification 1,048,267, comprises feeding a polyurethane foam-forming composition between conveyers 1, 2 which move at substantially the same speed and allowing the composition to expand therebetween, the resultant foam having a density in the range from 4-12 lb./cu. ft. and a load-bearing capacity in the range of from 1À0-12À0 lb./sq. in. at 25% compression, 2À5-30À0 lb./sq. in. at 50% compression and 13À0 to 138À0 lb./sq. in. at 75% compression. The conveyers are preferably of stainless steel and the upper one is vertically adjustable, the moulding space 6 being defined laterally by plates having gas outlets 7, Fig. 2 (not shown). The foam-forming composition is fed from a horizontally reciprocable dispenser 10, having a fan-shaped nozzle 12, on to a backing material 8, made of, e.g. paper, P.V.C. or woven fabric, and is evenly spread on the backing layer by the action of roll 4. Paper or the like sheeting 9 is fed in contact with the upper conveyer 2 to prevent the foam sticking thereto and the paper may contain a release agent, e.g. silicone, so that if desired, it may be stripped from the final product. Final curing may be effected using a radiant heater 14 and the product is cut by a guillotine 15. Also the edges of the sheeting may be trimmed. In a second embodiment, Fig. 4 (not shown), particularly intended for the production of polyurethane foam sheeting without a backing, the lower conveyer 1 extends under dispenser 10 and both conveyers are coated with a release agent, e.g. a wax solvent, using sprays 19, 20. The constituents of the polyurethane foam-forming composition and of the backing layer are given in the above-mentioned Specification. |
