| 摘要 |
1,240,653. Coated sheet material. DURIE & MILLER (HOLDINGS) Ltd. 9 Oct., 1968 [10 Oct., 1967], No. 46314/67. Heading B2E. Rubber and/or plastics layer, sheet or film is produced by coating a substrate with a foam composition comprising the rubber and/ or plastics, gelling the coating to a form-stable state, drying or substantially drying the coating and then subjecting the entire coating to pressure to collapse the foam to form a substantially solid sheet. The rubber may be a natural or synthetic rubber and the foaming can be carried out either by mechanical means or chemical means or both. The substrate may be a plate or endless belt from which the finished sheet is to be removed, or may be a textile or other substrate which is to be coated with a sheet of rubber or plastics. The foam may be crushed by pressing through calender rollers which may be plain or patterned. After crushing the foam may be heated to a temperature sufficiently high to cure the rubber or plastics. In an Example, a latex comprising styrene-butadiene rubber, carboxylated styrenebutadiene rubber, natural rubber, potassium oleate, sulphur, accelerator, antioxidant, pigment, foam stabilizer and mineral filler is mechanically foamed, chilling agents blended into the foam, and the foam then sprayed onto a fabric substrate and passed beneath a bank of infra-red heaters which gelled the foam. The gelled foam is then passed into a heated oven for drying, and between calender rollers for crushing and finally through a second heated oven for final curing. The coated fabric can be taken off the calender rollers in an uncured state so that it can be cured in situ during the main fracture of end product. |
