| 摘要 |
1,141,894. Foamed polystyrene laminate. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 20 Feb., 1967, No. 7964/67. Heading B5N. A method of producing a laminated foamed polystyrene sheet comprises extruding a foamed polystyrene sheet, applying a liner sheet to the foamed sheet in a continuous operation with the extrusion of the foamed sheet firmly pressing the liner sheet and foamed sheet together to the extent that the foamed sheet is compressed by more than 75% whilst the foamed sheet material is in flexible condition, and heating the surface of the foamed sheet to the extent that when the liner sheet and foamed sheet are being pressed together the surface of the foamed sheet facing the liner sheet is at a temperature above the softening point of the foamed sheet material. In the method described foamed polystyrene is extruded in the form of a tube 2 from an extruder 1 and, after being stretched by inflating it with air from a conduit in the extruder, passes between heated compression rollers 5, 6 to which liner sheets 3, 4 of kraft paper are fed via heated rollers 7, 8 respectively. The rollers 5, 6 cause the two parts of the now flattened tube to be adhered together, cause the liner sheets to adhere to the flattened tube, cause the foamed material to be compressed more than 75%, and cause further foaming of the foamed material after it has passed between the rollers. The polystyrene may include n-butane and isobutane, or isopentane as foaming agent. |
