Verfahren zur Erzeugung von geschaeumtem Polyaethylen und daraus hergestellten Gegenstaenden

摘要

Expandable polyethylene compositions contain as the blowing agent an alkane boiling at 30-70 DEG C. and azobisisobutyronitrile as a foam assist. There may also be present an acid such as citric acid together with a carbonate such as sodium bicarbonate, inert fillers such as titanium dioxide, clay, magnesium sulphate, pigments, and diatomaceous earth, together with subliming materials such as insecticides, bactericides, anticorrosives and aromatic compounds. Articles may be made by continuous extrusion at a temperature above the softening point of the composition or by moulding. Extruded sheet may be moulded into articles by heat and pressure or by a vacuum, or used in the manufacture of artificial leather by bonding to a base cloth or resin-treated paper with simultaneous embossing. Corrugated cardboardlike structures may be obtained by corrugating the foamed sheet which is then bonded on either side to two flat sheets (see Figs. 1-3, not shown). Sheets with reinforced edges may be obtained by bending back the edges and then heat welding as in Fig. 6 (not shown). Holes may then be punched in the reinforced edges (Fig. 5, not shown).