| 摘要 |
<p>A heat-plastified, resinous, synthetic compsn. is extruded through a die in the form of a tube having generally radial symmetry about the axis of extrusion. In this condition, the tube is passed past a cording mechanism with counter-rotating elements for impinging cooling means on the tube. - The film is fixedly spaced from the cooling means, the cooling means are impinged on the film body and the tube formed into a tough film with a ribbed pattern thereon imparted by the cooling elements. The cooling mechanism elements may counter rotate at the same speed; the cooling means may be angled w.r.t. the film. The cooling means may comprise cooled gas, vapour mist, snow, liquid or a combination. - The film produced not only has enhanced strength but can also be multilayered to present a visible rib by use of layers of contrasting colours.</p> |
