Improvements in and relating to the manufacture of flexible bands, threads and foilsof polystyrol or like artificial substances

摘要

Flexible bands and threads of polymerization products of aryl olefines, such as polystyrol, particularly useful as insulating materials, are produced by pressing the material through a nozzle at high temperature, and drawing the bands and threads at a speed which is greater than the outlet speed of the nozzle. Preferably, the drawing speed is sufficient to reduce the cross-section of the band or thread to at least half that of the nozzle. In the case of bands, these may be subjected, during or immediately after the drawing process, to a transverse stretching, e.g. so that the thickness of the band is reduced to about one-ninth. A suitable apparatus comprises a nozzle 1 of rectangular cross-section, two endless bands 2, diverging away from the nozzle, and provided with pins 4 to engage the band of polystyrol, and a winding device 5. Specification 407,663 is referred to.