| 摘要 |
Continuous filamentary articles are made from latexes of synthetic organic, film-forming, normally crystalline high polymers capable of being obtained in a super-cooled amorphous state and of being oriented, said latexes being coagulable by aqueous solutions of electrolytes, by forming a continuous, coherent, self-supporting strip of coagulated latex by continuously wetting a travelling solid surface such as the peripheral surface of a rotating roll, or the upper surface of a travelling endless belt, with an aqueous solution of an electrolyte coagulant and then depositing thereon a thin narrow stream of latex, continuously stripping the strip of latex from the travelling solid surface, washing the strip free from coagulant, drying the strip under such conditions that its porous structure is not altered, forwarding the strip without applied tension through a radiantly heated zone maintained at a temperature sufficient to sinter and curl the strip and for a time sufficient to form a continuous filamentary article curled about its longitudinal axis, super-cooling the article, and finally orienting it by stretching. The latex should preferably contain about 30-50 per cent by weight of the polymer and the majority of the latex particles should preferably have diameters in the range of about 700-2000 Angstrom units. In the example, a continuous coherent coagulum is prepared by metering a polymer latex containing 33 per cent by weight of a dispersed 97/3 w./w. vinylidene chloride/acrylonitrile copolymer on to a ceramic roll wetted with a 20 per cent aqueous calcium chloride solution. The coagulum is stripped continuously from the roll, washed with water to remove from it all the calcium chloride and dried by passage over a heated drum. The coagulum is then fed at a uniform rate of 20 feet per minute through a zone heated by two 100-watt per inch radiant heaters placed 0.75 inch from either side of the coagulum. The resulting filamentary article curled about its long axis is then passed around a chilled roll and finally between two pairs of snubbing rolls so as to impart a 4 : 1 stretch to the article. |
