| 摘要 |
<p>1,226,726. Spinneret for producing bifilament yarn. ALLIED CHEMICAL CORP. 4 June, 1969 [9 July, 1968], No. 28355/69. Heading B5B. A spinneret for producing bifilament yarn from a molten linear synthetic polymer comprises an extrusion plate 36 having an orifice arrangement 30 comprised of a pair of holes 32 and 34 extending parallel to each other through the plate and separated by a web structure 38 of thickness not more than 0À01 inch, the web structure being undercut at 40 approximately 0À002 to 0À008 inch to improve the coalescence of separate streams of molten polymer extruded through the holes. The holes may be of different sizes, as shown, or of the same size; in the former case the larger hole has preferably a diameter at least twice that of the smaller hole. The width of the web undercut is from 0À005 to 0À03 inch depending on the hole diameter; smaller holes have an undercut width equal to their diameter, whilst larger holes (e.g. 0À04 inch diameter) have an undercut width less than their diameter. The web thickness is preferably from 0À002 to 0À006 inch. The extrusion plate may have a countersunk portion on the inner face to reduce the length of the holes. The separate streams of molten polymer coalesce immediately prior to leaving the extrusion plate, and good coalescence is obtained.</p> |
