| 摘要 |
<p>999,072. Melt-spinning synthetic filaments. BRITISH NYLON SPINNERS Ltd. Jan. 9, 1964 [Jan. 25, 1963], No. 3197/63. Addition to 901,398. Heading B5B. The melt spinning process of the parent Specification (wherein there is continuously and uniformly provided immediately below the spinneret plate a homogeneous and laterally unconfined shallow layer of an inert gas, such as superheated steam, in contact with the entire surface area of at least that portion of the face of said spinneret plate which contains the extrusion orifices) is modified in that the layer of gas is provided by two streams of gas emanating from opposing sides of the face of the spinneret plate, the width and direction of each such stream being such that that part of the spinneret plate containing the orifices is blanketed with the gas. As shown in Figs. 1 and 2, a pack and spinneret assembly comprise two inwardly-facing elongated slots 1, 2 to each of which superheated steam is provided under pressure, the slots being located in flanges parallel to and contiguous with the long straight sides of the spinneret 3 of a " datebox " pack 4. The slots extend outwardly in their length direction to points beyond the short convex ends 5, 6 of the spinneret, in order that the outer orifices at those ends shall be completely blanketed with steam. The " datebox " pack comprises a pack holder 10 and a lid 11, filtering material 13 held between top screen 14 and spinneret screen 15, and a spinneret 3 mounted on a shoulder at the bottom of the holder. The steam from a supply pipe 16 is supplied to the slots 1, 2 by drillings 8, 9 formed in the lid 11 and the pack holder 10. Baffle means 17, 18 are positioned at the location where the drillings open into the slots, in order that the steam shall flow along the length of the slots in both directions, before flowing out of the slots across the face of the spinneret. Screw-threaded rods 19, 20, as steam diffusing means, are fitted in the lips of the slots 1, 2 and cause the steam to be evenly distributed along the full length of each slot. The helix angle of the screw of the rods is preferably a low one. If diffusing means are omitted from the slots 1, 2 the steam provided in the vicinity of the spinneret plate must have expanded to atmospheric pressure or must have been pre-diffused prior to its arrival in the slots, to fill them uniformly.</p> |
