| 摘要 |
1,175,019. Longitudinally patterned films. FMC CORP. 6 Nov., 1968 [11 Dec., 1967], No. 52510/68. Headings B5A and B5B. Longitudinally patterned films are made by delivering under pressure a continuous unbroken stream of flowable film-forming material through a nozzle 9 having a passage 17 and a continuous unobstructed discharge orifice so that the stream is unconfined only in its flow direction, obstructing the stream in a direction generally perpendicular to its flow by means of a series of spaced members 21 extending across the nozzle passage which divide the stream into a series of separate streamlined flows, the members being spaced from the nozzle discharge orifice at a distance sufficient to permit adjacent streamlined flows to contact and to blend only partially with each other within the nozzle, and setting the stream discharged to form a solid film 25, which is preferably stretched longitudinally. The members may be spaced at substantially equal intervals across the nozzle passage and/or may be spaced at substantially equal distances from the nozzle discharge orifice and are preferably of smooth streamlined contour, e.g. fine round wire. Plates or deflectors having a blade-like or tear-drop cross-section may also be used. The finished film 25 has grooves or score lines 27 which facilitate separating the film into tapes or ribbons. Materials which can be used are polyamides, polyesters, polyvinyl chloride, polyolefins, cellulose acetates, metals, glasses, natural or synthetic rubbers, viscose, cupro-ammonium cellulose or carboxymethyl cellulose. Additives such as stabilizers, dyes and foaming agents may be included. |
