MANUFACTURE OF POLYMERIC TUBULAR FILMS

专利名称：MANUFACTURE OF POLYMERIC TUBULAR

FILMS

发明人：LEENDERT VAN ASSENDELET,BERTUS H.

ZANDSTRA

申请号：US3584656D申请日：19690214公开号：US3584656A公开日：19710615

摘要：1,266,921. Laminated tubular film. ALGEMENE KUNSTZIJDE UNIE N.V. 17 Feb.,1969 [17 Feb., 1968], No. 8485/69. Headings B5A and B5B. [Also in Divisions F2 and H1] Atubular film has a wall having at least three layers which are formed alternately ofdifferent polymers and which, as exposed in a transverse cross-section of the tubular film,have at least over part of the film's circumference a spiralling shape, the layers definingthe inner and outer wall surfaces being each formed of a single polymer. The spirallingpart of each layer may extend through an angle of at least 360 degrees. The thickness ofat least one of the surfacedefining layers may differ from, and may be at least 50%thicker or thinner than, any one of the layers of spiralling shape. To make such a tubularfilm in which the surface-defining layers consist of different polymers, two streams ofdifferent polymer are fed, Fig. 1, via adjacent passages 20, 21 respectively to annularchamber 14 between housing 3 and rotor 6. The streams, rotating side by side with rotor6, flow through chamber 14 and are extruded through an annular slot 17 to form the film30, Fig. 3. The outlets 25, 26 of passages 20, 21 are elongated in a direction parallel to theaxis of rotation of rotor 6. Alternatively, the two polymer streams may be fed into one

end of the annular chamber, one stream being eccentrically disposed with respect to thechamber's axis and being surrounded by the other stream, or two polymer streams maybe fed through a stationary mandrel to an annular chamber formed between themandrel and a rotatable housing surrounding the mandrel. To make a film in which thesurface-defining layers are formed of the same polymer, two streams of differentpolymers are fed, Fig. 4, into one end of an annular chamber between rotor 37 andhousing 39 via ports 40, 41 respectively. The two streams, one surrounding the other, arerotated and fed along the chamber to be extruded through an annular slot. Theextruded tubular films may be inflated.

申请人：ALGEMENE KUNSTZIJ DE UNIE NV.

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