Process and apparatus for producing uniaxially stretched articles difficult to split longitudinally

Abstract

Abstract A UNIAXIALLY STRETCHED TUBULAR FILM OF THERMOPLASTIC RESIN DIFFICULT TO SPLIT IN THE LONGITUDINAL DIRECTION IS PRODUCED FROM AN UNSTRETCHED TUBULAR FILM OF THERMOPLASTIC RESIN, BY A PROCESS IN WHICH SAID UNSTRETCHED TUBULAR FILM IS PASSED THROUGH A NIP OF FEEDING ROLL MEANS, THEN PASSED VERTICALLY DOWNWARDS THE OUTSIDE SURFACE OF A MANDREL WHILE ENVELOPING THE LATTER AND WHILE BEING HEATED FROM THE OUTSIDE, SAID MATDREL BEING SUSPENDED BY THE NIP OF TWO PARALLEL SETS OF MUTUALLY ABUTTING ROLL MEANS, AND THEN THE RESULTANT FILM IS DRAWN OUT BY A ROLL MEANS WHOSE PERIPHERAL SPEED IS GREATER THAN THAT OF FEEDING ROLL MEANS TO EFFECT LONGITUDINAL STRETCHING, AND IN WHICH SAID MANDREL HAS A PERIPHERAL LENGTH EQUAL TO OR SLIGHTLY SMALLER THAN THE PERIPHERAL LENGHT OF THE UNSTRETCHED TUBULAR FILM, THE INSIDE OF SAID TUBULAR FILM BETWEEN THE MANDREL AND THE DRAWN OUT ROLL MEANS IS FILLED WITH A GAS UNDER PRESSURE.

Inventors

• 👤 H Hino
• 👤 H Asakuno
• 👤 T Yamada

Bibliographic Details