US 5,729,878 AGranted

Web spreading apparatus

AssigneesNippon Petrochemicals Company, Limited, Polymer Processing Research Instr., Ltd.

InventorsKazuhiko Kurihara, Hiroshi Yazawa, Yuki Kuroiwa, Shuichi Murakami

Life of this patent

Estimating the term…

Loading patent…

Abstract

A web spreading apparatus for transversely spreading a web, such as a split web formed of a longitudinally uniaxially stretched film, includes a spreading means arranged in a travelling path of the web for transversely spreading the web. The spreading means comprises a curved rod-like member and projections arranged generally circumferentially about an axis of the curved rod-like member. The curved rod-like member is arranged so that the concave side is directed forward and the convex side is directed rearward, in the web travelling direction, and the projections are rotatable about the axis of the curved rod-like member at a speed higher than the travelling speed of the web. In one aspect, the curved rod-like member comprises a curved shaft and an outer tube arranged about the curved shaft and rotatable relative to the curved shaft, the projections being formed between the grooves cut on the outer tube. In another aspect, the projections are formed of a spring arranged about the curved rod-like member.

Claims16

Dependent claims

A web spreading apparatus for transversely spreading a web so that the width of the web after spreading is equal to or greater than 1.2 times the width of a web before spreading, said apparatus comprising:

conveying means for conveying the web along a predetermined conveying path;
tension control means for controlling tension of the travelling web;
spreading means arranged in the conveying path for transversely spreading the web;
said spreading means comprising a curved rod-like member having a concave side, a convex side and an outer circumference surface, and projections arranged generally circumferentially about an axis of the curved rod-like member;
said curved rod-like member being arranged so that the concave side is directed forward and the convex side is directed rearward, in the web travelling direction;
at least said projections being rotatable about the axis of the curved rod-like member at a speed higher than a travelling speed of the web;
and
said spreading means being arranged such that a spreading distance from a spreading-starting point to said spreading means is equal to or more than two times of the width of the web after spreading.

5 more elements

Dependencies are inferred from the claim text.