Resources Contact Us Home
Method for the manufacture of biaxially stretched polyolefin film

Image Number 4 for United States Patent #4261944.

A method is disclosed for the manufacture of a biaxially stretched polyolefin film, particularly a polypropylene film, having improved properties, in which the material is first partially prestretched in a longitudinal direction and, thereafter, simultaneously biaxially (longitudinally and laterally) stretched, the apparatus comprising stretching rollers for effecting partial longitudinal stretching of the film, the rollers being arranged upstream of an assembly for effecting simultaneous biaxial stretching of the film. The speed of the stretching rollers is infinitely variable so as to influence the total degree of film-stretching only by changing the speed of the rollers. The rollers used for longitudinal prestretching are arranged at the inlet section of the biaxial stretching assembly. A system is provided to maintain the film exactly at the temperature required by the film characteristics for stretching, and biaxial stretching is done such that any given point on the film in the region the film is being biaxially stretched undergoes simultaneous biaxial stretching both in the longitudinal and transverse directions of the film.

  Recently Added Patents
Distributed IPv6 neighbor discovery for large datacenter switching systems
System for and method of providing single sign-on (SSO) capability in an application publishing environment
Load balancing in shortest-path-bridging networks
Wireless refrigerant scale platform
System and method for optimizing teams
Circuit board and display panel assembly having the same
Managing method and apparatus for servicing contents provided by content provider
  Randomly Featured Patents
Apparatus and method for forming a tubular frame member
Riding lawn mower
Method and apparatus for contour tracking of an image through a class of non linear filters
Lap joint between flex hose and rigid pipe
System architecture for improved network input/output processing
Combination extension and compression tool holder
Battery terminal connector
Count separator for a stream of overlapped articles
Method and article for teaching the core construction of the singularity motion
Door lock apparatus for a vehicle