abstract |
A novel process and novel apparatus for producing prestretched plastic film is presented. The method and apparatus are capable of forming a film from molten material and cooling the film to a non-molten condition so the film can be stretched. The cooled film is engaged and passed through a primary nip and second nip to plasticly and elastically stretch the cooled film to cold orient the film such that the film is stretched beyond the material's yield point. The cooled film is engaged with a plurality of idler rollers at a relatively low tension over a distance sufficient to allow the cooled film to relax to recover a major portion of its elastic deformation. Thereafter, the film is formed into a roll prior to being affixed to a unit. |