Process and apparatus for widening thermoplastic film webs

摘要

The invention is used for widening film webs prefabricated by roll forming or extrusion forming. The aim of the invention, to reduce the outlay and ensure a high quality of film altered in width after its production, gives rise to the object of widening prefabricated film webs with little strain and without adversely affecting its microstructure and the strength values. The way in this is achieved envisages that a film web moved in alternating roll contact is to be deflected one or more times through an angle of 0@ to 60@ in a horizontal plane diagonal to the direction of web movement in the state of plastic deformability at a temperature of 170@C to 100@C , so that after the deflection the web has a speed and width which correspond to the general conditions for retaining the surface constancy while approximately maintaining the original film thickness. IMAGE