Textured pattern on one surface of thermoplastic film - by expanding plasticised material into depressions of embossed foil

摘要

A synthetic film, consisting pref. of thermoplastic material, is heated to its plasticising point and fed through a calender having two smooth surfaced bowls. Simultaneously, pref. metal foil, which has been previously given an embossed patterned surface, is fed through the hot film. The relief pattern is brought into contact with the hot film and the two are highly pressed together. The hot film is thus able to fill the cavities of the relief patterned foil completely, whilst the heat is being dissipated, and the thermoplastic film is given a textured surface. The previously embossed band of material may consist of a film of thermosetting resin which has been given a thin metal layer. In the process, a thermoplastic resin may be melted to a fluid with a uniform viscosity and extruded through a broad slot nozzle as a thermoplastic film in the plasticised condition, and textured directly. The calender has two internally cooled rollers. The one coming into contact with the embossed band is surfaced with rubber, whilst the other cover which the plasticised film moves has a polished metal surface. The process applies the textured pattern to one surface only so that the film can be used for coating purposes more sucessfully. Temp. and pressures used cannot damage the thin pressing plate of Al foil or synthetic material, and the relief is applied by using the heat of the extruded material.