Abstract: A profile strip, especially suitable for the production of window or door frames, has an optionally hollow core profile made from a glass fiber-reinforced PVC composition and a shell made from a synthetic resin compatible with PVC and exceeding the impact resistance of the core profile.

Abstract: A glass fiber-reinforced polyvinyl chloride composition contains, per 100 parts by weight of polyvinyl chloride of a K value of between 55 and 75, 40-100 parts by weight of glass fibers having a diameter of between 5 and 25 .mu.m with a length of 0.5 to 12 mm, and 1-25 parts by weight of mineral filler having an average particle diameter of below 50 .mu.m.

Abstract: A process for preventing separation of fillers and other dispersed additives from thermoplastic molding compositions during extrusion, calendering or like processing, along metallic contact surfaces of a processing unit, involves admixing a silane additive to a portion of a thermoplastic molding composition containing a thermoplastic molding resin and at least one filler or other dispersed additive that tends to separate out from the molding composition during the processing, processing the portion of thermoplastic molding composition in a processing unit, measuring the electrical energy applied to the processing unit during processing per kilogram of molding composition per unit time, determining if the electrical energy applied has been increased by the addition of the silane additive as compared to the electrical energy required per kilogram of molding composition per unit time for processing another portion of the thermoplastic molding composition free of the silane additive and thereafter adding an effec