Forming a composite extrusion
Forming a composite extrusion
Keyword: Forming technologies
Applicant: Schlegel (UK) Holdings Limited, Seacroft, GBPatent number:US6,024,906Publication date: 15 February 2000Title: Method for forming a composite extrusion
The present invention seeks to provide methods of manufacturing composite extrusions which are suitable for use as a door or boot seal in the motor industry or as a seal or window channel either in the building or motor industry, or for other purposes and which is principally formed of a vulcanised polymeric material (thermosetting polymeric material). This material is considerably less expensive than the majority of suitable thermoplastics polymeric materials (plastics). The invention makes it possible to produce a wide range of extrusions relatively cheaply but which can either have surface properties of the more expensive extrusions formed of thermoplastic material and which can have its properties changed without having to incorporate a metal carrier in the extrusion.
A method of forming a composite extrusion is disclosed where a main body portion of the extrusion is first extruded from a thermosetting material. This main portion is then heated partly to cure it and then passed at high temperature through a further extruder where a thermoplastics material is extruded onto one or more surfaces of the main body portion. The subsequent composite extrusion is then cooled and formed into its final shape. It is important that the combining step be undertaken at a temperature high enough to cause the thermoplastics material to bond to the thermosetting material. The thermoplastics material may be of a special color, may be embossed, and if it is located within the thermosetting material in the end product, may be stiffer than the latter.
