Patent ID: 6890633

Claim:
A preform for sheets, made from a mixture composed of fibers and/or pellets made from cellulose or from wood and at least one hot-curing resin, produced by a process comprising the steps of (a) mixing from about 50 to about 90% by weight of fibers and/or pellets with from about 10 to about 50% by weight of hot-curing resin, where each of the percentages by weight is based on the total weight of the mixture, (b) kneading and homogenizing the mixture made from fibers and/or pellets which break down to nave fibers, and from at least one hot-curing resin, and passing the mixture onward to an extruder, (c) heating the mixture in the extruder to an extruder exit temperature at which the resin begins to cure, (d) extruding the mixture, which has not entirely cured, as a homogeneous composition and distributing the homogeneous composition within a calender line, (e) exerting pressure onto the homogeneous composition in the calender line, to an extent which gives a mat which is a preform, and (f) removing the preform and stabilizing its desired shape.