Belt calender and method for manufacturing preimpregnated composites

A belt calender for manufacturing preimpregnated composites, comprising:

• a first roller, which is rotatable around its longitudinal axis;
• a first belt running at least partly around the first roller;
• and
• a second belt running in between the first roller and the first belt,
• wherein the first belt and the second belt are configured for guiding a feed of material between them,
• wherein a plurality of auxiliary rollers, which are rotatable around their respective longitudinal axes, are arranged substantially parallel to the first roller around at least a part of a circumference thereof,
• wherein the first and second belt and any material therebetween run in between two adjacent ones of the plurality of auxiliary rollers, thereby defining a meandering path for the feed of material,
• wherein the first belt, the second belt and any material therebetween runs, in a transport direction of the feed of material:
• alternatingly along the inside and the outside of two adjacent ones of the auxiliary rollers as seen from the first roller, and
• along the first roller, and subsequently along the auxiliary rollers, and
• wherein the first roller is a heated roller and has a diameter larger than the auxiliary rollers, such that the material between the first and second belts is preheated by the first roller and subsequently massaged by the auxiliary roller.