METHOD FOR CONTINUOUS PMI FOAM PRODUCTION

摘要

The present invention relates to a method for continuous production of PMI foam blocks. The method has a high level of flexibility regarding the size of the blocks. Individual pre-polymerized PMI blocks are first joined to one another at their end faces, preferably by means of butt welding with heat reflectors, and then moved into an NIR heating station. There the PMI polymer foams up continuously while passing through the station. The PMI foam exits at the end as continuous material and can be cut or sawed into individual pieces of any desired length and shape. The advantage of this method in addition to the continuous method is that the PMI foam material is nearly strain-free and has a very uniform, closed-cell pore structure. This is accompanied by a uniform density distribution across the thickness of the block, since the foaming process does not proceed from the outside towards the centre of the block, but rather the polymer is subjected uniformly to the volume expansion.