Method of making a dimensionally stable tube type plastic heat exchangers

摘要

Plastic tube-type heat exchanger structures are made with partially crystallized partially aromatic polyamides of high glass transition temperature. The structures are then annealed to further crystallize the polyamides, causing shrinkage and building up residual tensile stresses. These stresses counteract the swelling caused by water absorption and temperature rise during use of the heat exchanger and keep the structures dimensionally stable.