Acrylic process aids for PVC: From theoretical concepts to practical use

Acrylic process aids have been widely used for decades in the production of both rigid and flexible PVC materials. Their advantages are well‐known and are briefly reviewed in this paper. Excessive use of process aids or selection of the wrong molecular weights may, however, lead to undesirable behavior ultimately resulting in defects in PVC materials. These limitations are discussed in detail and explained on the basis of general polymer science considerations. Some criteria to optimize the proper selection of the level and nature of the process aids in PVC formulations are given in relation to the final applications, such as films, window and foam profiles, pipes, and so on.