In order to achieve a homogenous melt when processing rigid PVC, the PVC matrix has to be broken down and the powder grain has to be split into primary particles. This process is improved by the use of acrylic processing aids. Since the particulate structure of PVC essentially determines the rheology of the PVC melt, acrylic processing aids are able to control the fusion of the PVC and to ensure the formation of a homogenous melt. DEGALAN® processing aids are acrylate co-polymers which are highly compatible with PVC with a molecular weight that exceeds 1,000,000 g/mol. These polymer chains enhance internal friction and heat transport between the PVC particles. In addition, acrylate processing aids create intensive friction between the PVC melt and metallic surfaces, thus improving energy influx. The targeted use of acrylate processing aids allows processors to control and influence the homogeneity, viscosity and elasticity of the PVC melt, as well as its plastification and gelation. All of these are key factors in PVC processing and prerequisites for finished products of consistently high quality. Processing aids can therefore be used to optimize dimensional stability, surface quality, impact strength and processing latitude.