| Abstract: | Calendering of rigid and semirigid PVC (and ABS) compounds require an understanding of compound rheology and critical processing parameters. Compound rheology is modified with processing aids and lubricants. The choice of processing aid can be critical to achieving the desired rheology needed for calendering. This paper will focus on defining calendering rheology parameters as a function of a super high molecular weight MMA/SAN copolymer processing aid. These rheology parameters will be defined in terms of mill roll gap pressure, adhesive force (compound roll release) melt temperature, and shear rate. The ability to measure these parameters via a computerized two roll mill and relate this data to the actual calendering line will also be discussed. |
