Compounding requirements can be summed up as follows. The plasticizers and other constituents like stabilizers, additives, fillers, reinforcement materials and flame retardants are absorbed into the porous PVC grain and must be systematically gelled, dispersively and distributively mixed, and agglomerated in the compounding systems – all in compliance with well-defined temperature limits.
Additional property requirements can be achieved by alloying other polymers with PVC during the compounding process. Examples of this include the use of TPU with flexible PVC to improve abrasion resistance, as well as oil and flame resistance. PVC and Nitrile Rubber blends improve low temperature flexibility and chemical resistance. PVC with nitrile rubber or TPU can be alloyed to improve hot melt strength got medical applications, as well as abrasion resistance and durability. PVC/EVA provide reduced plasticizer volatility and improved chemical resistance, while PVC/CPE provides improved compression set and low temperature flexibility.
The Buss Kneader can make the most of its strengths profile at uniform, moderate and if necessary adjustable shear rates. Free capacities along the processing axis are designed and realized according to requirements. Low specific energies with the most intensive mixing processes, volumetric scale-up procedures, and maximum availability are possible due to wide operation windows. These are the advantages that underline more than sixty years of technological and market leadership in compounding plasticized PVC.