Rheology as a tool for quality control

Rheological properties are sensitive to certain characteristics of molten polymers that are subject to fluctuation during their manufacture. For this reason, rheology is widely used for quality control in the plastics industry. In selecting a rheometer and type of lest, The factors that must be considered include the nature of the polymer, the skill of the operator, the time available for testing, the cost of the rheometer, and the precision required, In setting up a lest protocol, care must be taken to ensure the continued reliability of test results. The selection of an instrument and the quantity to be measured depends on the characteristic that is to be tracked. This may be molecular weight, molecular weight distribution, degree of reaction, or tile concentration of an additive. Instrumentation varies from a manually operated melt indexer, with a cost of $ 5,000, to a dynamic analyzer or on-line rheometer that can cost up to $ 100,000.