What material should the rheometer barrel be made of?
The standard barrel is made of nitrided steel for hardness and toughness. Barrels from other materials may be required where the samples adhere to the steel making cleaning difficult e.g. PES and PEEK, where a sterile environment is required e.g. pharmaceutical and food, or where the sample may corrode the steel or degrade to produce corrosive products. Malvern can provide a chart of recommended barrel material for most commonly encountered polymers. Alternative choices of materials for the barrel are Hastelloy for PES, PEEK, and other corrosive materials, and stainless steel for pharmaceuticals, food products or other aqueous substances.
