Swell And Shrinkage Tests

Swelling of rubber (or other elastomer) gaskets, or seals, when exposed to petroleum, synthetic lubricants, or hydraulic fluids. Seal materials vary widely in their resistance to the effect of such fluids. Some seals are designed so that a moderate amount of swelling improves sealing action. Refer to Swell and Shrinkage Tests. 

Polymer designers need to focus on processing performance as quite often polymer grades designed for particular applications or parts often fail due to poor processability. Swell and shrinkage tests can be considered fundamental tests that should be run as a qualitative assessment of processability. 

There are numerous other experimental methods that provide information about the rheological behaviour, including the molecular response to stresses and strains swell and shrinkage tests, flow-birefringence measurements (Chapter 9) and flow-infrared-dichroism measurements (Chapter 9) to mention but a few. 

The moisture content of the paper has a strong effect on the folding endurance test. The swelling and shrinkage which accompany adsorption and desorption of water vapor cause shifting and rearrangement of... 

Rheological test more often used for product quality control is a measurement of the elastic recovery in polymer melts and their compounds. This is usually accomplished by measuring the swell (or shrinkage) of materials undergoing extrusion. The tendency of polymers, whether thermoplastic or rubber, to enlarge when emerging from an extruder die is called die swell. 

At this stage, it is appropriate to mention a method which determines a transition temperature for a wide range of collagens which in turn correlates closely with Tjy measured on dilute neutral solutions. It is simply the force-temperature method already discussed except that the sample is first soaked in HCl at pH 1 and tested in this medium. As is well known, the sample will swell reversibly in this medium at low temperatures. When the system is now heated a shrinkage phenomenon occurs that is quite analogous to that which takes place in saline at T. ... 

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