Resilience of polyurethane foam is determined by dropping a metallic sphere on a slab of foam kept on a horizontal surface from a height of 500 mm and finding the height to which it rebounds after striking the surface of foam. The Ball Resilience Tester for polyurethane foam consists of a flat horizontal platform, a vertical acrylic tube in which the sphere is dropped, and a hand operated arrangement to release the sphere from a pre-determined height. The acrylic tube is held over the base with the help of a holding block, which can be moved vertically to adjust the height of the tube to enable test specimens of different thicknesses to be tested. This adjustment is carried out with the help of a screw so that the height of the tube can be precisely set. The tube is held firmly after adjustment so that it does not rock during the test.
- The scale used for measurement of the height of rebound is marked on the outer surface of the acrylic tube. It ranges from 10% to 90% of the dropping height.
- The metallic sphere is kept in a circular opening in the metallic cover of the acrylic tube. It can be release by pressing a spring-loaded support, which is so designed as to release the sphere without imparting any initial linear or rotary movement to it.
- The equipment is finished in grey hammertone stoving painting and bright chrome plating to give it a corrosion resistant finish.
|Diameter of steel sphere||16 mm|
|Weight of steel sphere||16.3 g|
|Dropping height||500 mm|
|Height of test specimen||50 to 150 mm|
|Inner diameter of acrylic tube||40 mm|