Ring and Ball Apparatus
Ring and Ball Apparatus is used to determine the softening point of bitumen, waxes, LDPE, HDPE/PP blend granules, rosin and solid hydrocarbon resins.[1] The apparatus was first designed in the 1910s while ASTM adopted a test method in 1916. This instrument is ideally used for materials having softening point in the range of 30 °C to 157 °C.[2][3][4]
Components
- Two brass rings.
- Two steel balls.
- Two ball guides to hold the balls in position.
- A Support to hold the rings, balls and thermometer in position
- A Glass beaker
- Thermometer
- Hot plate
- Magnetic stirrer
- Glycerol or water as heating bath
Procedure
The solid sample is taken in a Petri dish and melted by heating it on a standard hot plate. The bubble free liquefied sample is poured from the Petri dish and cast into the ring. The brass shouldered rings in this apparatus have 6.4 mm depth. The cast sample in the ring is kept undisturbed for one hour to solidify. Excess material is removed with a hot knife. The ring is set with the ball on top with ball guides on the grooved plate within the heating bath. As the temperature rises, the balls begin to sink through the rings carrying a portion of the softened sample with it. The temperature at which the steel balls touch the bottom plate determines the softening point in degrees Celsius.[5][6]
References
- ^ "When does tarmac melt?". BBC News. 2013-07-15. Retrieved 2020-04-17.
- ^ "Right Grade of Bitumen for Flexible Pavements: Indian Perspective". www.nbmcw.com. Retrieved 2020-04-17.
- ^ "CFR - Code of Federal Regulations Title 21". www.accessdata.fda.gov. Retrieved 2020-04-17.
- ^ US 7847011, Kitson, Ralph P., "Intermediate softening point resin-based hot melt PSAs", published 2010-12-07, assigned to Avery Dennison Corp.
- ^ "Ring and ball test apparatus for Softening Point of Bituminous material. Cement Concrete". Cement Concrete. 2019-08-16. Retrieved 2020-04-17.
- ^ Walker, P. H. (1930). The ring and ball method of test for softening point of bituminous materials, resins, and similar substances. NIST Research Library. National Bureau of Standards.