ISO 815-2:2019 pdf free

ISO 815-2:2019 pdf free.Rubber, vulcanized or thermoplastic一Determination of compression set
A test piece of known thickness is compressed at standard laboratory temperature to a defined strain,which is then maintained constant for a specified time at a fixed low temperature. The compression is totally released and, after the test piece has been allowed to freely recover at the same fixed low temperature, the thickness of the test piece is again measured.
A test piece of known thickness is compressed at standard laboratory temperature to a defined strain,which is then maintained constant for a specified time at a fixed low temperature. The compression is released and the test piece is allowed to recover at this temperature under a given pressure according to ISO 23529 for thickness measurement. The thickness is measured either at intervals after the release of the strain (so that an assessment of compression set characteristics can be obtained by plotting of recovery against time at the low temperature) or a specified time after the release of the strain.
Low-temperature cabinet, capable of maintaining the compression apparatus and test pieces at the test temperature within the tolerance limits specified in 8.2. The low-temperature cabinet can be mechanically refrigerated or it can be cooled directly by dry ice or liquid nitrogen.
The cabinet shall be designed so that it is possible to release the test pieces and carry out the subsequent thickness measurements without direct contact, e.g. by means of hand-holes fitted with gloves or a remote-handling device. The cabinet shall be capable of maintaining the temperature within specified limits while these operations are being carried out.
The time to reach a steady-state temperature depends on the type of cabinet and the overall heat capacity of the compression apparatus. To obtain test results which can be compared with each other,it is necessary, in the case of a 24 h test duration, to reach the steady-state temperature within the specified limits in the interior of the test pieces in not more than 3 h. ISO 815-2 pdf free download.