BS ISO 289-2:2020 pdf free.Rubber, unvulcanized – Determinations using a shearing-disc viscometer.Determination of pre-vulcanization characteristics.
BS ISO 289-2 1 Scope This document specifies a method for determining the pre-vulcanization characteristics of compounded rubber. The pre-vulcanization characteristics determined by this method provide a means of estimating how long compounded rubber can be maintained at high temperatures and remain processable. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content  constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 289-1， Rubber, unvulcanized 一Determinations using a shearing-disc viscometer 一Part 1:  Determination of Mooney viscosity.4 Principle The test consists of determining how the Mooney viscosity of the rubber compound changes with running time at a specified temperature relevant to the process for which the compound is to be used. The time at which the Mooney viscosity has increased by a specified number of units is recorded. 5 Apparatus The apparatus specified in ISO 289-1 shall be used. It is permissible to use the small rotor for high- viscosity compounds.
6 Calibration schedule See Annex A. 7 Preparation of test specimen Prepare the two discs comprising the test specimen from a sheet of rubber compound, using the procedure for preparation of test pieces described in ISO 289-1.  8 Test temperature Choose a test temperature relevant to the process for which the compound is to be used. 9 Procedure Use the procedure described in ISO 289-1. The pre-heating time shall be 1 min, and the test shall be continued until the viscosity reaches the specified number of units above the minimum. When a large rotor is used, the increase is specified as five units and when a small rotor is used, the increase is specified as three units. The corresponding pre-vulcanization times are designated ts and t3, respectively. A typical trace obtained with the large rotor is shown in Figure 1.BS ISO 289-2 pdf download.