Rubber, unvulcanized - Determination of plasticity - Rapid-plastimeter method
WARNING 1 - Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to determine applicability of any other restrictions.
WARNING 2 - Certain procedures specified in this Document might involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies a method for the rapid determination of the plasticity of raw rubber and unvulcanized compounded rubber.
This document is applicable to the determination of the plasticity retention index (PRI) as specified in ISO 2930.
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 1795 Rubber, raw natural and raw synthetic - Sampling and further preparative procedures
ISO 18899 Rubber - Guide to the calibration of test equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
plasticity number
measure of plasticity, based upon the height of a test piece after being subjected to deformation under specified conditions of compressive force, time and temperature
4 Principle
A disc-shaped test piece is compressed rapidly between small parallel platens to a fixed thickness of 1 mm. The test piece is maintained at this compression for 15 s to enable it to reach approximate temperature equilibrium with the platens. After this period, the test piece is subjected to a constant compressive force of 100 N ± 1 N for 15 s. Its thickness at the end of this period is taken as the measure of plasticity.
