Vulcanized rubber TR test

As the temperature decreases, rubber will gradually lose its original characteristics, such as relaxation, increased hardness, loss of elasticity, and a series of other problems. The vulcanized rubber temperature retraction test (TR test) measures the retraction properties of stretched vulcanized rubber at low temperatures. The low temperature retraction (TR) testing machine (also called the low temperature tensile rebound testing machine) consists of a refrigeration system, a heating system, a data acquisition system and a data transmission system.
Zhongke Testing Reliability Experiment Center has the ability to test the reliability performance of various vulcanized rubbers and provides professional TR testing services for vulcanized rubber.

In terms of its vulcanization method, vulcanized rubber can be roughly divided into:
1) Flat vulcanizing machine vulcanization: flat tapes such as conveyor belts and transmission belts;
2) Vulcanizing tank vulcanization: rubber hoses, rubber rollers, rubber shoes, air bags, rubber strips, tapes, roller coatings, pipe linings, cables, etc.;
3) Continuous vulcanization: sealing strips, pure rubber hoses, wires and cables, etc.

1. The specimen is stretched at standard laboratory temperature and then cooled to a temperature low enough that no retraction occurs when the tensile force is removed. The tensile force is removed and the temperature is increased at a uniform rate. Measure the temperature when the specified shrinkage rate is reached.
2. Select liquid or gas heat transfer media according to the requirements of ISO 23529. It should maintain a fluid state at the test temperature and have no obvious impact on the material being tested.
If the test instrument can ensure that the test results are the same as those using liquid heat transfer media, gas heat transfer media can also be used. The following fluids can be used:
a) When the test temperature is as low as -60 ℃, silicone oil because it is chemically inert, non-flammable and non-toxic to rubber;
Note: The kinematic viscosity at ambient temperature is approximately 5 mm2/s.
b) When the test temperature is as low as -73 ℃, ethanol;
c) When the test temperature is as low as -120°C, methylcyclohexane is cooled with liquid nitrogen (applicable to supporting instruments).

GB/T 7758-2020 Vulcanized rubber - Determination of low temperature properties - Temperature retraction procedure (TR test)
ISO 2921:2019 Vulcanized rubber Determination of low temperature properties Temperature retraction procedure (TR test)
ISO 18899: 2013 Rubber Test Equipment Calibration Guide
ISO 23529 Rubber Physical test methods General procedures for specimen preparation and conditioning