HT-759 Rubber Compression Set Tester

Application

The rubber compression set tester compresses a sample of known height to a specified height according to the compression rate requirement, maintains it for a certain time under specified temperature conditions, then releases the compression, restores the sample to a free state, and measures the height of the sample.

The compression set tester consists of parallel steel plates, limiters and fasteners. It is used to measure the deformation of vulcanized rubber, thermoplastic rubber or foam at room temperature, high temperature and low temperature conditions, at a certain compression rate and after a certain compression time.

Standards

ASTM D395 - 03 Standard Test Methods for Rubber Property—Compression Set

ISO 815-1 Determination of compression set of vulcanized rubber or thermoplastic rubber Part 1: At room temperature and elevated temperature

GB/T 7759.1 Determination of compression set of vulcanized rubber or thermoplastic rubber Part 1: At room temperature and elevated temperature

Technical Parameters:

1. Limiter height:

(1) Type A specimen diameter 29mm, height 12.5mm

9.3～9.4 when compression rate 25%

10.6～10.7 when compression rate 15%

11.25～11.35 when compression rate 10%

(2) Type B specimen diameter 13mm, height 6.3mm

4.7～4.8 when compression rate 25%

5.3～5.4 when compression rate 15%

5.65～5.7 when compression rate 10%

2. Dimensions of rubber permanent compression deformation tester: width 120mm, length 200mm

3. Weight: about 15Kg

Principle:

A sample of known height is compressed to a specified height according to the compression rate requirements, maintained at a specified temperature for a certain period of time, and then the compression is released, the sample is restored to a free state, and the height of the sample is measured.

Testing procedure:

1. The sample should be treated at (23±2)℃, (50±5)%RH for 24h.

2. Measure the original thickness of the sample, accurate to 0.02mm.

3. Put the sample into the instrument, place the pad corresponding to the sample type, and lock the instrument. It can be carried out at room temperature.

4. After clamping the sample, it must be placed in an oven with set temperature within 2h.

The test temperature and time refer to the standard or are specified by the customer. For example, ASTM D1349-99 has: -75℃, -55℃, -40℃, -25℃, -10℃, 0℃, 23℃, 40℃, 55℃, 70℃, 85℃, 100℃, 125℃, 135℃, 150℃, 160℃, 175℃, 200℃, 225℃, 250℃.

The recommended test time for the rubber compression deformation tester is 22h and 70h (SGSin house method).

5. After the test time is over, immediately remove the instrument from the oven and remove the sample.

Place the sample on a poor thermal conductor such as a wooden board and cool it at (23±2)℃, (50±5)%RH.

6. After cooling for 30 minutes, measure the thickness of the sample again.

Results Calculation:

C = [(To-Ti)/(To-Tn)] ×100%

C——Compression deformation, %

Tn——Thickness of pad, mm

To——Thickness of specimen before test, mm

Ti——Thickness of specimen after test, mm