Equipment Overview:

The machine is energy 0.5J /1J pendulum-type impact testing machine flexibility for nominal hardness 30-85IRHD rebound between the value of vulcanized rubber.

To meet the standards:

This is in line with GB / T 1681 “Determination of vulcanized rubber elasticity” and the requirements of ISO4662 standards.

Applicable industry:

Rubber

Technical parameter:

Test Procedure

1. Sample preparation 

Sample preparation and specimen size use a test piece with a thickness of d = 12mm and a diameter of 29 mm to 33 mm. The test sample should be vulcanized or cut directly from the finished product. Pay particular attention to the smooth and planar parallelism. Some talcum powder should be puffed slightly if the hammered surface is tacky. If a specimen of the required thickness cannot be obtained from a finished product, the specimen can be stacked, but a maximum of three pieces can be stacked. The stack can only be used for test samples that are parallel in the plane or equal in thickness across the entire surface. Samples must not contain fabrics or other reinforcing materials. If the surface is not uniform, it should be ground using DIN ISO 4661-1.

Note: When the sample thickness is thin, the sample will be affected by the stiffness of the anvil and its deformation; this can only get a small rebound value. An ISO/TC 45/WG 5 working group conducted an international comparative test in 1970. The difference in elasticity between 2 mm and 12 mm thickness was 2 to 6 %. This difference depends on the thickness of the elastomer, and for extremely soft elastomers, the difference is greatest.

2. Number of samples

At least two specimens.

3. Pretreatment of Samples

The test should be carried out at least 16 hours after vulcanization but not later than four weeks. At least for the last 3 hours of this period, the sample should be parked at a temperature of 23 ± 2 °C. For finished products, the time between vulcanization and the start of the test should not exceed three months. Otherwise, the test should be carried out within two months after delivery to the user.

4. Test procedure

After the sample was placed on the fixture on the anvil and the temperature was adjusted, the pendulum was dropped from the horizontal position to the same position on the sample for a total of 6 drops. Hold the sample before each impact. The first three shocks were used to adjust the specimen mechanically and read the resilience values of the fourth, fifth and sixth times. Take the value from three readings.

5. Evaluation

The median value is obtained from the three single measurement readings rounded off to integer percentages. The arithmetic mean of the resiliency R is calculated from the median of at least two specimens.