Performance test methods for silicone rubber products
Jan 19, 2020
After the production of silicone products is completed, the product performance will be tested. If you want to select high-quality silicone products, you must master certain product performance test methods. As a professional manufacturer of silicone tube, let's popularize what tests are usually used to check the performance of silicone products.
Common performance tests of silicone rubber products include the following:
1, pull test
Tension is the main functional standard of silicone rubber products. For example, if the silicone material loses the tensile effect, then the product is basically equal to aging.
Testing methods for silicone products
1. Measuring tool: tensile testing machine
2. Measurement speed: 450MM / MIN?
3. Measurement specifications: Special cutting knife for tensile test (type 1), thickness 2.0 ± 0.2MM
4. Measurement method: mark a distance of 2.5CM in the middle of the parallel part of the sample, and this mark (width ≤0.5MM)
It will not affect the test results; open the switch of the tensile machine and the test software, clamp the two ends of the piece to be tested, and clamp the sample so that the longitudinal axis of the sample coincides with the center line of the upper and lower fixtures; Suitable to prevent the sample from slipping and breaking in the fixture; save the results after the test
2, temperature resistance test
Temperature test is the main problem of whether cracks, aging and other phenomena will occur in the use of silicone rubber products and high and low temperature conditions. Generally, the temperature resistance of silicone products has no effect between -40 ° C and 280 ° C. Silicone rubber materials The storage temperature is no problem between -15 ℃ and 100 ℃. The test method can be tested by high-temperature baking or low-temperature refrigeration.
3, size test
Size is a problem that affects the assembly of silicone products. Therefore, the size problem needs to be controlled in the internal mold and design of the silicone rubber product manufacturer. Generally, silicone rubber materials have a certain degree of flexibility. It is impossible to achieve 100% accuracy, so there will be The dimensional error of 0.1mm-0.3mm, if you want to completely control to a high precision size, no silicone manufacturer can guarantee, so the size of the test silicone product is usually ± tolerance range is about 0.3mm.
4. Odor test
Food grade silicone products are mainly used as living utensils. The odor and volatile substances in silicone products can have a certain effect on VOC detection and certification. Therefore, the odor test is usually a VOC test method. Put the silicone product in the oven and bake it. The weight of the volatile matter is measured afterwards.
The hardness of silicone products is usually divided into 30-80, and the normal use of hardness has a corresponding impact on different products. For example, the high hardness of the sealing silicone ring may lead to insufficient life, and the hardness is too low, resulting in poor sealing performance.
After making the hardness particles according to the above conditions, the hardness test cannot be performed immediately. The hardness test needs to be placed at room temperature and allowed to cool naturally. The specific test method is as follows:
1. Place the hardness particles flat on the table to ensure that the measured surface is horizontal;
2. Take the thorn needle at the bottom of the dial of the Shore A hardness tester and vertically align the back side of the hardness particle;
3. Apply a force of 1 kg to the Shore A hardness tester and press the hardness particles at a speed of 150 px / s. In order to ensure the accuracy of the test, it is best to make a test stand for the hardness tester and install the hardness tester on the support for hardness. Test
4. After the dial of the hardness tester stops, read the value pointed by the pointer and record it. At this time, the hardness test of the high temperature vulcanized silicone rubber (HTV) is completed.
6. Shrinkage and water resistance test
Compared with rubber and plastic foam products, the shrinkage rate of silica gel is relatively small. Generally, the shrinkage rate is 0.0012, the density is 1.3, and it can reach the standard without any dimensional change after soaking in water for 20 hours. In the case of mold making, silicone product manufacturers will add the shrinkage of silicone products to the mold to keep the product size unchanged.
1. Test quantity: according to the ratio of three to one?
2. Test method: Under normal lighting conditions, visually inspect the appearance quality and color of the product. Measure to the standard size of the drawing.
3. Test Standard:
The product has no cracks, bubbles, impurities, lack of materials, no burrs, and has the unique luster of silicone rubber products.
The surface of the product must not appear yellow or white.
The appearance color of the product must not be significantly different.