As we all know, there are many types of rubber products, and rubber of different materials is difficult to distinguish from the appearance. Some unscrupulous manufacturers took the opportunity to subdue the consumer. As a professional rubber manufacturer with a sense of responsibility, everflex will share with you several simple rubber material identification methods for your reference.
1. Combustion method
In general, fluorine rubber, CR, CSM are at a loss from fire, even if the flame is burning, it is much smaller than the general NR and EPDM. Of course, if you look closely, the burning state, color, and smell will give us a lot of information. For example, NBR/PVC is glued together. When there is a fire source, there is a splash of fire. It seems to have water. It is self-extinguishing from the fire, and the smoke is rich and sour. It should be noted that sometimes the flame retardant but halogen-free glue will also be self-extinguishing from the fire, which is further inferred by other means.
2, resistance to medium weight gain experiment
It can be sampled from the finished product, immersed in one or several selected media, and weighed after a certain temperature time, and the type of material is inferred according to the rate of change of hardness.
For example, immersing in 100 degree oil for 24 hours, NBR, fluorine rubber, ECO, CR quality and hardness change rate is small, while NR, EPDM, SBR gain more than double the hardness and the hardness changes greatly, the volume expansion is obvious.
3, hot air aging experiment
Sampling from the finished product, aging in an aging tank for one day, observing the phenomenon after aging. It can be graded and aged gradually. For example, at 150 degrees, CR, NR, and SBR are all brittle, and NBR EPDM is flexible. When it rises to 180 degrees, ordinary NBR will be brittle; at 230 degrees, HNBR will also be brittle, and fluorine rubber and silica gel still have good elasticity.
4, measuring specific gravity
Use an electronic scale or analytical balance, accurate to 0.01 grams, plus a glass of water, a hair can be.
Generally speaking, the specific gravity of fluorine rubber is the largest, 1.8 or more, and CR ECO is also more than 1.3. The specific gravity is obviously larger.
5, low temperature method
Sampling from the finished product, using dry ice and alcohol to create a suitable low temperature environment. The sample was soaked in a low temperature environment for 2-5 minutes and felt soft and hard at the selected temperature. For example, at -40 degrees, the same high temperature and oil resistance is very good compared with silica gel and fluorine rubber, and silica gel is soft.
The above identification methods are relatively convenient and easy. The comprehensive comparison and analysis of the results of various methods can basically delineate the general range of rubber materials. As a professional rubber manufacturer, everflex sincerely hopes that everyone can buy quality rubber products.