How to identify epdm seal?

Actually in door window actual production process, the investment that seals strip holds proportion is very small, but its action cannot ignore however. Such as waterproof, sealing and energy saving, sound insulation, dustproof, antifreeze, heat preservation, temperature resistance, aging resistance, these functions in daily life are not to be ignored. So how do you tell?

1. Smell whether there is any peculiar smell through the nose, normally there is a little bit of ethanol smell, but hardly any smell;

2. The sealing strip as tight as possible wrapped in the profile, placed in high temperature for a period of time (on the roof or sufficient sunlight), to see whether the surface of the profile and the contact surface of the seal strip stain discoloration, whether the surface of the seal strip dust yellow (oil is easy to absorb soil) oil infiltration, whether dirty hands;

3. Some cheap sealing strip filler will be a lot, so the surface will not be very bright, those very cheap appearance is not desirable;

4. Look at the specific gravity, add the heavy calcium seal strip, stretch back and forth by hand for several times, the surface will appear a small amount of white powder, especially poor quality or even casually pull on the break.