The most common type of magnetic rubber products is the cold storage door sealing strip; since the magnetic sealing strip is mostly used in doors, refrigerator doors, cold storage doors, or exposed to the outside for a long time, or under low temperature conditions, the rubber compound used is Weather resistance and aging resistance are high, but the price of EPDM rubber that meets the performance requirements is high, and the low-priced, stable-performance EPDM reclaimed rubber is used to replace the EPDM rubber to produce magnetic sealing strips. Ideal raw material.
Compared with ordinary sealing strips, the biggest difference between magnetic EPDM sealing strips is the need to add magnetic powder. The type and amount of magnetic powder directly affect the performance of EPDM magnetic sealing strips.
1. Common magnetic powder types in magnetic EPDM sealing strips
Magnetic powder is a hard magnetic single-domain particle. The high-quality magnetic powder has complete crystal structure, smooth surface, uniform particle size and stable performance. The magnetic powder materials commonly used in EPDM strips are mainly ferrite materials, such as barium ferrite and antimony. Ferrite and barium ferrite are better used in EPDM reclaimed rubber strips.
2. Factors related to the magnetic magnitude of the magnetic EPDM sealing strip
The magnetic EPDM sealing strip loses its use value if the magnetic force is too small during use; the EPDM reclaimed rubber sealing strip with magnetic powder should be magnetized in the magnetic field, and the magnetization retention of the rubber after magnetization is increased. High, the larger the magnetic attraction of the EPDM seal, the longer the magnetic force can be maintained. Vulcanization is an important factor affecting the magnetic force of EPDM strips. Studies have shown that the magnetic retention strength of EPDM regenerated rubber after vulcanization is higher than that of unvulcanized rubber; the amount of magnetic powder can directly affect the magnetic strength of EPDM reclaimed rubber strip. Increasing the amount of rubber powder can significantly increase the magnetic force of the magnetic sealing strip.
3. Influence of the amount of magnetic powder in the magnetic EPDM sealing strip on the physical properties of the strip
EPDM rubber has a low density and can maintain high mechanical strength under the premise of filling a large amount of rubber oil or inorganic filler. In theory, it can fill a large amount of magnetic powder; but in actual production, if it is in EPDM magnetic strip If the amount of magnetic powder is too large, the physical and mechanical properties of the rubber compound will be significantly reduced. The EPDM reclaimed rubber is used as a product of recycling and reprocessing of EPDM rubber and waste EPDM rubber products, and contains a certain amount of filler. And rubber oil, so the amount of magnetic powder should not be too high; in addition, in the production of magnetic EPDM reclaimed rubber seals, rubber products companies can add 0.5-1.5% silane coupling agent or titanate coupling agent to alleviate the magnetic powder pair The influence of physical and mechanical properties of the strip can increase the amount of magnetic powder to a certain extent.
For EPDM magnetic sealing strips with high thermal conductivity and electrical conductivity, rubber products companies can choose iron oxide magnetic powder to make soft EPDM magnetic strips. There are still many places to pay attention when using EPDM reclaimed rubber to produce magnetic sealing strips, such as the choice of EPDM reclaimed rubber, whether it needs to be blended with EPDM, whether the production process needs improvement, etc. .