(1) the stability of resin quality, especially the content of phenol in resin. Excessive free phenol content will accelerate the resin cracking of resin grinding wheel after heating and hardening, and affect the strength of the fast cheap metal grinding disc.
(2) The mixing uniformity of resin powder and urotropine, as the hardening agent of resin, the addition of urotropine is insufficient, and the hardening of resin is incomplete, which affects the strength and hardness of grinding wheel; if the content is too high, the excessive Urotropine does not combine with resin, and decomposes and volatilizes in the hardening process, so that the porosity of high quality metal grinding disc increases and its porosity decreases. Strength and hardness.
(3) the binder grain is coarse or oversized.
It is generally believed that the size of the binder is fine, which is conducive to the uniform distribution of the binder. When the grain is rough, the forming material is not easy to mix evenly, which affects the hardness and strength of 180*6*22mm metal grinding disc. Even for the resin slice cutting grinding wheel and cymbal grinding wheel with coarse particle size, the selected binder (resin powder) should be finer than 320 #.
But if the particle size of phenolic resin powder is too fine, it brings difficulties to the mixture, and it is difficult to achieve uniformity of the mixture, thus affecting the grinding performance of resin grinding disc.
The price of a grinding wheel made with a good binder must not be too low. So it’s hard to find a high quality metal grinding disc with a China cheap grinding disc price.