Cause Analysis on Unstable Quality of Resin Grinding Wheel

There will be many quality problems during the production of resin grinding wheels. Because resin grinding wheel manufacturing belongs to composite materials multidisciplinary comprehensive, its causes are various and complex.

Resin grinding wheel is complex system that is composed of a variety of main and auxiliary materials, whose main materials are abrasives and bond while the auxiliary materials include packing, reinforced materials, coloring agent, etc.

Firstly, some problems should be paid attention on abrasives.

At present, the quality of abrasives is uneven on the market, which is mainly shown in the fllowing aspects:

A. The chemical composition of abrasives tends to be qualified, but the physical properties are poor; And there is still a gap with foreign products in the bulk density of abrasives.

B. The abrasive grain size is of chaos, and there is still large difference with standard provisions.

Secondly, on the binder, we should mainly pay attentions to phenolic resin.

A. The problem about resin quality stability is important, especially the free phenol content of resin. High content of free phenol will accelerate the pyrolysis after heat hardening of resin grinding wheel, which will affect the strength of grinding wheel;

B. The mixing uniformity of resin powder and methenamine: If methenamine, as curing agent of resin, is not enough to be added, it will affect the strength and hardness of grinding wheel; If the content is too high, excessive methenamine will be not combined with resin, and it will increase the number of stomata of grinding wheel, and reduce its strength and hardness.

C. The granularity of binder is too thick or fine: It is generally believed that the granularity of the binder should be fine, which will help to make it uniform distribution. If the granularity is too coarse, the molding materials will not easy to mix evenly, and it will influence the hardness and strength of grinding wheel. Even for coarser granularity resin wafer cutting wheel, the granularity of binder powder should be also finer than 320#.

But if the granularity of phenolic resin powder are too fine, which will bring the mixtures difficulty. It is really difficult to achieve the uniformity of mixtures, which will also influence the cutting and grinding performance of resin grinding wheel.

In addition, there are still some problems about resin grinding wheel manufacturing process, equipments and tooling, test equipments, etc.