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发布日期:2021年12月02日
Three production processes of resin grinding wheels

The advantages of ceramic grinding wheels are their natural porosity and good chemical stability, so they are suitable for dry and wet grinding, but ceramic wheels have poor elasticity and require a high sintering temperature, which limits their development. Resin wheels have the advantages of good elasticity and low sensitivity to shock, impact and side pressure.

It can adapt to higher speeds and improve the grinding performance, so it is particularly suitable for grinding wheels and cutting wheels. Its good elasticity makes it suitable for ultra-precision grinding and surface polishing. The production processes of resin grinding wheels mainly include cold pressing process, semi-hot pressing process and hot pressing process.

1. Semi-hot pressing process:

The pressing temperature of the semi-hot pressing process is usually 50-65°C, and the remaining processes are completely consistent with the cold pressing process.

At this pressing temperature, the viscosity of the liquid resin becomes smaller, and the powdery resin can be well integrated, so that the fluidity of the entire resin system is improved, and it is easier to fully penetrate each space, even if the pressure of the press is not too high. , It can also be well formed, and the pressure holding time does not need to be too long. It is especially suitable for continuous operation of automatic pressing production lines.

2. Hot pressing process:

The hot pressing process is usually used to process larger-density grinding wheels. The density of ordinary grinding wheels is usually 2.4-2.7g/cm3, the highest is 2.9g/cm3, and the density of high-density grinding wheels can reach 3.1-3.5g/cm3. High density, hot pressing process is the most suitable.

The mixing requirements of the hot pressing process are different from the cold pressing process. The dry mixing method is usually used, or furfural less than 1% of the weight of the abrasive is used as a wetting agent to wet the abrasive, and then mixed with the powdered resin evenly. Powdered resins are usually selected with low fluidity. The suitable range is 15-20mm or even smaller. Liquid resins and powdered resins with large fluidity cannot be used because they are liable to overflow during hot pressing.

3. Cold pressing process:

The binders used in the cold pressing process include wetting agents and powdered resins. Liquid phenolic resins, furfural, furfuryl alcohol, and cresol are commonly used as wetting agents. Liquid phenolic resins are the most used. First, install the mold, weigh the required amount of abrasive into the mold cavity, scrape it flat and press it. Need to place the reinforced glass fiber mesh as required.

Then pressurize it at room temperature, usually the pressure range of cold pressing is 15-30N/mm2, preferably 15-25N/mm2. The choice of pressure depends on the plasticity of the material and the density required by the grinding wheel. It is not appropriate to use excessively high pressure, otherwise the abrasive will be crushed. The pressing time is usually 5-50 seconds, preferably 5-30 seconds, the length of time depends on the density and shape of the grinding wheel and the plasticity of the material.