Development of consolidated abrasive grinding
Due to the low efficiency of abrasive grinding, the research of fixed abrasive has been produced.
The fixed abrasive grinding is a method that the scattered abrasive is consolidated with adhesive and made into a special abrasive tool for grinding on the grinder. Fixed abrasive grinding can greatly improve the grinding efficiency, so many experts at home and abroad attach great importance to the fixed abrasive grinding method, and have carried out a lot of research.
At present, there are still some problems in the dressing of fixed abrasive tools. In order to prevent abrasive wear and abrasive waste, the working time and labor intensity of workers are increased, and the production cost is increased. Therefore, it is necessary to further improve and perfect the fixed abrasive grinding method.
On the preparation of consolidated abrasiveAt present, foreign countries, such as the United States and Japan, have developed a new type of consolidated abrasive lapping plate, which constitutes a precision lapping system for lapping thin films, making the polishing effect of processed products more precise and consistent.There are four main elements in the structure of the abrasive film:
1 base material:
Polyester film 857 (PET), with large longitudinal and transverse tensile strength, small expansion, strong and tough, and uniform thicknessEven and stable. The thickness standard of base material is: 25, 50, 75 μ M. With the requirement of automation, the preparation and grinding performance of resin diamond grinding disk for glass processing of display screen are required 14Thin film, the thick film is not qualified, so there are 7, 10, 12, 23, 27, 30, 37 μ M series.
2 abrasive:
Japan mainly uses Al 2O 3, SiC and other abrasives, as well as Cr 2O 3(grinding head), CeO2, monocrystal and polycrystal synthetic diamond, FeO, etc. It needs to have fine particle size and even particle size distribution, which requires strict control of abrasive particle size distribution, without large particles. 3M, USAThere are four kinds of abrasive particles produced by precision grinding: Al2O3, SiC, artificial box corundum and CBN. All abrasive particles are finely screened and used It can be used for dry or wet grinding.
3 binder:
Mainly polymer resin and dozens of compound additives. Ethyl amino formate. The first two are relatively hard after curing, and the latter is relatively soft. Generally, it is required to apply the film twice, the first time is to increase the adhesion of the film.
4 coating:
Electrostatic method and roll coating method are mainly used. Binder in electrostatic method. The base material is polyester film. The abrasive material is A12O3 、SiC。 Roll coating method is mainly by means of printing technology, abrasive and binder mixed roll coating, coating thickness is controlled by roller, that is to adjust the gap between rollers. In addition, there are mixing method, sintering method, electroplating method and Ni plating method Law, etc. In Japan, the upper limit of heat-resistant temperature of grinding film is the temperature of polymer bonding material, about 250 ℃. commonly Wet grinding is adopted, and the coolant is water and oil. Generally, water can meet the requirements (such as tap water). Pure water is used for precision machining, and lamp oil is used for grinding aluminum alloy.
Precision grinding using abrasive film is more advanced than abrasive belt tools. It can improve the production capacity and efficiency, high qualified rate, good quality, broaden the production range, and accurately control the whole grinding process.