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    February 13
  • zengbin xu 1) Raw material issues The cutting piece is a complex system composed of a variety of main and auxiliary raw materials, the main materials are abrasives and bonding agents, and the auxiliary materials include fillers, reinforcing materials and the like. a. Abrasive problem Abrasive is the main material for grinding in the <a href="">low price disc for metal</a>. At present, the quality of the abrasive material on the market is mixed, and the main performance is as follows: 1) The chemical composition of the abrasive is often qualified, but the physical properties are poor, such as hardness, strength, self-sharpness, crush resistance, thermal stability, hydrophilicity, etc.; 2) The particle size composition of the abrasive is chaotic, which is quite different from the standard. b. Bonding problems In the dicing sheet, the abrasive particles are bonded together by the bonding agent, and the performance of the bonding agent directly affects the performance and quality of the dicing sheet. 1) The quality of the resin is unstable, and the free phenol content in the resin is high or low. The so-called free phenol is phenol remaining in the resin, the molecular formula is C6H5OH, long-term heating can crack the hardened resin, affecting the strength of the cutting piece; 2) The resin powder and urotropine are not evenly mixed. The scientific name of urotropine is hexamethylenetetramine ((CH2) 6N4). As a hardener for the resin, the amount of urotropine is insufficient, and the resin is hardened. Completely, affecting the strength and hardness of the cutting piece; if the content is too high, the excess urotropine is not combined with the resin, and is decomposed and volatilized during the hardening process, so that the pores of the cutting piece are increased, and the strength and hardness are lowered. The resin powder and urotropine are mixed unevenly, and the consequence is that the urodose content is too high or too low; 3) The particle size of the binder is too coarse. It is generally considered that the particle size of the binder is fine, which is advantageous for uniform distribution of the binder and favorable contact of the hardener. If the particle size is too coarse, the molding material is not easily mixed uniformly, which affects the hardness and strength of the cutting piece. Even for the coarse-grained resin sheet cutting dicing sheet and the enamel-shaped cutting sheet, the size of the binder (resin powder) selected should be finer than 320#. A fine-grained dicing sheet product is produced with a particle size requirement of a few microns. 4) Manufacturing process problems One of the characteristics of the manufacture of the dicing sheet is that the process is very strong, and any omissions and deviations in the manufacturing process may have a negative impact on the quality of the dicing sheet. During the slewing test, it was observed in the ruptured cutting piece that some of the fractures were coarse, loose, and missing. The mesh cloth was slightly pulled and detached. The occurrence of these defects was related to the improper manufacturing process. There are many problems in the process of compounding, molding, firing or curing, and shaping processing. a. Compounding process The ingredients are the preliminary preparation of the mixing. The mixing material is an abrasive, a wetting agent, a bonding agent, a filler, etc., in a certain procedure and manner, so that the wetting agent, the bonding agent and the filler are uniformly adhered to the abrasive grains to be evenly distributed with each other. The key to the mixing is uniformity, and the molding material should be: the components are evenly distributed, keep loose, easy to spread, and have good molding properties. In some production plants, the mechanical mixing or manual mixing time is not enough, and the mixing and sieving operations are relatively sloppy, which does not meet the above requirements. b. The correct operation of the forming process is to pour the molding material in the middle of the mold, and then use a special scraper to spread the material in a radial direction so that it is evenly distributed in the mold, so that the blank body reaches the specified size and shape, Cracks or layers are created. Some employees of the company have no way to operate, resulting in uneven quality distribution, shape tolerance and static balance. c. Firing or curing This is the most critical production process. There are two factors that easily cause quality problems. One is that the temperature difference between the curing oven or the firing kiln is too large; the other is that the method of loading the furnace is improper. The temperature difference in the oven or kiln is generally measured when the cutting piece is not installed. At this time, the temperature difference is small. When the oven or the kiln is filled with the cutting piece, improper filling will hinder the flow of hot air in the oven or the kiln, and the temperature difference will increase. Deviation from the set hardening specification makes the curing (hardening) quality of the dicing sheet insufficiently guaranteed. d. Shaping Some cutting pieces are shaped after firing or curing to ensure the geometrical dimensions and geometrical tolerances of the <a href="">5 inch resin cutting disc for metal</a>. Some enterprises have missed the process, and some have been shaped and processed, and the process is not in place. e. Process documents and process parameters are hard to be set. Some small enterprise process documents are incomplete. The process parameters will not be adjusted according to the fluctuation of raw material composition, the change of climatic and environmental conditions or the different requirements of users. The quality of the cutting pieces produced by these enterprises is often unstable.
    October 31, 2018