The Selection Principle of Abrasive Particle Size in Abrasive Belt Grinding

The selection of abrasive particle size is one of the key factors to determine the machining effect. Generally speaking, the choice of particle size should consider the following aspects.

(1) If the machining allowance of the workpiece is large and the requirement for grinding efficiency is high, coarse particle size should be selected. On the contrary, fine particle size will be better. In general, when machining similar parts, the efficiency of abrasive belt grinding is higher than that of wheel grinding, because all the abrasive particles arranged neatly on the surface of the abrasive belt can play a grinding role and the depth of the abrasive particles embedded on the workpiece surface is larger than that of grinding wheel, when the surface roughness requirement of the workpiece is the same, the abrasive particle size of abrasive belt should be smaller than that of the grinding wheel. For example, if grinding wheel surface grinding machine uses the particle size of 36#~46#, abrasive belt grinding machine should use 46#~60# particle size; if the grinding wheel with the particle size of 60#~80# is used for cylindrical grinding, abrasive belt grinding should adopt the particle size of 80#~100#. Of course, the selection of particle size should be combined with the rigidity of grinding machines and operation skills.

(2) Under the same roughness requirements of the workpiece, fine particle size should be used for the abrasive belt with high linear velocity, and coarse particle size should be used for the abrasive belt with low linear velocity. For example, the sanding-line velocity on the surface of plywood is 15~20ms, and the abrasive particle size is 36#~46#. However, when using a wide belt sanding machine, the linear velocity of the abrasive belt is 32ms, and the abrasive particle size is 60#.

(3) In the process of metallic materials and non-metallic materials, if the surface quality requirements are similar, the metal workpiece shall be processed with fine particle size, while the non-metallic workpiece shall be processed with coarse particle size.

(4) When processing the same type of workpiece, coarse particle size is selected for dry grinding; fine particle size is selected in wet grinding; much finer particle size is selected if lubricating oil is used as the coolant.

(5) Coarse particle size should be selected for abrasive belt grinding with large contact area, and fine particle size should be adopted for abrasive belt grinding with small contact area. Generally, the contact area of plane grinding is greater than that of cylindrical grinding, so in the processing of the workpiece with the same material, the particle size of plane abrasive belt should be slightly coarser than that of cylindrical grinding abrasive belt.

(6) Select the particle size according to the material of the workpiece. When processing the metal with high toughness or soft performance, the abrasive belt is easy to be blocked, so it is advisable to choose coarser abrasive particles. When processing the steel with high hardness, finer abrasive particles are adoptable.