A brief discussion on the control method of glass grinding chipping

The most common problem encountered when grinding glass is that the amount of chipping is out of range, so why does chipping occur?Then we have to start with the internal structure of the glass.Modern glass theories include crystal theory, irregular network theory, polymer theory, pentagonal symmetry theory, gel theory, etc., but the more popular ones are crystal theory and irregular network theory.

The crystal theory focuses on explaining the micro-unevenness and order of the glass structure.

The theory of irregular networks reflects the characteristics of “short-range orderly and long-range disordered” in the internal structure of glass.

The two hypotheses contradict each other but can each explain the law of change in the properties of glass, and after years of experimental demonstration by scientists, the views of the two theories are gradually converging. Now the unified view is that glass is an amorphous substance with the characteristics of short-range orderly and long-range disordered structure.

At this point, the answer to why glass produces chipping is about to come out. It is because glass has an amorphous and irregular amorphous structure, which means that chipping is inevitable when grinding glass, and it is random.However, unavoidable problems do not mean that they cannot be improved or optimized. The input in the grinding system determines the output effect. The four major input factors are equipment, tools, parameters and workpieces. The generation of chipping is the result of the comprehensive action of these factors. Here we focus on improving the method of controlling chipping from the tool aspect.

The characteristics that affect the grinding effect of the grinding head are: diameter, particle size, groove angle, and runout (concentricity).

diameter

The smaller the diameter of the grinding head, the lower the grinding linear speed, resulting in an increase in the grinding amount of a single abrasive on the sand surface, which makes the grinding force greater and prone to chipping.Therefore, the diameter of the grinding head should not be too small, and the diameter and size of the grinding head should be reasonably designed.

Particle size

The thicker the particle size, the smaller the number of abrasive particles on the surface, which also leads to an increase in the grinding amount of a single abrasive during grinding, so that the grinding force becomes greater, and the more likely it is to produce chipping.In order to effectively control the chipping within the required range, the particle size of the sand number should be reasonably selected.Among them, the choice of refined particle size is particularly important. If the sand number selected to be used fails to meet the chipping requirements of the product, it is difficult to process a qualified product.Therefore, it should be strictly required to choose the appropriate abrasive particle size according to the needs of the product.

Slot angle

The angle between the finishing grooves will affect the amount of chipping to a certain extent, because the grinding head will produce compressive stress and shear stress when grinding the glass, and the shear stress has a greater effect on the chipping. Reducing the angle between the grooves can bias the force to the compressive stress, thereby reducing the chipping.However, it should be noted that the reduction of the groove angle will affect chip removal to a certain extent, so it is very important to control the appropriate angle.

Concentricity

Concentricity is what we often call the size of the beating. The larger the beating, the more unstable the grinding head will be, and the number of abrasives involved in grinding will decrease, resulting in a large amount of grinding of a single abrasive and a large force. , Resulting in chipping. The easier it is to produce.Therefore, strict control of the concentricity of the grinding head is also a top priority.