1. Causes of broken beads
The popular zirconium silicate bead and pure zirconium bead on the market, in terms of production technology, basically for the electric fusion method and sintering method two.Beads are formed in hot air, cold air or electrolyte. If a certain key technical parameters are not well controlled, the following fragile beads will be produced: bubble beads, snowman beads, tail beads, flat (oval) beads
2. Judgment of normal wear and breakage of beads
The grinding beads that work for a period of time become smaller, and the surface is smooth without edges and corners, which should be the wear of normal beads;Such as the appearance of the beads with edges and corners, sheet shaped beads this should be produced by the broken beads.
3. Causes of broken beads
On the one hand is the quality of the beads, on the other hand or the strength of the beads of this material can not be better than a certain type of sanding machine.The grinding bead in the normal operation of the sander, will be subjected to about 1 kg of pressure, relative to the glass bead can withstand about 5000 kg of force and zirconium silicate bead 9000 kg, the grinding bead in the sander force is negligible, so the reason for the broken bead should be focused on the equipment and process, and take the corresponding solutions.
4. The solution of broken beads
1). Dispersion plate: Dispersion plate is installed in reverse, loose or cracked.
2). Separation device: the dynamic screen ring is notched and the screen mesh is damaged.
3). Feeding pump: after the gear pump is suddenly turned off, the pressure in the sander will reverse press the beads into the pump.This can be avoided by installing a check valve while maintaining regular cleaning of the feed pump.
4). Inner cylinder: there are defects in the inner cylinder.
B. Production operation:
1). Mixed use of small and small beads: this situation shows signs of improving grinding efficiency at the beginning, but with the lengthening of grinding time, the situation of grinding small beads by large beads is produced, and then the deformation of small beads is accelerated and even broken.The solution is to try to use beads of a uniform size.
2). Mixed use of different brands of beads: because of the hardness and density of various beads are not consistent, it is easy to produce hard beads to eat soft beads, so this form should be put an end to.
3). The viscosity of the paste is too thin or too thick: relative to the grinding beads of a certain density, it is so easy to cause the accumulation of beads and direct contact with the abrasive parts of the sander and accelerate the wear and crushing of the beads.
4). The material flow is too fast: this will cause the beads to backlog at the material outlet, and accelerate the wear of the beads and the sander accessories here.The solution is to use the intermittent boot method to loosen the backlog grinding beads, and redistribute evenly, and then adjust the flow of materials.
5. How to solve the crushing of grinding beads
If the beads are rounded rather than angular like broken glass, they are naturally worn beads.The beads may be ground into various shapes such as disks, ovals, or smaller spheres.This condition is called abrasion, but the degree of wear varies.
From the point of view of force, if the liquid viscosity is very low, such as when cleaning the sander with solvent or water, the thrust of the material is not strong enough, and the beads may contact the dispersing plate and break.This is one of the important reasons why we recommend keeping cleaning time as short as possible.If the machine is cleaned with a low viscosity liquid, the beads will also wear away other beads or contact parts of the sander.In order to obtain a long service life of grinding bead and sanding machine, it is recommended to use resin for cleaning and maintain sufficient material viscosity in the production process.Many people encountered the old beads into the new bead after the test bead broken.This problem will be analyzed and the solutions discussed below.
1). The internal contact parts of the sander are not installed correctly: the dispersing plate is loose or the edge of the dispersing plate is sharp, there is a foreign body in the sander, the internal valve is loose, etc., all of which may cause the grinding beads to be broken.
2). Sand mill contacts are worn or not properly installed: the dynamic separator or screen may be worn, the screen may be broken or reversed. If the grinding media passes through the separator and enters the feed pump, the pump will crush the beads before it is blocked or shut down.
3). Back Pressure: When the feed pump is turned off, the residual pressure in the sander pushes the beads into the pump, so that when the pump is turned on again, it crushes the beads.Check valves are not necessarily reliable and sometimes allow beads to pass before the valve is closed.
4). Overstock of grinding beads: this will happen if the grinding beads are piled up at the bottom of the sander or the speed of the working pump is too fast, which causes the grinding beads to be concentrated at the outlet of the horizontal sander.The solution is to start the sanding machine to open – close – open – close point way to loosen the backlog of grinding beads.
5). Dispersion plate wear: This situation may be difficult to determine.The edge of the worn disc is very bumpy, and the edge of the disc is where the linear velocity of the disc is high and strong eddies may be formed.
In addition, for the vertical grinding machine, grinding beads due to gravity concentrated to the lower edge of the dispersion disk.All these factors combined, it is possible to cause grinding beads to break.The wear of the dispersing disc is largely caused by the slow speed of the feeding pump and the high density of the grinding bead.This problem can be solved by replacing heavily worn parts and reloading the same batch of grinding beads.
6). Mix the grinding beads produced by different manufacturers.Products from different manufacturers may differ in density.This increases the friction between the beads.The solution is never to mix different manufacturers of grinding beads.If they are suspected of being mixed, throw them out altogether.
7). Accidentally adding used old beads to the sander.
8). Garbage or some small worn beads: Often there will be garbage or some small worn beads attached to the screen, shaft, bracket, or some other inner corner of the machine.When new beads are added, they may come loose from the attachment site and blend into the additional beads.This gives the illusion that the new beads will immediately break, when all you are actually seeing is the natural wear of the old beads.If the problem is not too big, you can let the small things go naturally after a certain period of time.Otherwise, you must completely discard the old beads and replace them with new ones.
9). The cleaning beads can be cleaned with water, solution or resin according to the formula;Cleaning should be kept at low speed, should press the “start – off” button of the grinding machine for intermittent cleaning.
6, adding the principle of grinding medium
If the grinding efficiency of the grinding machine is found to be reduced, it is a possible signal to add beads.Users can master the actual loss rate of beads according to their own process conditions, and make regular sieve and add beads.The overly fine beads are sifted out through a sieve about two-thirds the diameter of the beads.(For example, if you use a bead screen of 1.2 ~ 1.4 mm, it should be 0.8 mm), then add the difference beads.
7. How to add grinding medium
Due to the natural loss of beads, beads particle size will be smaller and smaller, in order to maintain a uniform filling amount and avoid fine beads clogging or entering the separation device, should be based on the life of the grinding medium and the user’s own process conditions to screen the beads and add a certain amount of grinding medium.It is recommended to screen beads after 100-200 working hours and add appropriate amounts of new beads.
Send your message to us:
Post time: Mar-05-2021