Case of Polishing pad for polishing salt crystal

Salt crystal (potassium bromate), this kind of crystal is water-soluble, with a Mohs hardness of 2. The customer is currently using the American PU pad. The customer said that the polishing effect is very good, but the workpiece is deformed, and the customer’s rotation speed is not fast 10RPM, considering the temperature. Too high will cause deformation. Whether the corresponding pad is grooved, the size and width of the groove, and the flow rate of the polishing fluid will all affect the temperature change during the process; secondly, the adhesive backing and brushing glue are also different, and the effect of brushing glue is also different. It is better not to have adhesive backing. Applying glue will affect the flatness. After communicating with the customer, I found that the one currently used by the customer is indeed not grooved. The customer said that he wanted to test our grooved polishing pad. He will continue to follow up in the future. In addition, the price is below 1.27 The thickness cannot be grooved

If the workpiece is deformed after polishing, what may be the influencing factors?

1. Speed

Depending on the characteristics of the workpiece, some cannot rotate too fast. Although the grinding machine speed is not originally too high, for workpieces that are more difficult to process and more sensitive, the difference in rotational speed will also affect the final result.

2. Mat thickness

3. Mat adhesive method

The effect of brushing glue is not as good as that of backing glue. Brushing glue will affect the flatness, causing the workpiece to be deformed.

4. Temperature

Especially for workpieces that are sensitive to temperature, more attention is needed to differentiate possible causes;

a. groove or not

The groove design will be more conducive to the polishing fluid to play its role;

b. slot size and slot width

These will also affect the function of the polishing fluid and correspondingly affect the temperature during the polishing process;

Groove width is generally 1mm, 1.2mm, 2mm

c. Polishing liquid flow rate

Requirement of customer:

After polishing salt crystal with an American PU pad, the polishing results are good, without scratches, but the edges and center of our circular potassium bromide crystal window piece experience greater grinding. The crystal is very soft (2 Mohs) , causing deformation during polishing, even with minimal pressure in grams.

Their goal is to polish a perfectly flat piece. They need flatness around 300 nm or less.