Grinding

Deep-going imperfection can be removed by Grinding. Smaller imperfections, where only a little of the material must be removed in order to obtain the required surface, it could be an advantage to grind. Especially if it is desired to have the surface polished at the end, grinding is often necessary.

Grinding with sanding belt or belt sander is suitable, whereas circular grinding is not too good. With the sanding belt you obtain a better cooling of the grinding surface. The belt speed should be in the area of 20-30 m/s. The pressure against the belt must be very small. Grain size on the sanding belt 400-500.

Free-hand grinding must be done with a small pressure, otherwise the grinding paper will settle quickly.

When using various grain sizes on the grinding paper you can obtain the desired surface roughness.

Polishing

Several plastic materials can be polished to get a certain glaze - from satin (silk mat) to full gloss. The result depends on the pretreatment of the surface as well as the precision and competences of the operator. The surface must be treated with abrasive paper of various fineness numbers if it has been machined. Then polishing compound of one or two fineness numbers can be applied and processed with a polishing wheel. The surface speed can be 25 - 30 m/s. The wheel must be moved in circular movements to avoid local overheating. Vink has its own polishing compound without harmful materials and therefore it is suitable for all plastic types. Usually, ordinary polishing agents for treatment of car enamels can be used though.

You can also polish mechanically in which case you should use a diamond tool. When doing the roughworking use an industrial diamond and when doing the finishing use a natural diamond. The result will be very fine.