Manual Grinding & Polishing
Manual grinding and polishing is a highly specialised craft as well as a traditional one
Manual grinding and polishing is a highly specialised craft as well as a traditional one. Van Geenen BV has built up expertise and know-how for over 40 years, enabling it to achieve any surface finish with its grinding or polishing techniques. We are continually optimising our process so that we can guarantee the highest quality. Products of every possible shape and made from a diverse range of materials, just a few items or an entire series, are finished in a professional way based on your specifications. Also, we are always happy to answer your questions and to provide the advice you need.
Whether you are dealing with stainless steel, aluminium, brass or different non-ferrous materials, we are the right address for every possible finish of the highest quality. Needless to say, all products are delivered clean and in the correct packaging.
We offer a range of surface finishing services:
- Grinding and polishing to Roughness value (Ra-value)
- Grinding to grit size
- Grinding of welding seams and processing traces
- High-gloss polishing up to Mirror 8
Fig. 1 Grinding and polishing the sink.
Grinding based on roughness value
Grinding based on Roughness value (Ra value) is a precision job that Van Geenen carries out to a very high standard. Grinding to a Ra value is of the highest importance for products in many different sectors such as the food industry, pharmaceutical industry and the production of machinery. Examples include the inside of a tank for the pharmaceutical industry or screw conveyors in the food industry.
Hygiene standards in these industries are exceptionally stringent, and it is essential that surfaces have a low roughness value to avoid product adhesion (that would cause bacteria to develop) and that the material is easy to clean. Our experts are able to achieve any desired surface roughness irrespective of dimensions, shape, thickness and type of material.
To achieve the right roughness, it is essential to determine the right treatment for each particular material. Each product is required to undergo its own individual assessment, which helps us to determine how to achieve the optimum result. In this, an important role is played by the type of product, material, quality and the desired surface finish.
We will of course send you a report with measures of the surface roughness. Our measuring equipment is calibrated several times per year, which means that the values measured are always correct.
Fig. 2 Grinding on roughness value.
Grinding to any grit size or RA value
Polished products are used in many industries. Works of art or architectural objects are often polished. The exterior finish of a control sheet is another example of the type of product that Van Geenen grinds and polishes to a particular grit value almost every day. Grinding to a particular grit size enhances the visual look of the product.
Van Geenen will grind your product to a range of different grit sizes.
Grinding to grit size 320 is quite popular. Using this specification, the end product has a slick and contemporary look with beautifully visible polishing lines. As part of the grinding process, it is of the utmost importance to treat the material in the right way. This is where the characteristics of the material come into play. The thicker the sheet metal, the more steps are required to achieve the end result. Thanks to our many years’ experience, we know exactly how to treat each type of material to achieve an optimum result.
Fig. 3 Grinding to grit size or RA value.
Directional or directionless brushing
Another surface treatment to achieve a beautiful-looking result is brushing, also known as Scotch-Brite. Our know-how and experience ensure that we finish your product to the highest standards, resulting in a lovely matte-look finishing touch. As part of this process, you could also opt for directionless surface brushing. This gives the surface a matted look without any visible trails of brushing that go into one direction.
The effect of brushing is that a polished structure acquires a matted look which makes it “softer” on the eye. Scratches made by grinding become less noticeable and harder to spot. Surface brushing also reduces the visibility of future scratches. Another option is high-gloss surface brushing to achieve a uniform, modern look. The surface takes on a sheen and starts to act as a mirror, but the brush strokes are still clearly visible.
Fig. 4 Metal brushing direction or directionless.
Welding seams and processing traces
Once we have assembled the different parts of your order, you could choose to eliminate welding seams entirely by smooth grinding. This will result in a uniform look without visible welding seams. Does your product need to have a visual appeal or does it have to be upgraded to a Ra value? Van Geenen are the experts with the right know-how to guide you to the very best result that meets your objectives.
Assembling the different parts of your order could leave processing traces. We know exactly what to do to grind or brush away any traces of the processing process to achieve a slick, contemporary look with the exact finish you are looking for.
Fig. 5 Welding seams and processing traces.
A specialist trade requiring a high level of experience is high-gloss polishing of stainless steel products. Van Geenen is well known for its expertise in this area.
Polishing gives a mirror finish to a surface and creates a high degree of shine. High-gloss polished materials are used by builders of superyachts, for example, and have also found their way into art and interior design. This type of finish exudes luxury but in addition, thanks to its extremely low roughness value of 0.02 µm (microns), it is also in high demand in the pharma industry for, example.
Fig. 6 High-gloss polishing of art.