Abrasives such as abrasive belts, fibre discs, flap discs, abrasive sleeves and polishing tools are available in a wide variety of designs, sizes and formats. They are not only used for sharpening, but also for smoothing and polishing objects and for dimensional stability. Textile-based industrial abrasives are one of the key segments of abrasives.
For decades, aqueous polymer dispersions have increasingly been used to manufacture such products – to improve mechanical and thermal resistance as well as adhesion between layers as muchas extending the service life of the material.
Aqueous latex dispersions give industrial abrasives on textile substrates important properties such as flexibility, heat resistance and durability during the actual grinding process. Typically, the abrasive consists of an impregnated fabric made of cotton, polyester or a blend as carrier. The backing is lacquered on the back and the abrasive particles sit on the backing, fixed with phenolic resin.
The use of aqueous polymer dispersions to impregnate and coat the backing allows modifications to the stiffness of the fabric. It improves the mechanical properties and adhesion between the abrasive particle layer and the backing. It also improves heat resistance and durability to coolants. And it also acts as a barrier to prevent the phenolic resin from damaging the backing through the top layer, write Michael Karnop and Sören Butz of Synthomer Deutschland GmbH in the trade journal Melliand International.
Optimisation And Quality
Newer products have better peel strength and higher thermal resistance and are clearly more environmentally friendly. The parameters of the polymerization process are optimized to ensure a clean, low VOC product with low CO2 emissions.
One of the key functions of such a polymer dispersion in textile-based abrasives is to improve the mechanical bond between the abrasive particles and the backing, regardless of the fibre type. This contributes directly to the durability and life of the abrasive.
Grinding and polishing is usually carried out at a very high speed. Thermal resistance is therefore a decisive property that must be taken into account when developing a high-performance dispersion for industrial abrasives. The composition of this polymer dispersion, in particular the monomers and crosslinker components, has a significant influence on the thermal resistance.
New products also have good compatibility with phenolic resin, which is often used to grind the sand fixation on the surface. By mixing a small amount of these products with the resin, a change in flexibility is achieved so that the final product can withstand the bending process towards the end of production. This involves stretching and bending abrasives at different angles to better match the abrasives and substrates.
By optimizing process parameters and modern quality control, current products can be developed that contain ten percent more solids with a constant particle size distribution than their predecessors.