Screen silicon carbide and other abrasives in different fractions with just one machine

RHEWUM is able to screen up to 12 mono-fractions of abrasives in only one single machine

Screening of abrasives is carried out to produce as much mono-fractions as possible from the feed. According standard for abrasives in Europe is FEPA (Federation of European Producers of Abrasives). Further standards are CAMI (Coated Abrasives Manufacturers Institute) and ANSI (American National Standard Institute). These various standards are not complete comparable to each other. Due to the European standard FEPA the granulometry is defined in a range of particle size. The American standard ANSI resp. CAMI is based on the average particle size.

Abrasives are consisting of resistant material particles which are used in bounded manner for specified abrasion of various materials. The resistant material particles are bound on a basis e.g. sandpaper, sanding disks, cutting wheels or brushes. The angle of cutting of the resistant material particles in the abrasive tools is diffuse. Abrasive tools resp. abrasives are differentiated in natural and synthetic materials. Natural materials are quartz, aluminium oxide (corundum), emery, garnet and natural diamonds. Synthetic materials are silicon carbide, chrome oxide, cubical boron nitride and also diamond and aluminium oxide.

• Aluminium oxide is the most common used abrasive and RHEWUM already delivered the respective large number of screening machines for this material. Most important characteristics of aluminium oxide are its hardness and durability. A well known product is special fused aluminium oxide with over 99.9% Al2O3. Special fused aluminium oxide is suitable for steel with more than 60HRC and glass. Ruby aluminium oxide contains additional dissolvable metal oxides, first of all Cr2O3. Brown aluminium oxide contains more than 94 % Al2O3. Semi-friable aluminium oxide is a mixture of brown aluminium oxide and white special fused aluminium oxide. Zirconium aluminium oxide contains 10 to 40% of zirconium oxide and is mixed up with brown aluminium oxide and then used for sanding disks.
• Silicon carbide is characterized by its firm and sharp-edged crystals. One single abrasive grain normally only consists of one or a few crystals. It is more firm and brittle than aluminium oxide. Areas of application are non-ferrous metals, stainless steels, ceramic and mineral materials as well as high-carbon steels. Furthermore there is high-grade green silicon carbide for the treatment of glass, porcelain, marble, gemstones, cast stone, light alloys and non-ferrous metals as well as leather.
• Boron nitride is only suitable as abrasive in cubic shape. Therefore it has to produced by high-pressure sinthesis from hexagonal crystalline boron nitride. Sinter bronzide, synthetic resin and ceramics are used as binder. From 730°C onwards the hardness of boron nitride is higher than of diamond. So boron nitride is suitable for the cutting of diamonds.
• Diamond is the material with the highest hardness in nature. Natural diamonds are in the majority of cases a little bit harder than synthetic ones, both are used as abrasives. Depending on area of application diamond abrasives bound withnickel, copper, synthetic resin or other special alloys as well as bounded galavnic on a steel base body. They are used for precise cutting of hard metal, cast iron, cutting ceramics, silicium, rubber, non-ferrous metals, iron carbide alloys, nickel and chrome alloys.

RHEWUM is able to screen up to 12 mono-fractions of abrasives in only one single machine!

Separation of blasting abrasives with the highly developed RHEWUM-technology

In the supply of screening machines for abrasives the highly wearing products are the main challenging point. A sufficient wear protection has to be provided in any case. Screening machines designed as long stroke type or tumbling screens as well as screens with linear motion are not recommendable. Considerable wear at the screen itself and the sensitive screen cloth caused by the translatory motion of these types of machines is unavoidable.