CFF Filter System mainly includes ceramic foam filter. Alumina Ceramic Foam Filters mainly for filtration of aluminum and alloys in foundries and cast houses. To make high quality wheels, it is important that the production is free from any external or internal defects. Casting defects are related to mechanical properties and surface quality. CFF Filter System is also used during low pressure die casting for light alloy aluminium wheel production.
The purity of the metal is important for this reason. The purity of defects caused by melting is called inclusions. Inclusions are based on the chemical composition of the melt. The filter is used to separate inclusions from the melt. The filter will contain inclusions as molten metal flows through the CFF filter system.
Large inclusions are captured by ceramic foam filter filtration mechanism. With the filtration, the formation of filter cake catches the impurities on the surface of the filter. However, the larger inclusions blocking the filter hole will collect smaller inclusions on the filter surface until the filter is completely blocked. Deep filtering is different from other filtering mechanisms. Deep filtration can be interpreted as volumetric filtration. Inclusions cause the filter wall to coalesce and remain separated from the melt.
The type of cermic filter is classified according to its material or manufacturing method. For grinding wheel casting, three types of filters are most commonly used. These are flat filters, foam filters, and extrusion filters. For aluminum castings, the size of the flat screen may be between 1.0 mm and 2.0 mm. The foam filter is classified according to the porosity of the filter (number of pores per inch) (PPI) and porosity change.
If the foam ceramic filter is blocked in front of the cavity, it will result in loss. Therefore, the surface area of the filter, the depth of the filter, the permeability of the filter (mesh size, CSI, PPI) and the geometric characteristics of the filter are critical to the casting quality.
