Calcium metasilicate filler

One material that has been used to replace asbestos in certain applications is wollas-tonite or calcium metasilicate. This is also a fibrous mineral filler but with a lower aspect ratio than asbestos. Surface-treated versions are available to improve adhesion to the epoxy matrix. It can be applied at relatively high loading levels to provide for high strength and improvements in moisture resistance.25... 

When glass fibers are compounded in polyamides in high content, warping of the molded product can become a problem. Wollastonite exhibits better properties in this aspect." Wollastonite is a white mineral that consists essentially of calcium metasilicate. It is commonly used as an inorganic filler material of thermoplastic polymers for molding. The wollastonite fibers are treated with silane surface treatments by using y-aminopropyltri-ethoxysilane or y-glycidylpropylmethoxysilane. 

Aluminum silicate Aminotrimethylene phosphonic acid Barium hydroxide lime Calcium metasilicate Calcium sulfate Calcium sulfate dihydrate Cellulose Diatomaceous earth Diatomaceous earth, amorphous Magnesium carbonate Sodium polyacrylate Talc filler, paper coatings Aluminum silicate dihydrate Bentonite Calcium metasilicate Whiting Wollastonite filler, paper sizing Kaolin... 

Calcium metasilicate causes an increase in flexural stress value while the impact strength is retained at its original high level. The elastomeric properties are retained if the mass percent of filler does not exceed 30%, as a result of the significantly lower L/D ratio of calcium metasilicate compared with that of glass and cotton fibre. Spherical fillers make it possible to retain the elastomeric properties and to increase the strength by almost 100%. A marked reduction in compound cost can also be gained, since most of the fillers are some 5-10 times less expensive than CPEE. 

Fillers can be crystalline or amorphous. Examples of crystalline fillers include calcium carbonate and anatase (titanium dioxide) whereas solid glass beads are amorphous. Many, but not all, fillers are extracted from the earth s crust by mining or quarrying operations examples include calcium carbonate, talc, bentonite, wollastonite (calcium metasilicate) and titanium dioxide. Some fillers are extracted along with impurities that can seriously affect the colour, electrical properties and toxicity of plastics unless they are removed. Others, such as wood flour, have organic origins. The use of wood flour itself has been rather limited because of compatibility problems. 

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