Wollastonite Calcium Metasilicate

Wollanite. A material claimed to increase the hardness and strength of earthenware, and to comprise crystals of wollastonite and cristoballite sintered together. (Oreste Bitossi, Livorno, Italy.) Wollastonite. Calcium metasilicate, CaSi03 m.p. 1544 C There are two principal forms the natural, p, form sp. gr. 2.92 thermal expansion (0-1000°C), 11 X 10- the synthetic, a, form which is also known as pseudo-wollastonite sp. gr. 2.91 thermal expansion (0-1000°C), 6 x 10-. The a form is slowly produced when the P form is heated above 1200°C. There are economic deposits in New York State, Finland and USSR. Wollastonite has been used in some... 

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. 

ATH used in flame-retardant compounds precipitated silicates micas, wollastonite or calcium metasilicate barium sulphate, used for its opacity to X-rays and high density litho-pone quartz used in flour form. 

Wollastonite is a natural calcium metasilicate mineral with an acicular structure. Silanized and uncoated versions with maximum fiber lengths up to 25 pm are used as inexpensive secondary reinforcements in friction materials. Short fiber attapulgite clays have also been developed as secondary reinforcements. 

SYNONYMS calcium hydrosilicate, calcium metasilicate, calcium monosilicate, calcium polysilicate, calcium salt of silicic acid, wollastonite (mineral). 

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 silicate, natural n. CaSiOs. It has white color and acicular particles. It is characterized by high flatting action, combined with low oil absorption, and is used as an extender in paints, ceramics and plastics. Density, 2.9g/cm (24.2lb/gal) O.A., 25—30 particle size, 7 pm (fine particle grade) hardness (moh), 4.5. Syn wollastonite and calcium metasilicate. 

Wollastonite is a naturally occurring calcium metasilicate. It is the only commercially available pure white mineral that is wholly acicular typical length to diameter ratios range from 3 1 to 20 1. The world s largest known and purest deposit is owned and operated by Nyco. 

Calcium metasilicate or Wollastonite (Nyad 400) offers more reinforcement with high hot tear resistance, necessary when the part is undercut, for example, in a shaft seal. It is often used in conjunction with barium sulfate. 

The textile roller(Fig. 1) in the textile maehines is a worn part which should be replaced after a eertain time. The material of the roller is PBT. PBT has good dimensional stability, mechanical strength, stiffness, and fire retardant characteristics. To improve the meehanical strength, most of the plastics are filled with glass fiber. In this study, both glass and Wollastonite fiber filled PBT are investigated. Wollastonite is a calcium metasilicate (CaSiOs) which can improve thermal and dimensional stability at elevated temperatures[8]. 

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