Fillers semi-reinforcing

Mica is available in a variety of grades and finds application as a semi-reinforcing filler and more often as a processing dry lubricant owing to its flake-like structure. It is also used as a dusting agent. 

Synonyms Aluminum-magnesium-sodium silicate Uses Semi-reinforcing filler for the mbber industry TlOj extender for paints food-pkg. adhesives, coatings... 

Non- or semi-reinforcing fillers These are usually added to reduce cost. In natural rubber or polychloroprene, they may be used alone, but with non-crystallizing polymers such as butadiene - acrylonitrile or styrene - butadiene copolymers, they can only be used in conjunction with a reinforcing filler. Their effect is to reduce tensile strength and elongation, tear resistance and resistance to set. The effect on modulus varies according to choice of filler, but it is always much weaker than that of a reinforcing filler. 

Table 3. Some non-reinforcing and semi-reinforcing fillers...

Almical semi-reinforcing fillers Alpha Calcit... 

China clay is a widely used white filler in the rubber industry. Depending on particle size, it can be used as a semi-reinforcing filler (hard clay) or a non-reinforcing filler (soft clay) in such applications as chemical liners, bicycle tyres, conveyor belts, shoe soles, gaskets and flooring. Its use in plastics is much more limited. In thermoplastics it is used for speciality antiblocking, in thermosets it is used in urea-, phenol- and melamine formaldehyde, in unsaturated polyesters, and in epoxy resins. 

A semi-reinforcing filler is a particulate material that is able to ... 

Semi-reinforcing fillers -later optimum loading, but with lower strength development... 

Secondary clays are those clays, which have been transported away from their primary source to another location, where they have been deposited as a sediment. The transportation process was usually effective at both mineral separation and at particle size selection, in that only the finer particles remained in suspension long enough to reach the final deposit. Important secondary deposits are foimd in the kaolin belt of south-eastern United States (Alabama, through Georgia into South Carolina) and southwestern England. These clays are very fine with mean particle sizes from 0.1 to 2.0 pm. These are all semi-reinforcing fillers. 

Small particles reinforcing fillers, semi-reinforcing fillers, CaC03... 

Ground natural occurring sihca is a semi-reinforcing filler that may be added in fairly large amounts without increasing viscosity and hardness excessively. Min-U-Sil and Tamsil are available in various particle sizes ranging from 8 to 25 p.m. 

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