Thickening additive Subject

The water content of the thickened nitrocellulose pulp is reduced to 30-40% in centrifuges of the type similar as those used in the manufacture of sugar. In many plants, additional dehydration is carried out in hydraulic presses, in which the nitrocellulose is subjected to a pressure of about 20 kg/cm2 and formed into blocks or cakes in which the water content is 20-30%. Clearly this is advantageous from the point of view of transport. 

The properties of unsaturated polyesters are also modified by a host of additives, such as thixotropic agents, chemical thickeners, fillers or extenders, fire-retardant chemicals, glass-fiber, and other reinforcement. A discussion of these areas is beyond the scope of this book. Most of this technology is disclosed in the extensive polyester patent literature. However, many books and review articles on polyester, " as well as manufacturers product literature, give good coverage of the subject. 

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