Curing of tires

Mechanical loss also varies with the cord construction variables such as denier per yarn strand, number of strands and number of twists per unit length ( 2 ). Significant changes In mechanical loss are also observed during the post treatments of grelge tire cords. These Include the steps of cord ten-slllzatlon, application of the adhesives and curing of tires. 

Methylol-terminated para-alkyl-substituted phenol formaldehyde resin is used as the vulcanizing agent for compounds based on butyl and EPDM rubber. The alkyl group is usually octyl. It is commonly used to cure butyl rubber where superior heat resistance is needed. Therefore, this vulcanizing agent is commonly used as the curative to make butyl bladders for repetitive curing of tires. It is also sometimes used in dynamic vulcanization with a tin chloride activator to make thermoplastic vulcanizates (TPVs). 

The production of tires and inner tubes involves three general steps mixing and preliminary forming of the raw materials, formation of individual parts of the product, and constructing and curing the final product. In total, 73 plants use these general steps to produce tires in the United States. 

The irradiated components can be placed adjacent to sulfur-containing unvulcanized elastomeric compounds and, when necessary, coated with suitable adhesive between the contacting surfaces to ensure good bond after final cure of the tire. ... 

Durallnk HTS. [Monsanto] Disodium hexamethylene bisthiosulfate post-vulcanization stabilizer for sulfur cures of NR, IR, SBR, and NBR used in tire treads, sidewalls, belting and inj. molded goods. 

A product of this type will have over 50% of its weight derived from maleic anliydride. This veiy high content of reactive double bonds will lead to a very brittle solid when it is cross-linked witli styrene. Witliout furtlier modification, this solid material will have veiy high tensile moduli, probably over 600 kpsi, but a very low tensile elongation, way below 1 %. Such a brittle material obviously has only very limited applications. Thus, for most general-puipose applications, it is necessary to incoiporate some chemically inert components to soften tire polymer backbone. This will reduce tire cross-linking density and improve the physical properties of tire cured solid. 

Low-profile additives are generally materials such as poly (vinyl acetate), polystyrene, polyethylene or polycarbonate. During tire unsaturated polyester cure cycle, tire low-profile additives separate into a second phase, which expand to counteract tire shrinkage of the curing unsaturated polyester resin. Material development and tire science of low-profile additives have helped create substantial markets for unsaturated polyesters. Their use in automotive markets, where Class A show room quality surfaces is a requirement, is an example of this. 

Recycling waste tire rubber is such large a problem that it could be covered only by a book entirely devoted to the subject. Eollowing the scope of the present book concerned with the cure of rubbers, only general considerations have been made by giving attention to applications employing, to some extent, the cure process. 

As already said in the Preface, a question arose as to the appropriateness of having a chapter in this book devoted to the cure of rubbers and to their properties concerned with the recovery of scrap rubber obtained from old tires. However, the amount of old tire rubber is so large that it could be considered as a raw material, and reclaiming will become a necessity when crude oil and natural rubber experience shortages. This problem is so vast that only a book in itself could describe all the possibilities of reusing. Nevertheless, a large number of opportunities has been identified, and the reclaiming processes based on the cure of these scrap rubbers have been considered. 

Building on technologies first developed in Germany in the early 1930s, Robert M. Thomas and William J. Sparks, both employees of Standard Oil (now ExxonMobil Chemical), patented a new synthetic rubber in 1937. Butyl rubber is characterized by a very saturated linear polymer chain, leaving little space between molecules for transmission of air, vapors, moisture, or water. As such, butyl rubber was successfully used during World War II as a substitute for natural rubber in the manufacture of tire inner tubes and curing bladders. 

Uses Post vulcanization stabilizer for sulfur cures of NR, IR, SBR, and NBR used in tire treads, sidewalls, and general industrial prods, incl. belting and inj. molded goods bonding promoter for rubber-based steel adhesion Trade Name Synonyms Duralink HTS [Flexsys http //www.fiexsys.com, Harwick Std. Distrib. http //WWW. harwickstandard. com]... 

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