Tyre compounding technology

New mixing methods combining a Banbury mixer and open roll mixing which have been used for the production of tyre compounds are studied and compared. 3 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. 

The optimising of a tyre compound to improve reversion resistance is discussed with reference to the use of two new rubber chemicals developed by Flexsys. They are 1,3 bis(citraconimidomethyl benzene) (BMI-MX) and hexamethylene-1,6-bisthiosulphate disodium salt dihydrate (HTS), which are claimed to provide two different ways to improve the thermal ageing resistance of sulphur-based vulcanisates as compared to existing technology. Each functions by uniquely different mechanisms of action and each provides different levels of performance improvements. A comparison is made of HTS and BCI-MXto conventional cure systems and semiefficient cure systems to illustrate the potential benefits of these approaches to address reversion in tyre compounds. 5 refs. 

Bandyopadhyay S., S. Dasgupta, N. Mandal et al. 2005. Use of recycled tyre material in natural rubber based tyre tread cap compound Part 1 (with ground crumb mbber). Progress in Rubber, Plastics and Recycling Technology. 21(4) 299-317. 

This chapter will discuss the state-of-the-art of bonding rubber compounds to brass, a technology primarily used on steel tyre cords. The literature is reviewed since 1991 when the previous review was published [1]. An updated mechanism for the rubber adhesion mechanism of brass is presented. Some new developments, such as proposed alternatives to brass, are also discussed. 

The scale-up goal was achieved and the DevulCOi devulcanisation technology was successfully transferred to a number of sulfur-cured rubbers, including nitrile rubber, EPDM rubber and NR. In addition, the results of the evaluation of the performance of the DevulCOi rubber in tyre retread compounds were encouraging. A more extensive description of these two projects and the results of the manufacturing trials that were imdertaken during them, is provided in Chapter 5, Section 5.2.2.I. 

Roy and co-workers [57] at the Indian Institute of Technology have evaluated the performance and the chemical behaviour of a range of disulfide compounds when applied to waste tyre rubber. The DR that were obtained in each case were revulcanised to assess their cure characteristics, and then samples tested to determine their mechanical properties, morphology, dynamic properties and thermal stability. 

The properties of the fine, devulcanised rubber crumb that results from the process varies according to the types of additives used and their levels, and the crumb has been shown to be used effectively to replace virgin rubber in new rubber compounds. For example, experimental trials have been undertaken with rubber crumb obtained using this technology from car tyre treads incorporated into SBR compounds. The results that were obtained on the resulting vulcanisates were compared to those produced using conventional rubber of the same... 

As has been mentioned in Chapter 2, these are much older technologies, initially developed in the 19 century, that were only originally designed to reclaim tyre rubber in some form for re-use as an additive in fresh compound. The three main processes of this type are as follows ... 

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