Ambient grinding

Ambient grinding involves the comminution of scrap rubber, including tires, at ambient temperatures, typically in a toothed-wheel mill, bench grinder, shear mill, or two-roll miU, to give particles... 

There are three main methods for producing crumb rubber dry ambient grinding, wet grinding, and... 

Zirconia toughened alumina Press Air sintering 1,400-1,500 Ambient Grinding... 

In order to be used as a filler in polymer composites, tires are first ground into a fine powder on the order of 100-400 im. This is accomplished typically through either cryogenic or ambient grinding. General reviews of the size-reduction process have been published. A typical process generally involves tire splitters to cut the tire initially, followed by a two-roll grooved-rubber mill or hammer... 

Workers in Brazil [98] have recovered scraps of industrial SBR waste and then, after preparing crumb from them by an ambient grinding process, employed microwaves to devulcanise the rubber. Once devulcanised, the vulcanisation behaviour of the rubber was determined by oscillatory disk rheometry and samples vulcanised with and without a post-cure. The samples were then tested so that their mechanical and crosslink densities could be compared. 

If the starting material is a composite one, such as tyres, it has been found that ambient grinding processes tend not to remove as much fabric and metal from the final crumb product as cryogenic processes. For example, an ambient ground rubber has been found to have a fibre content of 0.5% and a steel content of 0.1%, whereas that produced by a cryogenic process had levels below the detection limit for these two components [10, 11]. 

A novel variant on ambient grinding technologies was described by Asadauskas and co-workers [15] at the Tire Technology 2014 event in Cologne. In this high-shear process, both mechanochemically effective and tribologically effective additives are employed. These additives are claimed to provide the following twin benefits ... 

With regard to the manufacture of crumb using ambient grinding-type processes, the BSI has published a PAS for the collection, initial storage, production and final storage of size-reduced, tyre-derived rubber materials. It is designated PAS 107 2007. This document has already been referred to in Section 6.4.1 in connection with quality protocols that apply to rubber crumb. 

Table 6.2 Rubber crumb produced by an ambient grinding process ...

---