vantee2001
05-20-2001, 11:35 AM
Proline's M2/3, S2/S3 and Losi's Silver/Gold/Red compounds are actually a blend of primarily Exxon's Butyl Rubber and N990 Carbon Black. This blend/mixture forms the masterbatch (99%) of the entire compound and thus responsible for all the physical properties of the product when vulcanized (while the remaining 1% belongs to the mixture of processed oils/anitoxidants/accelerators/crosslinking agents used to vulcanized the masterbatch via the heated tire mold at around 300 degrees F) . Since Butly rubber has only 0.3% of its mass capable of crosslinking (the majority of Butyl is polyisobutylene, used for making adhesives and gum) this would give the finished product (tires) low rebound and stickiness, much different than tires made out of natural or SBR rubber. The difference in hardness are achieved via the use of processing oils which will render the crosslinked compound harder/softer depending on the types & quantities of oil used. Also, by replacing the N990 carbon black with a much finer one will turn the entire blend into the much harder compound (when vulcanized) and in addition a longer wear, like the ones used to make some onroad street tires. The masterbatch (its formula is not solely owned by any of the tire makers) and the neccesary agents can be purchased from R and S Processing Inc. in California at about US$ 1.45 to1.60 per pound, depending on the quantity purchased. Yes, anyone can buy the compound from R and S if they are interested in making tires. And one can make at least 3 to 4 pairs of an average offroad REAR tire from a pound of this masterbatch. R and S can be reached at : http://www.rsprocessing.com