How many times have I heard that the rubber used to produce low-end tires is likely to be synthetic… and up until recently, I thought so too, but it’s not the case! The truth is that Natural Rubber (Natural Rubber = NR) comes from a tree (Rubber Tree = Hevea), it’s listed on the stock exchange and its properties will vary depending on various factors, somewhat similar to maple syrup… In the case of synthetic rubber (Styrene-Butadiene Rubber = SBR) it’s chemically engineered. Although its properties slightly differ from natural rubber, it’s in no way of bad quality… What are the factors that have an impact on the quality of rubber?

You will find below an example of the components used in the manufacture of tires. It always starts with the mixing stage where ingredients are carefully prepared in precise quantities in order to obtain the rubber properties required.

Here’s a list of factors (which is moreover quite incomplete) that will have a direct impact on the quality of the rubber produced:

1. Quality of the ingredients : The chemicals used will vary greatly in cost among other things, by the variability of their properties, but also by their characteristics. Thus, the size of the particles becomes crucial, and of course, if you want a stable product, you must be ready to pay the price!
2. Quality of mixing : When you want to save, nothing better than cutting on mixing. It’s similar to a cake recipe, if ingredients are not mixed properly, the dough won’t raise… The same applies to rubber. Ingredients that are mixed rapidly will result in inconsistent properties.
3. The recipe :
   • Generally speaking, we’re looking for the following features in a tire: ozone-resistant, a tread that is abrasion-resistant, a good sidewall flex, etc. In order to obtain these properties, certain substances will need to be added and for example, could resurface during tire aging process.
   • When moulding rubber, in fact, we try to fill the mould… Therefore, if we really want to lower the cost, we need to make sure that the cost to fill this volume is as low as possible. To make it possible, ‘’filling agents’’ must be used. For example, in certain cases, manufacturers will add rubber powder coming from old tires or clay… However, it’s generally done to the detriment of the physical properties of the final product. The result, poor quality rubber…

As you can see, rubber is a fascinating product on which we can still learn a lot! This newsletter is just an overview that outlines the complexity of rubber …

The LanOTR team.