Non-Marking Shoes: What is the Rubber Treatment?

[Andy Resnick]

My wife just got a new pair of sneakers with black soles that have a 'non marking' designation. Anyone know how the rubber is treated to be 'non marking'?

For those that don't understand, 'non marking' means that the soles won't leave black skid marks on gym floors etc. when cavorting about.

 

[chemisttree]

Thermoplastic rubber leaves black marks. Crosslinked (thermoset) rubbers don't mark.

 

[quicknote]

I can provide some insight into the rubber treatment used in non-marking shoes. Non-marking shoes are typically made with a special type of rubber called "gum rubber" or "non-marking rubber." This type of rubber is softer and less abrasive than traditional rubber, making it less likely to leave marks on floors.

In addition to the type of rubber used, the process of vulcanization is also key in creating non-marking shoes. Vulcanization is a chemical process that involves treating rubber with sulfur and heat to increase its strength, durability, and elasticity. This process also helps to reduce the amount of carbon black (a common ingredient in rubber that can leave marks) in the rubber.

Another factor that contributes to the non-marking quality of these shoes is the tread pattern on the sole. Shoes with deep, aggressive treads are more likely to leave marks, while shoes with a smoother, flatter tread pattern will have less impact on surfaces.

It's important to note that while non-marking shoes are designed to minimize the risk of leaving marks, they may still leave some residue on certain surfaces. This can be due to a variety of factors such as the type and condition of the surface, the type of activity being performed, and the amount of pressure applied to the sole.

In conclusion, the rubber treatment used in non-marking shoes involves a combination of using a softer, less abrasive rubber, vulcanization, and a specific tread pattern on the sole. These factors work together to create a shoe that is less likely to leave marks on surfaces, making them a popular choice for activities such as indoor sports and dancing.