Video Exclusives


Michelin connected tires

Sentury

The OEM has introduced a connected tire in motorsport, which enables drivers to monitor and control tire temperature and pressure in real time.

Click here to watch the video


Proving ground expansion

Sentury

Millbrook is expanding its Test World facility in Finland...

Click here to watch the video


A day in the life of...

Sentury

This short clip provides a glimpse into what's it like to be a Goodyear test driver

Click here to watch the video


Can you name this young Scottish visionary engineer who invented the pneumatic tire, decades before John Boyd Dunlop made a commercial success of it?

Industry Opinion

« back to blog listings

Assisting an agent

Compatible with all sorts of rubber, naphthenic oil facilitates the dispersion of insoluble sulfur, the vulcanizing agent used in the production of tire rubber. Anna Eriksson, Nynas Naphthenics technical manager, explains how this helps improve the quality of the final rubber.

Sulfur is used as a cross-linking agent during the vulcanization of rubber, and although ordinary sulfur is the most commonly used vulcanizing agent, many producers, especially those that make tire rubber, prefer to use insoluble sulfur.

“This is because insoluble sulfur avoids issues related to migration,” explains Anna Eriksson, technical manager – chemical industry, Nynas Naphthenics.

Migration or ‘sulfur bloom’ refers to the crystallization of sulfur on the surface of rubber. This occurs because normal sulfur is soluble and will dissolve within the rubber. When the rubber is heated during the vulcanization process the sulfur can migrate to the surface, where it will crystallize as the rubber cools. For tire rubber and other high-end rubber products, sulfur bloom will cause problems in subsequent processing steps.

Arranged in rings of eight sulfur atoms, normal soluble sulfur is made insoluble in a process that sees it first heated and then quickly cooled. This fuses the S8 rings into long polymeric and insoluble chains. However, insoluble sulfur tends to revert back to the soluble non-polymeric form quite quickly, unless it is kept dispersed in an oil.

“Naphthenic oil is particularly suitable for this purpose as it efficiently prevents reversion back to the soluble form. At the same time, it also enables the curing agent, in this case insoluble sulfur, to be properly incorporated into a wide selection of rubber.

"Naphthenic oil is highly compatible with all sorts of rubber compounds, facilitating the dispersion of sulfur and ensuring a good cross-linking density in the final rubber goods,” explains Eriksson.

The most commonly used oil has a viscosity around 22cSt (at 40°C), and the amount of oil varies between 10% and 40%. Offering high compatibility with a broad range of elastomers, high solvent power and non-staining behavior, Nytex 810 is widely used by producers.

Anna Eriksson, technical manager, chemical industry, at Nynas Naphthenics is a chemical engineer specialized in polymer technology. She joined Nynas in 2006 and coordinates technical activities with industry customers, academia, test institutes and authorities. 

March 28, 2018

 

 

Comments:

There are currently no comments.

If you would like to post a comment about this blog, please click here.
RECEIVE THE
LATEST NEWS


Your email address:



Read Latest Issue

Read Latest Issue

Read Latest Issue

Web Exclusives

Completely truckworthy
Bridgestone America's director for commercial tire development, Mitchel Kritzell, gives an update on the SuperTruck II program
Read Now

Q&A: Sam Visaisouk, CEO, Tyromer
The Retread Tire Association (RTA) speaks with Tyromer CEO, Sam Visaisouk, about the testing of its new tire-derived polymer recycled rubber product in truck and passenger car tires
Read Now

Q&A: Chris Bitsakakis, AirBoss
The Retread Tire Association speaks with Chris Bitsakakis, chief operating officer and president of the rubber solutions division at AirBoss, about the partnership with Tyromer Inc. to develop a tire-derived polymer recycled rubber product
Read Now

Yokohama installs new ice test track
Operations are now in full swing at Yokohama’s new indoor ice test facility, located at the company’s Tire Test Center of Hokkaido in Asahikawa City, Japan
Read Now

Bridgestone Americas and Versalis in partnership
The two companies have revealed their plans to develop a technology package with the aim of commercializing guayule
Read Now


Supplier Spotlight

Supplier SpotlightWe are building a list of leading suppliers covering all aspects of the tire industry. Want to see your company included? Contact olivia.campbell@ukimediaevents.com for more details.

Submit your industry opinion

Industry BlogDo you have an opinion you'd like to share with the tire technology community? We'd like to hear your views and opinions on the leading issues shaping the industry. Share your comments by sending up to 500 words to rachel.evans@ukimediaevents.com

Submit Your Recruitment Ad

Recruitment AdTo send us your recruitment advertising or to receive information on placing a banner please email olivia.campbell@ukimediaevents.com