Free Newsletter
Register for our Free Newsletters
Advanced Composites
Amorphous Metal Structures
Analysis and Simulation
Asbestos and Substitutes
Associations, Research Organisations and Universities
Automation Equipment
Building Materials
Bulk Handling and Storage
CFCs and Substitutes
View All
Other Carouselweb publications
Carousel Web
Defense File
New Materials
Pro Health Zone
Pro Manufacturing Zone
Pro Security Zone
Web Lec
Pro Engineering Zone

The Methuselah of the footwear world

Bayer MaterialScience AG : 27 April, 2004  (Company News)
Materials scientists from Bayer MaterialScience AG have unveiled a polyester polyurethane that stands out from standard-quality polyurethanes thanks to its greatly increased life span. This development was achieved by successfully slowing down natural aging reactions.
The new long-life grade of polyurethane, christened Bayflex® longlast by the shoe experts in Leverkusen, will go a long way to increasing the scope of safety-shoe manufacturers.

'The diverse range of properties that can now be given to polyurethanes by clever combinations of suitable raw materials is enormous,' says Dr. Eberhard Michels, who is involved in developing new shoe materials at Bayer MaterialScience. 'Polyester polyurethanes are not prone to swelling, offer exceptional tear resistance and excellent abrasion values, therefore making them particularly suitable for manufacturing safety shoes, for instance. That's why the safety sector is dominated mainly by esters.'

Nevertheless, there is a downside to these highly sophisticated materials. Under certain conditions, for example long-term use in a particularly hot and humid climate, polyether polyurethanes, which are generally seen as rivals to polyester polyurethanes, are considered more resistant than the latter. The reason for this is a natural chemical reaction between polyester-based plastics and water, which gradually weakens their molecular structure. And as with every chemical reaction, it speeds up at higher-than-normal temperatures.

'Yet, it isn't all bad news. Chemists have developed methods to slow down this gradual aging reaction considerably,' explains Dr. Michels. Indeed, the experts at Bayer MaterialScience AG have succeeded in developing a technology, for which the patent is pending, that puts the brakes on the aging process for polyester polyurethane used to manufacture soles. This means that the sole materials popular for safety shoes will also have a long service-life. 'And we were able to prove this in intensive climate chamber tests,' confirms Dr. Michels.

'These anti-aging properties are an efficient and cost-effective feature of our Bayflex® longlast system which we will be offering to customers initially for the Bayflex® safety and active ranges only.' At the same time, manufacturers still benefit from all the advantages of polyurethane technology. Like the other Bayflex® products, the new material is suitable for manufacturing soles using the casting process and for high-productivity direct soling. Adhesion to other soling materials such as rubber, TPU and leather is as good as ever, meaning complex adhesive bonds are unnecessary. Even in terms of its physical properties, the new material is on a par with 'simple' polyester polyurethanes.

'A development like this can only be expected from a manufacturer with recognized experience of research in the field of polyurethanes. And of course, polyurethanes were first developed in Leverkusen and Bayer has more than five decades of expertise working with these materials,' says Dr. Michels, in conclusion. The new long-life polyurethane has been proving its worth in service for over six months now.
Bookmark and Share
Home I Editor's Blog I News by Zone I News by Date I News by Category I Special Reports I Directory I Events I Advertise I Submit Your News I About Us I Guides
   Â© 2012
Netgains Logo