Serving as extravagant status symbols or simple supports for every step we take, shoes reveal a lot about their wearers’ attitudes and lifestyles, as well as about the current zeitgeist. Whereas Neanderthals still wrapped animal hides around their feet and calves, the Romans wore sandals of a type that is fashionable again today.
More than just footwear
Heeled shoes began to become widespread in Europe in the 17th century. In fact, high heels which are generally found today only on ladies’ shoes, were more commonly worn by men back then. From high heels to sneakers and work boots, there is an almost limitless variety of footwear available today. And in fact, shoes today almost always contain products from LANXESS. The specialty chemicals company develops innovative materials and additives for making shoes more durable, comfortable, stylish, and healthy.
Leather – LANXESS takes the lead
Take leather for example. This natural material is very important for shoes. More than half of the hides processed worldwide (from calf leather to crocodile skins) are used for boots, slippers, and other types of footwear. Products from LANXESS’ Leather (LEA) business unit help to process this material. This business unit offers a wide range of inorganic and synthetic tanning agents, preservatives, lubricants, dyes and pigments, and aids for tanning and dressing leather. “I would go so far as to say that every shoe contains a bit of LANXESS,” says Frank Paus, Vice President Marketing & Sales at LANXESS Leather.
For example, the innovative resin tanning agent Retingan ZF Plus, which doesn’t contain any free formaldehyde, can be used to ensure the upper leathers of fashionable shoes are embossed in an especially uniform manner. Baykanol Licker, meanwhile, softens the leather in the post-tanning stage and ensures that the leather is uniformly colored and has a soft, pleasant feel. The X-Grade system developed by LANXESS is used during the finishing stage (also known as “dressing”), creating new opportunities for concealing small faults such as holes or tears and substantially increasing the amount of leather that can be effectively used.
The challenges of environmental protection
The chemical company develops its products in line with the needs of its customers from the leather industry while also taking environmental protection into account. The tanning process in particular has always been considered potentially damaging to the environment and human health. But LANXESS wants to show this doesn’t have to be the case, which is why it launched the Sustainable Leather Management initiative early this year. “We want to show our support for sustainable, environmentally compatible products and processes in the leather industry,” says Dr. Dietrich Tegtmeyer, Vice President Product Development and Application at the Leather business unit. Among other things, the company is using production processes that minimize contamination of wastewater and also developing tanning systems containing non-toxic, organic chemicals.
Rubber – versatile and functional
“Burn rubber”: Besides leather, modern synthetic rubber from LANXESS is another key material used in shoe production. The material, which is mainly used to make car tires, gives shoes flexibility and a firm grip. Hiking shoes with rubber soles are considered especially slip-resistant and sure-footed. Synthetic rubber also shows what it can do wherever reliable protection is needed in the workplace. For example, boots made of oil-resistant NBR rubber products from LANXESS protect their wearers against oil, fuel, and other corrosive substances. The soles of firefighting, construction, and protective boots are often made of SBR rubber or of the XNBR rubber Krynac® X. This material is resistant to oil, acid, and lye, while also being skid-proof and resistant to wear and tear.
Ultra-light summer feeling
Hardly anyone is outdoors during the summer months without rubber soles. The best examples are the popular “flip-flops,” which are often made of synthetic rubber from LANXESS. Among the examples of this are Havaianas, of which around 160 million pairs are manufactured in Brazil every year. In addition to their funky design, the flip-flops’ highly elastic, comfortable and durable soles help put their wearers in a good mood.
Regardless of whether people use shoes for work or play, they benefit from LANXESS’ more than 100 years of experience as a manufacturer of synthetic rubber. In 1909 the chemist Fritz Hofmann managed to develop the first procedure for making the artificial elastomer material. As the inventor’s heir, LANXESS is a byword for innovative ideas to the present day. LANXESS is investing in research and continuously improving its rubber recipes in order to help make the end products as functional as possible.
Sports shoes – high performance every step of the way
Whenever athletes pull out all the stops, their shoes also have to be in top form, and the materials they contain have to show their stuff. The stresses caused by jogging, for example, are about three times greater than the jogger’s body weight. Sports shoes equipped with midsoles made of modern, high-performance rubber serve as a buffer between the jogger’s feet and the hard running surface. “Special types of rubber from LANXESS can store this deformation energy and give it back without any significant loss, thus providing athletes with ideal support,” says Martin Mezger, a rubber expert at LANXESS. The specialty chemicals company has developed an ethylene vinyl acetate rubber known as Levapren, whose special structure allows it to meet all of the requirements of leisure and sports shoes. This special rubber demonstrates its shock-absorbing and stabilizing properties particularly in the midsole, which is at the heart of all of today’s running shoes. During the manufacturing process, the granular synthetic rubber is at first mixed with filling materials and crosslinking and foaming agents, after which it is kneaded and rolled. Under the effect of heat, the mass is then foamed into blocks, which creates many small gas bubbles in the material. In combination with the properties of the rubber, these bubbles produce the desired result.
Another special type of rubber from LANXESS ensures that shoes have a good grip even on moist surfaces. Running shoes with soles made of Krynac brand acrylonitrile butadiene rubber are especially durable and resistant to wear and tear, while also being flexible. Various parts of the sole have flex zone indentations that increase its pliability and thus enhance the impact properties when running. The grip is further improved by a distinctive kind of ribbing.
LANXESS is also concerned about the feet of its employees, and it once again has contributed the biggest group of runners (approximately 600) to the EVL Energieversorgung’s half marathon in the specialty chemical company’s home town of Leverkusen in 2011. All of the participants who crossed the finish line received Adidas running shoes bearing the Group’s colors and, of course, containing LANXESS rubber in the soles.