Each year throughout the world, up to 22 million tons of rubber are processed and a large portion of it goes into the production of vehicle tires. Once the products reach the end of their useful life, they typically land in the incinerator. In the best case, the waste rubber is recycled into secondary products.
Elastomeric powders can be used in a variety of ways in high-quality materials.
© Fraunhofer UMSICHT
Ground to powder, the rubber residues can be found, for example, in the floor coverings used at sports arenas and playgrounds, and in doormats. But until now, the appropriate techniques for producing high-quality materials from these recyclables did not exist. Researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen recently succeeded in optimizing the recycling of rubber waste materials. They have developed a material that can be processed into high-quality products, like wheel and splashguard covers, handles, knobs and steerable castors.
The new plastic compounds are called elastomer powder modified thermoplastics or EPMT for short. They are comprised of rubber residues crushed into elastomer powder that are blended with thermoplastics. “In the first step, the rubber residues – that can be meter-long rubber pieces are granulated to three-millimeter large particles. The particles are cooled with liquid nitrogen and then ground into elastomeric powders. This is then conducted to the melt-mix process with thermoplastics and additives. Here we use, for example, polypropylene as a thermoplastic material,” as Dr. Holger Wack, scientist at UMSICHT, explains the production process. Working jointly with his colleagues Damian Hintemann and Nina Kloster, the trio collaborates on the “EXIST Research Transfer” project sponsored by the Federal Ministry for Economics and Technology BMWi, where they work meticulously on various recipes for new blends of materials that are already protected by patent and trademark rights.
Variable material properties
The compound stands out from a number of different perspectives: The crushing of rubber waste is more environmentally-friendly and resource-efficient than producing new rubber products – an important aspect in view of the rising costs of energy and raw materials. “EPMT may contain up to 80 percent residual rubber; only 20 percent is made up by the thermoplastics,” says Wack. EPMT can be easily processed in injection molding and extrusion machines, and in turn, these products are themselves recyclable. The clou: The physical and mechanical material properties of the substance – like elasticity, breaking strain and hardness – can be individually modified, according to the customer’s wishes.
Altogether, three basic recipes have been developed that collectively can be processed on the large technical production machines. The researchers are capable of producing 100 to 350 kilograms of EPMT per hour. Spurred on by this success, Wack and both of his colleagues founded Ruhr Compounds GmbH. In addition to the production and the sale of EPMT materials, this Fraunhofer spin-off offers custom-made service packages: “We determine which of the customer’s materials can be replaced by EPMT, develop customized recipes and also take into account the settings required at our customers‘ industrial facilities,” says the scientist.
The widest array of industries will benefit from the expertise of these professionals: processors of thermoplastic elastomers can obtain EPMT and further process it into products. Industrial companies whose work involves elastomers – such as the industrial and construction sectors, or car-makers and athletics – could recycle these products, make EPMT from them, incorporate them into their existing products and thereby close the materials cycle.
Nike tests EPMT
In the “Re-use a Shoe” project, sports gear maker Nike has been collecting used sneakers for a while now, recycled their soles and under the label “Nike Grind”, reprocessed them as filler material for sports arenas and running track surfaces. The EPMT compound of the Fraunhofer researchers enables Nike to place new products on the market. As one of its official promotional partners, “Tim Green Gifts” created the first EPMT-based promotional articles under the “Nike Grind” brand, like frisbees, shoehorns and boomerangs. Discussions about using new EPMT compounds in the original portfolio, such as zippers, bag bases and sports equipment, have also been initiated. “We are extremely excited about this collaboration,” says Wack.
Dr. rer. nat. Holger Wack | EurekAlert!
Beyond conventional solution-process for 2-D heterostructure
22.06.2018 | Science China Press
Graphene assembled film shows higher thermal conductivity than graphite film
22.06.2018 | Chalmers University of Technology
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences