A bizarre image looms into view of a dairy cow comfortably relaxing on a bed of scrap tires. The animal’s well-being results in higher productivity and the farmer is happy at the increase in milk production. Admittedly, the cow isn’t sitting directly on the tires. But scrap rubber can be processed into a material that is valuable from the ecological viewpoint and can be used to produce articles such as comfort mats for livestock. These simulate lying conditions in the cowshed, which are similar to those on pasture.
“Under natural conditions a cow spends about 60 percent of its time reclining. In this position the blood flow to the mammary gland increases by up to 30 percent, allowing increased milk synthesis,” explains Dr. Winfried Heimbeck, Expert for ruminant nutrition at Evonik. “So the greater the comfort the cow can enjoy in the shed, and the more time it spends reclining, the more productive it will be. If you expand the reclining time of a cow by one hour, it can produce up to 1.5 kilograms more milk a day.”
But if the cow’s joints ache after it has reclined for long, the animal stands up. This reduces rumination and the intake of water and food. Special cow mattresses increase the cows’ well-being by improving reclining comfort, preventing hock injuries, and serving as thermal insulation.
More efficiency in rubber recycling
For a cow mattress to offer sufficient comfort over a lifetime of many years it must be made from an enormously tough material that can withstand the considerable weight of the animal and the humidity in the cowshed. On the other hand, the cow mattress must not shift under the huge weight and must be easy to clean yet have a springy feel. Cow mattresses from recycled scrap rubber satisfy all these requirements. Evonik’s VESTENAMER® process additive ensures the right balance of properties in the recycled material.
In the recycling of scrap rubber, the addition of VESTENAMER® is an application that has already proven its worth in the production from useful waste of rubber articles such as floor coverings, mats, and stand systems for signposting of road works and barriers.
“As a process additive VESTENAMER® improves the flowability of the rubber compound, as a result of which the material can be processed much more efficiently. The reactivity and polymer structure of VESTENAMER® are also important here: Both lead to a good network density between the rubber particles. This in turn positively impacts the mechanical properties,” says Dr. Peter Hannen, market development manager for VESTENAMER®. “In short, Evonik’s process additive improves both the cost effectiveness of processing and the quality of the rubber parts when rubber is recycled.”
Significant reduction in carbon footprint
In addition to the economic aspect of providing a cost-efficient raw material, the material recycling of scrap tires is also becoming more important from the ecological viewpoint. For example, the use of scrap tire granulate in new products contributes significantly toward reducing the carbon footprint by up to one third as compared with products that do not use a recycled material.
And the closed circular economy of rubber also alleviates the global scrap-tire problem. Every year, about 19.3 million metric tonnes of scrap tires are generated worldwide, more than 3.6 million metric tonnes of them in Europe alone.
The use of rubber granulate is becoming increasingly important in a variety of applications such as road construction, sports grounds and playgrounds, and new rubber products. Twenty years ago, for example, more than half the used tires in Germany alone were used for energy recovery, with only one in ten being processed to granulate by material recycling. But material recycling is now on a par with energy recovery; in Germany, every third scrap tire on average now gets a new lease of life as recycled “rubber granulate”—which is good news, and not only for the cows.
VESTENAMER® has been used as a process additive from Evonik in the rubber industry for many years. Manufactured in the Marl Chemical Park (Germany), the polyoctenamer solves a number of different challenges in the compounding and processing of rubber; It is also used as an aid in the recycling of waste rubber.