Project: Development of micro-blasting by high pressure water jet technology for recycling rubber to use for thermoplastic compounding

One of today most important problems is the environmental pollution. Several projects are aimed to reduce pollution and, among others, decrease the amount of waste. _x000D__x000D_According to ETRMA (European Tyres and Rubber Manufacturers Association), every year about 3.4 million tonnes of used tyres (part worn + end of life tyres) are generated in Europe, of which 3 million tonnes are either recycled or recovered. This amounts to approximately 300 million units._x000D__x000D_There are 700 companies in Europe recycling used tyres producing 1,2 millions tones/year of granulates. The energy consume needed to produce a recycled rubber product (from raw material to production) is around 66% less than when it is produced with non-recycled aggregates; and a 47% less referering to greenhouse effect gases._x000D__x000D_There is significant amount of elastic waste which is today recycled mostly by grinding. The CO disadvantage of today commonly applied technologies to recycle elastic waste is that during the grinding process heat develops at the surface of the granule. The presence of the heat leads to surface oxidation of the granules. This oxide layer prevents the usage of the recycled granules as raw material. It can be used only as additive (up to a few %) when mixing with elastic and rubber, and only after surface treatment of the granule._x000D__x000D_The base of the high pressure water jet technology has been developed by the experts of MICRO EUROPE Ltd. The results of this work evidence benefits over the existing technologies. With the new Micro-Blasting grinding by High-pressure Water-jet technology (will be referred as MBHW), which will be improved and applied to develop a pre-industrial prototype within the GreenRubber project, the elastic waste can be ground more efficiently. The specifical surface of the granule without oxide layer is much larger than obtained by the existing means. These improved parameters make possible the usage of the granule as raw material (up to 40%) by mixing it with primary materials such as rubber or thermoplastics._x000D__x000D_With this new technology elastic waste is ground at ambient temperature, without heat developing at the granule surface. The grinding process is performed by high pressure water jet, which enters the elastic material and, so to speak, blasts it. The granule recycled with this technology has large specifical and oxide free surface and thus they act, without need of surface treatment, as active particles when mixing with other materials._x000D__x000D_As a result of the GreenRubber project a new, more economic and more efficient technology to recycle rubber and other elastic material waste will be obtained, in such a way that this recycled granule can be used more extensively than the existing recycled granules, which will lead to an important reduction of the environment pollution. _x000D__x000D_The first step of the GreenRubber project will be to evaluate the different parameters involved in the MBHW technology with a Water Jet research equipment. Tests will be conducted under different process parameters (water pressure, jet distance, advancing speed,…) and the resulting rubber granule will be characterized. The results obtained within the tests will be used to design and construct a pre-industrial recycling prototype._x000D_In order to prove that the recycled waste can be effectively used as raw material, several extrusion-compounding tests will be carried out. From the results of the tests the suitable thermoplastic/greenrubber compounding can be determined. These tests will consist of the design of the different formulations, development of the compound and the subsequent characterization of the blends._x000D__x000D_Once the samples are characterized, injection molding process will be used to study the processability of the innovative compounds. The injection molding process will allow to determine the suitable applications for the developed GreenRubber compounds. _x000D__x000D_At the end of the project the development and patent of the new equipment to be used industrially to recycle rubber and other elastic material is expected. _x000D__x000D_As a result of the GreenRubber project, extensive knowledge will be gained to produce intelligent micro-granules, which could be used as raw material for new products. Following the successful ending of the project the new recycling technology and the technological proposals for the application of the recycled material will be introduced into the market, leading to an important reduction in environmental pollution produced by rubber waste._x000D__x000D_The project will be carried out by the experts of the consortium members, MICRO EUROPE Ltd. (Hungary) and Zicla Ltd. (Spain). The GreenRubber project objectives will be accomplished through the rich knowledge of the consortium members about elastic waste and their national and international experiences._x000D__x000D_The expertise, the vocation and joint effort of the members of the consortium guarantees the successful achievement of the project.

Acronym GreenRubber (Reference Number: 6130)
Duration 06/06/2011 - 31/05/2013
Project Topic The objectives are to increase the effectiveness of the new 'micro-blast grinding by high pressure water jet' technology, to design and build the recycling equipment. New applications, based on the innovative thermoplastic/rubber compound developed within the project, will be localized.
Project Results
(after finalisation)
The results of the project were the development of high pressure micro-blasting process and the relating equipments, the construction of the equipments, which can effectively recycle waste tyres and the resulting rubber powder can be used as raw material in thermoplastic mixtures. In the course of the work phases we defined the effect of the technological parameters (water pressure, feeding, swinging, nozzle size, etc) on the specifics of the rubber particles (size, distribution, role in the binding) by means of test grindings. It led to the design and construction of the necessary special equipements of the process: equipment to produce high pressure working fluid, three-phase-cutter, micro-blasting grinding machine. _x000D__x000D_Supported by a foreign (Chinese) potential P we could put into line a „min” pilot plant to present the industrial use of the process. Our Chinese P provided a high performance high pressure pump, a centrifuge and a drying-classifying line. These equipments were connected with the special machines built in the frame of the project by Micro Europe Ltd. into a complex technological line and adding the necessary storing, conveying, cooling, water treating, etc. units we completed the pilot plant. _x000D__x000D_With the operational technology we seperated the tread of bus tyres and the rubber powder produced by grinding it was tested by our consortium P (ZICLA Ltd, Barcelona, Spain) to find the recipes of the mixture of the thermoplastic and the rubber powder. The results of the tests proved that the rubber particles have big specific surfaces, no oxidation occurs due to the technology so they are very active in binding to other materials. Based on the mechanical test results of the rubber/plastic compaunds with various % content industial sample pieces were also molded. As a result of the project we have now a pilot plant which can prove the functionality of the micro-blasting process and we have application techniques results about how to use the recycled powder as raw material.
Network Eurostars
Call Eurostars Cut-Off 5

Project partner

Number Name Role Country
2 El Almacén del Producto Reciclado, s.l. Partner Spain
2 Micro Europe Kft. Coordinator Hungary