Skip to main content

Development of an innovative recycling process based in cryogenic and water jet grinding and sintering techniques for extending the use of recycled rubber in the development of high quality products.

Final Report Summary - CRIOSINTER (Development of an innovative recycling process based in cryogenic and water jet grinding and sintering techniques for extending the use of recycled rubber...)

Nowadays, an enormous quantity of used tyres is land-filled which is one of the main environmental problems worldwide. Only 24 % of used tyres is recycled, mostly in low demanding, low price products, that yield low economical profit, stopping R&D investment (most companies along the recycled rubber supply chain are SMEs). As a consequence, the main use of tyres is as fuel substituting one environmental problem for another due to emissions.

The main goal of this project was to develop an innovative recycling process for producing recycled raw rubber with enough quality for competing with virgin rubber in high demanding products. It will be achieved by integrating emerging grinding technologies, new transformation processes and new materials design technologies.

Products considered in the project are shoes, floorings and automotive applications. The partial goals are scheduled:
- studying the possibility of the optimisation of cryogenic and mechanical technology by controlling the morphology or another grain characterisation property such as size in order to be able to optimise the obtained properties.
- development of procedures for optimising pressure-temperature sintering.
- development a use-oriented material design methodology allowing translation of product requirements into product properties.
- identifying emotional requirements to be translated into recycled products.
- integration of above results in a process for producing high added value products from scrap tyres.

The project objectives followed two approaches: the first comes from the raw material knowledge and the sintering process while the second approach comes from the end user and market expectation.

Cryogenic and mechanical grinding has allowed determining control parameters for a pre-sintering compound that have to be used in order to get a specific value of a determined property. The injection- compression sintering process has been studied and a rubber-injection moulding machine has been employed in order to do the scale up of the injection compression process. Knowing the control parameters of a pre-sintering compound and the control parameters of the sintering process, a optimisation of the sintering procedure has been carried out obtaining as a result an expert system which is able to optimise the resources involved in order to obtain a sintering rubber with the selected level of properties achievement depending on the final application where it is going to be used. Technical specifications for target application products and priority characterisation into three levels: basic, linear and overquality specifications. A strategic plan for raw recycled products and supply chain was developed and the SWOT analysis of the supply chain obtained.

Emotional engineering has also been taken into account for solving the existent barriers that recycled products find in its introduction into a high demanding sector. In order to aid the product introduction, a label that outlines the advantages of the recycled rubber has been developed. Cryogenic rubber has proved to obtain better results in terms of odour improvement. Three end products of the following high demanding sectors: shoes, floors, and automotive components have been developed. They have been submitted to a battery of test in order to determine its requirements achievement in order to be introduced into a high demanding market and the results were very promising.

Exploitable knowledge emerged from the project was divided in two main groups: knowledge having a future potential for further research activities which will permit industrial application, and knowledge transferred to the SMEs involved in the project, that will be exploited throughout their commercial routes and channels.

During all the project duration, the public side of the web site has been used as a dissemination platform. In addition, the project has been presented in different European forums, as European congresses such as the European Tyre Recycling Association conference (2006 and 2007) and the Ecomondo Fair where a poster of CRIOSINTER was placed on the ETRA stand.

Related documents