Only in Europe new car registration exceeded 12 million units in 2014. The EU market is diverse, with the most registered brand commanding only 13% of the market. There is a strong competition between these companies to achieve the most innovative products and OEMs are continuously proposing new products to the main TIER 1 companies (Faurecia, Johnson Controls…).
At the present moment, the main concerns about interior systems are focused on:
- Interior system weight reduction and use of environmental friendly materials.
- Total Volatile Organic Compounds (VOC) reduction because the extended exposure has negative health effects including eye, nose and throat irritation, dizziness and headaches.
Both priorities can be faced using Natural Fibre non-woven mats; they combine better biodegradability and low VOC. But they also introduce new challenges related to low specific mechanical strength and odour emission problems due to special structure of the cellulosic natural fibres.
Our previous EKA project has demonstrated two relevant facts:
a) Processing the fibres together with the polypropylene (PP) matrix is accompanied by thermal and mechanical stress. It results in chemical changes both of the secondary components and of the cellulose if the thermal cycle is too severe.
b) To achieve the minimum strength required by OEM is necessary to use large layer thicknesses and this involves high NF weight addition and the use a lot of energy to form the product.
The project HR-Mats proposes to overcome these limitations developing a new composite that combines:
i) Natural fibre and Recycled Carbon Fibre (RCF) blends to increase the specific mechanical resistance and thermal conductivity. Three different R&D lines will be studied:
a) Stacking and needling of non woven single layers made of RCF+NFPP
b) Combination airlaid, cardling, cross lapping and needling techniques of NF+RCF+PP fibres to obtain a non-woven
c) Combination airlaid, cardling, cross lapping and needling techniques of NF+RCF fibres and final impregnation to obtain a prepreg
ii) Chemical modification of polypropylene matrix using maleic acid to improve the interfacial fibre-matrix adhesion and natural fibre bleaching treatments to reduce odours.
The use of RCF by means of multiple layers stacking, mixing and impregnation techniques could also improve the non-woven heating rate during compression moulding process. For this reason, it is proposed a joint development of a new non-woven manufacturing t process and a fast heating-up system in order to maximise the energy efficiency during the forming stage.
All the above mentioned actions can be beneficial to reduce the unfavourable odour and emission behaviour of natural fibre reinforced composites. But they also introduce new insights in this complex matter too. The odour and the emission behaviour do not only depend on the properties of the raw materials and the manufacturing steps but on the fate of the components after processing as well. In this project it is proposed a complementary study in order to determine the effect of the storage conditions (time, temperature, ventilation…), the kind of packaging of the finished component and the assembly situation of the final product.