Characterization of thermoplastic vulcanizates (TPV) products for automobile weatherstrips on different conditions

The aim of this study is the preparation of thermoplastic vulcanizate (TPV) materials based on different process conditions and characterization. TPV materials are widely used in automotive industry. In addition, the automotive Original Equipment Manufacturers (OEMs) are requested some performance tests defined in their technical specifications. The weatherstrip, inner parts, which are produced for a Japanese Company, were used to be able to obtain test samples. The test samples were produced on different process conditions such as extruder clamp temperature, cooling time and cooling temperature. The test samples were characterized as structural, mechanical-heat aging properties and thermal properties via OEM technical specification, optical microscope, DSC and TGA test equipment, but also the effects of extruder clamp temperature, cooling time and cooling temperature were studied. As a result, it was seen that cooling temperature was an important parameter for crystallization when structural properties were compared via optical microscope images. Also, when mechanical-heat aging properties were analysed with compression load, compression set, low temperature resistance, paint film staining resistance, glass surface stain adhesion and whitening tests, there was contamination on the painted plate surface at 210 °C. As the cooling water temperature was increased, compression load test results decreased. When the cooling time decreased, hardness and compression load decreased while compression set increased. Due to the test results are close to each other. The thermal decomposition was performed under nitrogen atmosphere from 40 °C to 600 °C at a heating rate of 20 °C/min. According to results, there was two-step decomposition. Firstly, polypropylene started to lose weight at 300 °C. Compared to the eight samples examined with the TGA, there was a difference in the amount of ashes of the samples obtained at different cooling times. This difference can be interpreted to be due to non-homogeneous vulcanization. DSC analyses of profiles were performed with selected profiles. In this thesis, different cooling rates were studied as 10 °C/min and 20 °C/min. All samples were heated from 25 °C to 300 °C by heating rate of 10°C/min. Then, all samples were cooled from 300 °C to approximately 25 °C. In this analysis, melting temperature, heat of fusion, crystallization temperature and heat of crystallization was tried to analysed via obtained curves. But, glass transition temperature, could not be seen clearly. A few of melting and crystallization peaks were observed due to consisting of PP and EPDM. The melting temperature was observed between 150 and 155 °C whereas crystallization temperature was between 105 and 110 °C. This study is important to solve encountered co-extrusion line problems such as whitening and low compression values. Energy loss and scraps increase due to these problems while productivity decreases. This reflects a significant cost increase problem for the company. To be able to solve those problems, the co-extrusion lines can be improved with studied parameters, especially cooling temperature.