This thesis looks into the application of self-reinforced polypropylene (SRPP) in a tablet cover for the company Gecko Covers. Gecko Covers is a company that provides protection for devices in the form of covers and sleeves. They are performing at their best in the tablet market.
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This thesis looks into the application of self-reinforced polypropylene (SRPP) in a tablet cover for the company Gecko Covers. Gecko Covers is a company that provides protection for devices in the form of covers and sleeves. They are performing at their best in the tablet market. They would like to enter the impact resistant tablet cover market using an impact cover that is both impact resistant and stylish. Their product style is characterized by the usage of contrast in both material texture and color, simple shapes and an attention to detail. Based on a market analysis, the tablet user on the go is selected as target group. These people carry their tablets with them wherever they go. To differentiate from the current competitors in this tablet market segment, Gecko has to focus on reducing the environmental impact of the new cover by e.g. making it recyclable. The most important material properties for the impact cover are high toughness, low density and a minimum ductile-to-brittle temperature of -20 °C. Not only does SRPP meet these requirements, it is also recyclable as it is only made out of a single type of thermoplastic. The manufacturing process of producing laminates out of woven SRPP influences the material properties such as impact resistance. Literature research shows that a combination of hot compaction and film stacking improves the impact resistance of the SRPP laminate the most. The values of the other parameters which influence the material properties of the laminates were determined through trial and error. To evaluate the SRPP laminates, a bending fatigue test and an alternative Izod impact test were conducted. In the end, the laminates with a compaction temperature of 170 °C, a pressure of 1,73 bar, an active heating time of 5 min and 1 PP film layer in between the SRPP fiber layer are the toughest and ductile. The focus of the design was on a minimum viable product. A back structure inspired by those of suitcases, the screen edge and the regular corners and edges of the cover were all taken into account. To validate that the shape is manufacturable from SRPP, a proof of concept was made with a mold. Furthermore, this proof of concept was tested via a drop test to get more information about the actual performance of the SRPP layer and to determine which orientation would have the highest impact resistance. The drop test showed the importance of the screen edge, which was missing from the proof of concept as it cannot be made out of SRPP. The test also showed that the SRPP lacked damping. To add the screen edge and the damping to the product, additional injection molded PP was used in order to add the screen edge and damping elements to the product. The final design was inspired by natural Voronoi structures and also creates a contrast in material texture and color, matching the current style of Gecko Covers.