Development of a New Product Using Fibres from Recycled Tires

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Yim, Caitlyn
Nwadike, Chiamake
Lanoway, Dryden
Baig, Shehroze
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Reliable Tire Recycling (RTR) tasked Team 2 to develop a recycling method for a synthetic fibre by-product produced by their tire recycling process. This by-product is made from a heterogenous mixture of short fibres such as polyester and nylon and contains significant amounts of impurities like dirt and crumb rubber. RTR expressed interest in using the by-product to create a new parking curb that would supersede their current model. They requested that the new design be light enough for a single person to carry, be able to withstand all-year Winnipeg weather, and can hold up during interactions with vehicles (i.e., collisions, rollovers, etc.). Team 2 proposed a new parking curb that incorporates the fibre by-product into RTR’s existing rubber mixture, paired with a redesigned form that meets the specified design objectives. The redesign includes underside cavities as well as reduced length for weight and material reduction. The proposed curb would be composed of 22% fibre by-product by mass, which was mixed directly into the rest of the ingredients (70% crumb rubber, 7.5% hydraulic binder, 0.5% water) to create test specimens for material evaluation. The mixture was formed by compressing it with 1700 psi of pressure and baking it at 100 °C. Other compositions were tested as well, including a control composition, 5% fibre by-product, 12% fibre by-product, RTR’s existing curb and two existing market options. The density of each test specimen was calculated first, and that density was used to determine the weight a proposed curb would be if it was made using each composition. All compositions containing fibre would result in a curb weight under the 35 lb design objective. The test specimens were evaluated by uniaxially compressing them according to ASTM standards. This test showed that the addition of fibre by-product, as well as applying higher pressure in the material creation process made the material deform less under load. All specimens containing fibre deformed less than 50% under the design load of 100 psi, passing the design objective. All specimens were then subjected to thermal testing, where they were exposed to extreme hot and cold temperatures (+75 °C and -80 °C respectively). After exposure, each was inspected for deformation and then hit with a metal rod at 21.7 km/hr to evaluate how it responded to impact force. All specimens passed, as none degraded noticeably post temperature exposure and all withstood the impact. A digital curb was then constructed using the 22% fibre by-product mixture, which was then subjected to 100 psi of pressure on the top face. The digital curb deformed a maximum of 8%, passing the deformation design objective. After analyzing the test results Team 2 recommended that RTR make several changes to their current mode of production. It was recommended that RTR increase the pressure used to manufacture curbs and begin introducing the fibre by-product into their curb mixture, starting with 22% replacement of crumb rubber for increased strength and reduced waste to landfill. It was also recommended that RTR adopt a curb design similar to the one proposed by Team 2 for weight, material, and cost savings.
Biosystems Engineering