Enhancement of mechanical and wear-resistant properties of polymer composites is important because they are widely used in tribological environments. The properties can be enhanced by reinforcement with particulates in the polymer matrix. Nylon is used in many engineering applications, and silica fume is used as a filler material in civil-oriented applications. In this paper, the properties of Nylon 66 reinforced with silica fume particulates are investigated. The reinforcement by silica fume at 5%, 10%, 15%, 20% and 25% weight fraction is considered. Nylon 66 and silica fume were compounded in a twin screw extruder and the test samples were produced in 60 ton L&T injection moulding machine. Heat distortion temperature (HDT), tensile, flexural, compression and impact strength tests were carried out in accordance with ASTM standards. The test results confirmed the improved mechanical and HDT properties of the Nylon 66-silica fume composites. Observations made using scanning electron microscopy revealed good physical adhesion and uniform dispersion of silica fumes in the Nylon 66.

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Selecting the right supplier can be one of the most critical decisions for manufacturing firms. Strategic issues often dictate whether a company thrives or fails. When making important decisions, certain people consider the importance of green-friendly criteria before selecting a supplier. Various companies prioritize green suppliers in their selection process. This work considers the grey method of choosing green suppliers by considering the excellence and weakness. In addition to the green suppliers, the allocation of orders is carried out. The green vendors are focused on utilizing grey, and the demand is assigned by utilizing linear discounts for multiple products and time periods. This work introduces an integrated model with multiple products and time periods for determining demand using green criteria. The outcome of this work is to assign orders to the best suppliers to increase total purchase value while reducing total purchase costs. Then, the method is depicted with a numerical model in a linear discount scenario. A sensitivity analysis was carried out. TVP and TCP differences in order quantity and optimum solution are illustrated in the sensitivity analysis. The numerical model is programmed and resolved by LINGO 18.

Nylon 66 is an engineering thermoplastic which has been found to be a suitable alternative material for metal parts in low and medium load bearing applications. Particulate filled polymer composites are preferred in this kind of tribological environment, because of their enhanced wear resistance properties. Fly ash and silica fume are industrial wastes which are now looked as potential fillers to enhance the material properties at low cost. Nylon 66 was reinforced with these filler materials at 15% weight fraction using a twin-screw extruder. The specimens were prepared using an injection molding machine of 60 ton capacity. The tests were carried out under dry sliding conditions in a pin-on-disc type friction and wear monitoring test rig. The tests were conducted at various sliding velocities of 2 m/s, 3 m/s and 4 m/s, at three different normal loads of 20 N, 40 N, 60 N and at a constant sliding distance of 5000 m. SEM observations were made to study the wear mechanisms in the composites. Both types of composites showed enhanced wear properties compared to neat Nylon but fly ash filled Nylon composites were superior to silica fumed filled Nylon composites.

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