Study On Wearable Nylon6Composite Material For Supporting Roller

Supporting roller is one of the key components of belt conveyer. Aiming at overcoming the shortcomings,such as easy rust, low wear resistance, heavy-weight, easy to stick material, poor toughness and low strength of the steel, ceramic and plastic rollers on the current market, the composites for supporting roller based on high-strength, wearable and self-lubricating nylon6as matrix, glass fiber (GF) as reinforced materials, talc, carbon black and graphite as modifier, are prepared. The formulations, properties and wear mechanism of the wearable nylon6composite are investigated. The main works are as listed below:First, the composites of PA6/GF were prepared by twin-screw extruder extrusion. The influences of GF content, proportion of low-viscosity PA6(LVPA6) and medium-viscosity PA6(MVPA6) on the mechanical properties, friction and wear behavior, process parameters and thermal stabilization were discussed. The results show that the tensile strength, flexural strength and notched impact strength of PA6/GF composites reaches the maximum value when the ratio of MVPA6/LVPA6is70:30. Meanwhile, the effect of GF content on the tribological properties of the composite was investigated.On the condition of the sliding speed of200r/min and loads of200N, it has been found that the friction coefficient of the PA6/GF composites reaches the minimum value when GF content is40wt.%; and GF-reinforced PA6composite with30wt.%of GF has the highest wear resistance and mainly shows the wear mechanism of adhesive wear.Secondly, PA6/GF/Talc composite with GF-reinforced PA6as matrix, talcum powder as fillers, was prepared. Effects of proportion and size (H1:200meshes; H2:1250meshes) of talcum powder on the mechanical properties, thermal stability and tribological properties of the composite as well as the wear mechanism were investigated. The results present that tensile strength, flexural strength and notched impact strength of the composites decrease slowly, the thermal properties are improved gradually with the increase of H1/H2(w/w); At the sliding speed of400r/min and load of200N, the composite obtains the minimum friction coefficient with the H1/H2of12/8; also, the modified material with H1/H2of15/5exhibits the optimal wear-resistant property; and the obtained product without talc shows wear failure phenomenon. The result of this study indicates that with the increase of H1content, the wear mechanism of the composites shifts from adhesion wear to particle wear.Finally, PA6/GF/Talc composites filled with carbon black were prepared, and the influences of carbon black content on the properties of the composites were discussed. The results show that it has the best tensile strength and flexural strength when the composite were filled with5wt.%carbon black;the notched impact strength reaches its maximum value when the addition amount of carbon black is3wt.%;the flow properties of the composites deteriorates and their thermal stability is enhanced with the increasing carbon black content. At the sliding speed of400r/min and load of200N, the friction coefficient of composite with H1/H2of15/5gradually increases with the increment of the content of carbon black, and the composite with the same H1/H2ratio has the highest wear resistance property and only shows a slight particle wear and adhesive wear when it was filled with7wt.%carbon black.