Preparation And Properties Of Of EVA Composite Material

Nowadays,Global rail transit field is rapidly developing in the field of rail transit.EMU undertakes high-speed and long-distance transport tasks.The noise level of the car becomes an important factor affecting the ride comfort.With the improvement of the operation speed of high-speed EMUs,Acoustic noise reduction has become one of the key and difficult issues in the design and manufacture of vehicles.The advantages and disadvantages of the sound insulation performance of the car body floor,a direct impact on the noise under the car to the car's spread.As one of the main components of sound insulation and noise reduction for high-speed EMU,sound insulation floor is designed to timely design sound insulation floor with better lightness and sound insulation performance,and structural improvement and structural improvement of EMU design for different speed grades can be achieved.The purpose of comfort.In this thesis,we choose EVA resin as the base material,melt blending with other resins to get the better performance alloy resin,then add the flame retardant and sound insulation filler to obtain the comprehensive performance of fire-retardant and sound-proofing EVA composite material.The following conclusion:1.Barium sulfate,iron powder and mica powder were be used as soundproof fillers to improve sound insulation.It is found that barium sulfate is the most suitable sound insulation filler for EVA system.When adding 300 units of barium sulfate,the tensile strength of EVA composite material is 6.1 MPa,the elongation at break is312%;it shows that the system gets good sound insulation performance while it's mechanical properties meet the requirements of use.EVA/TXT obtained by self-made TXT resin modified EVA has a glass transition peak at 15?,high damping tan?and EVA/TXT alloy with better dynamic mechanical properties.Under the premise that the total amount of resin is constant,the glass transition peak of EVA/TXT alloy gradually shifts to the right and tan?increases with the increasing amount of TXT resin.The EVA/TXT composites with better formulation were screened out when the formulation was EVA68,TXT resin 32,Barium sulphate300,WO4 4?HSt 4,1010 2.Performance,hardness 84A,density 1.81g/cm^-3,tensile strength 4.1MPa,elongation at break of 354%.2.Comparing the flame retardant performance of metal hydroxide,aluminum hypophosphite and intumescent flame retardant 5002 to EVA shows that the flame-retardant efficiency of intumescent flame intumescent flame retardant 5002 to EVA to EVA is the highest.50%added of 5002 makes the vertical burning reach level V-0,increasing the oxygen index to 45,and the flame retardant performance has been significantly improved.According to the further study of combustion behavior of EVA/TXT/retardant 5002,the heat release behavior of EVA with 30%of intumescent flame retardant dropped dramatically,the peak heat release rate reduced to 156kW/m^2,which is 21.8%of pure EVA/TXT.This system formed a dense expanded carbon layer,the inter surface of carbon layer is regular honeycomb expansion structure.The outer surface carbon layer is not only of good quality,but also bulging uplift into a spherical shape.This carbon layer structure effectively suppresses the volatilization of combustible gases and blocks the transfer of oxygen and heat,thereby achieving good flame retardant and smoke suppression effects.3.The influence of pressure and temperature on the mechanical properties and flame retardancy of EVA/TXT/retartdant/sound-proof filler composite was studied.It turns out that air holes can be found on the surface of the product without vacuum;However,if the air were pumped out in the barrel,the molded part would be denser and the surface of the product would be smoother.160?is the proper manufacturing temperature and higher temperature may cause intumescent flame retardant to partially dissolve,reducing the flame retardancy effect.A series of sound-proof floors were obtained by combining the sound-proof material manufactured and light-weight panels.If the thickness of the floor is constant,then the sound-proof ability increases as the thickness of the sound-proof material increases.When the sound-proof material is 6mm thick,the sound reduced by the material is 36.7dB?A?.However,considering the fact that rail-way products have light-weight requirements,a floor with 5mm sound-proof material is the optimum solution.If the density can match the purpose,a sound-proof effect of 35.0dB?A?can be reached.