The Effect Of Carbon Black And CZ On Mechanical And Dry Friction Properties Of EPDM Rubber

The main drive system is one of the core components of the TMB.It also provides all the thrust of the propulsion system while providing the rotary torque of the cutter head.Because the reliability of the main drive system is very high,the main drive seal is the key to ensure its normal operation.In the course of the main driving operation,although the oil is injected with certain pressure,the failure process of the main driving system is accelerated by the dry friction of the rubber seal because of the mechanical installation error,partial or partial presence of sand,resulting in the absence of oil and the state of the oil.EPDM has been gradually applied to the main driving seal of TMB because of its excellent wear resistance,heat resistance,corrosion resistance and aging resistance.So far,little attention has been paid to the effect of carbon black and CZ fraction on the mechanical and dry friction properties of EPDM.Therefore,this paper takes EPDM formula as the research object,analyzes the mixing and vulcanization technology.Through the research of mechanical properties and tribological properties,the optimum formula of CZ and carbon black content of EPDM is found to meet the requirements of the main driving seal of the TMB.Through the study,the following conclusions are obtained:First of all,CZ accelerator and sulfur were used to investigate the effect of CZ fraction on the mechanical and Tribological Properties of EPDM rubber.The results show that with the increase of the number of CZ,the tensile strength,hardness and wear resistance of EPDM were increased first and then decreased,and the maximum value was obtained when the number of CZ parts was 0.5 parts.After that,carbon black is an important material in the EPDM reinforcement system.The change of carbon black fraction can adjust the hardness and mechanical properties of EPDM rubber.The results show that with the increase of carbon black fraction,the hardness and tensile strength of EPDM increased,and the elongation at break decreased.Under high load,with the increase of carbon black fraction,the wear resistance of EPDM rubber increased,and the surface temperature of grinding marks increased.Under low load,the wear resistance of EPDM increased with the increase of carbon black fraction.Finally,the bonding force of molecular bonds is relatively weak at high temperature,which is likely to cause elastic and mechanical properties of seals.In order to better study the properties of rubber at different temperatures,the change of the hardness of rubber at different temperatures was studied,and the change of hardness in the process of heating and cooling was considered.The EPDM is still in the rubber state at the 190 degree temperature during the heating process,but it is in the viscous flow state at 210 temperature,and can not work normally.Through the above study,the basic formula of EPDM for the main driving seal is obtained: EPDM 100phr;sulfur 1.5phr;CZ 0.5phr;Zinc Oxide 5phr;stearic acid 1phr;carbon black 70phr;antiaging agent 0.5phr;naphthenic oil 15 phr.