Research On PPS Sheet Viscous Warm Pressure Forming Process

According to the mechanical properties of polyphenylene sulfide(PPS)resin under warm conditions,combined with the thermoforming characteristics of viscous media,the thermoforming of PPS sheet was studied.Under warm conditions of tensile experiments and the warm viscous pressure bulging experiments were conducted to analyze the effects of forming temperature and viscous medium on the formability and forming quality of PPS sheet.In addition,proposed in the viscous medium filled with a certain mass fraction of magnesium powder,improve the warm forming process of viscous medium thermal conductivity,optimization of viscous medium warm forming process.Firstly,the tensile experiments under different temperature conditions,the mechanical properties such as the stress-strain curve and the sectional elongation of the PPS sheet under warm conditions were obtained.Through the tensile experiments under different speed conditions,the influence of tensile speed on the mechanical properties of PPS sheet was obtained,which provided an important basis for the selection of process parameters of PPS sheet warm forming.Secondly,the influence of forming temperature and viscous medium loading speed on the ultimate bulging height,profile curve and wall thickness distribution of PPS sheet were analyzed by means of the warm viscous pressure bulging experiment under different temperature and speed conditions.Through the finite element analysis of the forming process,the stress and strain in the process of thermal deformation of viscous medium of PPS sheet and the change of the velocity field of viscous medium were obtained.Finally,in order to improve the thermal conductivity of viscous medium during thermoforming,a method of adding magnesium powder into the viscous medium.Through the experiment determine the setting speed of magnesium powder in viscous medium and the influence on the compressibility of viscous medium.And the influence of magnesium powder with different mass fraction on the thermal conductivity of viscous medium.Through the warm viscous pressure bulging experiment filled with magnesium powder,the feasibility of filling magnesium powder for increasing the thermal conductivity of viscous medium and improving the thermoforming efficiency of viscous medium was verified.