Analysis Of Resin System And Its Influence On Process Of Vacuum Assisted Resin Transfer Molding

Compared with the traditional metal material, composite materials have incomparableadvantage in manufacturing wind blade, auto parts and aviation and so on due to its lowweight and high strength. In recent years, there are many processes in preparing compositematerials, among them vacuum assisted resin transfer molding (VARTM) process is low costmanufacturing technology to produce advanced composite materials. This paper mainlyfocuses on optimizing the VARTM process.In this article, the R2711-A/2711-BF epoxy resin system was characterized to study thechemical rheology by rheological instruments by dynamic heating method and isothermaltemperature method.It was found that the system is applicable in low and mediumtemperature curing. The relationship was established between the viscosity and curing degreeby WLF equation. This system gels after the cure degree is0.52, then it went into diffusioncontrolled stage, post curing must be considered in VARTM process. Second platform wasfound in loss modulus which may correlates with the principle of curing system. As thetemperature increases, glass transition point becomes more and more not obvious untilvanishing. The apparent activation energy was calculated to be54.501KJ/mol according toArrhenius logarithmic method.Two different curing models was analyzed in R2711-A/2711-BF system,nth order modeland autocatalytic model. The apparent activation energy was52.991KJ/mol, which isconsistent with the chemical rheological result; the temperature range was55-75oC2hr+130oC1hr for VARTM process. One dimensional heat transfer model was established to studyheat transfer of VARTM process, it was found that temperature distribution correlates wellwith experiment by solving the equation with autocatalytic model.Mechanical properties of the composite samples prepared by VARTM process was testedand the results show that the glass transition temperature of epoxy resin system increased by15oC after reinforcing glass fiber, in addition, they confirmed that70oC2hr+130oC1hr curingprocess for VARTM is best,under which the sample has best bending performance.