Simulation And Optimization Of Composite Molding Process Using High Viscosity Flame Retardant Resin

Composite has been widely applied in the field of aerospace, public transport and infrastructure, because of it’s small specific gravity, high strength, molding easiness, outstanding designability, maintenance costs. But the majority of the matrix of composite is polymer organic material, it generate a lot of dust, smoke and toxic gases when burned, so it has security risks.Therefore, the excellent flame retardant properties of the composite become the premise that it can be widely applied. The present flame-retardant methods of composite include the use of the reactive flame and the additive-type flame retardants. Taking into account the economic and flame-retardant effect, aluminum hydroxide (ATH) is selected as the flame-retardant filler. ATH will be decomposed into alumina and water, the alumina powder not only isolates the role of oxygen, but the change from water to the water vapor can absorb more heat. In addition, ATH is amphoteric hydroxides, which can neutralize the toxic smoke of acidic and alkaline substances. When adding the filler in the resin, the viscosity of resin becomes high, this results in the difficulty of the composite molding process.The viscosity of the Unsaturated Polyester Resin (UPR) adding aluminum hydroxide (ATH) was tested and analyzed at different temperature and various content of accelerator by Digital Viscosity Instrument. And simulate VARTM (Resin Transfer Molding) and RTM (Vacuum Assisted Resin Transfer Molding) process using a composite part. Experimental results show that:(1) The temperature plays a major role in the value of initial viscosity and the average viscosity. However, in the case of not adding the curing agent, the viscosity of the resin becomes high with time.(2) Based on a set interval, the influence of temperature to gel time is greater than the accelerator.(3) The permeability of glass fiber mat in each direction are substantially equal.The simulation results show that: (1) When the inlet is larger than the outlet, the filling time of VARTM process is almost equal to RTM process. So VARTM process is better in actual production, VARTM process can avoid the emergence of the dry spot.(2) When the inlet is smaller than the outlet, the filling time of VARTM Process is less than RTM. When the differences in the size of the inlet and outlet are greater, the differences the filling time will be greater.