Research On Vacuum Assisted Resin Infusion Molding And Device Development

As a kind of thermosetting resin matrix composite craft, vacuum assisted resin infusion molding has been widely used due to its advantages of simple craft, low cost high flexibility, etc. This dissertation mainly focused on the vacuum assisted resin infusion molding and did research into the craft for maching thin parts and thick parts, and then developed the enclosed type of mixing device. Based on the previous research, a set of device with VARI was finally completed. The specific contents of this paper are as follows:(1) Taking machining thin parts as research object, this paper studied the influence of injection port number, injection location and sequential starting-ending which in the process of VARIM on filling time and defect formation by made a comparison with experiments and simulations. Based on these research, this paper gave an analysis of the cause of defect formation during filling the parts and advanced some of improvement and optimization techniques that can avoid defects and shorten time.(2) Taking machining thick parts as research object, this paper studied the influence of injection port number and sequential starting-ending which in the process of VARIM on filling time, defect formation and mechanical properties by made a comparison with experiments and simulations. Based on these research, this paper gave an analysis of the cause of defect formation during machining thick parts and advanced some of improvement and optimization techniques on filling process.(3) A set of enclosed type mixing device for vacuum assisted resin infusion molding was developed. This paper made an optimal selection on static mixer which was the core component of mixing device and blade quantity by using numerical simulation after completed the mixing process and carried out digital image processing to those pictures of mixing materials took by the stable light photo device. Then verified how the blade quantity of the mixer effected the mixing performance by experimental verification.(4) A complete set of vacuum assisted resin infusion molding device was achieved. Since the craft of vacuum assisted resin infusion molding was made of four steps (preheating, mixing, infusing and curing), the device was build up with four systems:constant-temperature workbench system, closed mixing system, vacuum power system and forming control system. Finally, the automatic control of filling process of this device was achieved by the photoelectric sensors monitoring the resin front position which based on refraction-reflection principle of transmission light and the PLC.