Research On The Process And Properties For Foam Core Sandwich With Thermal Expansion Molding

Base on conventional manufacture methods, a new manufacturing for foam core sandwich structure composites was studied in this article. Conventional curing pressure was provided by external equipments, such as autoclave, vacuum bag and so on. In this work, the foam core sandwich structure composite were manufactured within a mould with the pressure generated by the thermal expansion of foam and the stiff mould. As no additional facility is needed to provide pressure, the cost of composite process will be reduced. The pressure was analyzed and measured when the manufacture of foam core was controlled. In addition, flexural strength, peel strength and impact resistance of this structure also be tested.During the section of design for feasibility of thermal expansion molding, the expansion property of EPS foam core make enough pressure at the appropriate time possible. According to the requirement of the process, resin curing system was selected according to viscosity. Feasibility was approved by the theoretic design.The specimens were product via the thermal expansion molding, with the facility self designed. Therefore this new method was available. The pressure which generated inside the mold was affected obviously when changed the process of foam core. During the process of foam core, the less time and lower temperature, the higher pressure could generate.The mechanical properties testing of foam core shown that flexural strength will increased while higher pressure generated by the foam core. But the rule was not available at the high foam core density with high pressure. It was also shown that foam core process had a little affection on the peel strength. But the peel strength enhanced while the face resin content increased. Due to the special structure of foam core in the thermal expansion molding process, the sandwiches have a higher impact resistance than the foam core sandwich with general foam core structure.