● The selection of different types of foam cores

(1)  Price: the price of PU, PVC and PMI are obviously different.

(2)  Mechanical properties: PMI has the better mechanical properties than PU and PVC that can satisfy the structural requirements which under the low density. The realization of lightweight, reduce the energy consumption of finalproduct in working status and increase the payload.

(3)  Processing properties: by the use of PMI’s high thermal resistance, technologist can shorten the cure time and increase the cure temperature, thus enhancing the equipment’s service efficiency and reducing the process cost.

(4)  Other properties: PMI also has the excellent dielectric property, low aluminum equivalency and outstanding anti-fatigue performance which can be use as the function materials.

● The selection between PMI and Honeycomb

(1)  Price: Generally, the price of honeycomb is lower than PMI, but in some industries with high performance requirements for cores, such as aerospace, the price of high-grade honeycomb is higher than PMI.

(2)  Mechanical properties: Honeycomb is anisotropic material, and in height direction, honeycomb undoubtedly has high mechanical properties. For PMI, its isotropy endows it has high and same mechanical properties in every direction. So, the designers don’t need to consider the direction of Honeycomb, which gives them a great deal of freedom and convenience.

(3) Processing properties: Honeycomb processing requires exclusive equipment. It also requires the labor & time consuming splicing and secondary bonding, and be injected with a great number ofsealants at the meantime. In addition, its large opening structure and anisotropy do not match the“Liquid Shaping”,“Curing outside the Autoclave” and“low cost rapid manufacturing” megatrends of composite. The processing of PMI allows the common CNC tools, and because of its rigid closed cell structure, it could be processed into lots of tiny structures and complex geometry without the sealants and secondary bonding.