Cushion Polyurethane Sandwich Composite Structures Strengthened by a Concave-Convex Fabric Panels

In order to improve the low velocity impact resistance, flexible PU foam composites (FPUC) with a sandwich structure are proposed. The interlayer is composed of a concave-convex fabric structure while the top/bottom layers are made of polyurethane foam (PU). The core is prepared as follows. Seven warp knitted spacer fabric types (WKSF) (WKSF.1-7) are laminated with different number of layers to form cuboids, which are fixed firmly between two layers of low melting point polyester (LMPET) fabrics via hot melting. The effects of spacer yarn density, spacer yarn inclination angle, combination of spacer fabrics, and number of lamination layers on the dynamic cushion performance are evaluated. With the impact energy being 16 J, FPUs demonstrate an energy absorption level that is 19 % and 39 % greater than PU and WKSF. Furthermore, ultra-high molecular weight polyethylene fabric can effectively enhance the surface strength. Finally, the results are computed via theoretical prediction formulae of dynamic buffer resistance is in conformity with the experimental test results.

Automated summary

This research proposes a flexible PU foam composite with a sandwich structure to improve low velocity impact resistance. The results show significant improvement in dynamic cushion performance through the design of the interlayer structure, and they are validated through experimental and theoretical calculations.