Compressibility of Composite Materials Reinforced with Nonwoven Needlepunch Cloth Made of Polypropylene Fibers of Increased Linear Density

The compressibility of composite materials prepared by impregnation with an aqueous polyurethane dispersion of cloth made of polypropylene fibers of linear density 0.66 tex was studied. An approach to the determination of the dependence of the compressibility of the composite materials on the degree of impregnation of the cloth and the pressure on the materials was proposed. The optimal degree of impregnation of the cloth above which a substantial drop of the compressibility was observed was established. The compressibility decreased if bridges of polyurethane particles formed between the fibers. The orientation of the cloth fibers, which depended on the linear density of the fibers during punching of the fabric, was another structural factor determining the compressibility of the composite materials.