Nonwoven performance path
First, mixed with high shrinkage fiber
The high-shrinkage fibers, such as polyvinyl chloride fibers, are mixed into the web, and the density of the needle-punched nonwoven material can be increased by treatment with hot air, steam or hot water after needle punching.
According to the product density requirements, the content of high shrinkage fibers in the web can vary greatly. For example, the content of high shrinkage fiber in the fiber web is 80%, and the shrinkage rate after heat treatment can reach 50%.
The method can improve the density of the needle-punched nonwoven material, reduce the surface acupuncture marks, has good multiple bending resistance, and has good delamination resistance, and is suitable for use as a synthetic leather base cloth. However, since the high shrinkage fiber loses most of its strength due to structural changes during heat treatment, the strength and dimensional stability of the product are insufficient.
Second, mixed with heat bonding fibers
The heat-bonded fiber is mixed into the fiber web, and after hot-rolling after needle punching, the strength and dimensional stability of the needle-punched nonwoven material can be improved, but the hardness of the nonwoven material is increased, and the resistance to multiple bending is lowered.
This method is generally not used independently as an enhancement to the needled nonwoven material and can only be used to provide additional reinforcement to the needled nonwoven material on which the base fabric is laid.
The heat-bonded fiber is not mixed into the fiber web, and after hot-rolling after needle punching, the fiber hairiness can be flattened and bonded to improve the surface quality of the needle-punched nonwoven material, and the coating amount can be reduced when used as a coating base cloth. .
Third, laying the base fabric
Laying a light-weight base fabric can greatly improve the initial elastic modulus of the nonwoven material, but it does little to improve the breaking strength. Laying high-strength heavy-duty base fabrics can greatly increase the breaking strength of nonwoven materials, but attention must be paid to the damage of the base fabric.
Studies have shown that when the depth of the needle is 13mm and the density of the needle is 200 thorns/cm2, the single-edge hook needles are arranged in the longitudinal position. After the needle punching, the longitudinal strength of the base fabric remains 90%, and the lateral strength remains 28%; the single-edge hook needle Arranged in the lateral position, the longitudinal strength of the base fabric after acupuncture remains 10%, and the lateral strength remains 90%. Reasonable setting of the arrangement angle of the lancet hooks can balance the longitudinal and lateral residual strength of the base fabric after acupuncture. If the angle between the edge of the single-edge hook and the hook is 40°, the longitudinal and lateral strength of the base fabric after the needle punching will remain about 50%.
The effect of different structural needles and their arrangement angle on the latitude and longitude of the woven base fabric.