Global Wetlaid Nonwoven Industry Growth and Trends Forecast to 2032

Definition

Wetlaid Nonwoven is a paper-like nonwoven fabric manufactured using a wet-laid process. Wet-laid webs are short fibers made from cellulose, polyester, glass, polyolefin, polyamide, viscose, pulp, polyvinyl alcohol and other materials dispersed in water to form a fiber slurry to obtain a certain composition, a certain viscosity and a A solution with good spinnability is called spinning dope, which can also be obtained directly from homogeneous solution polymerization. The spinning stock solution is pumped and continuously deposited on the inclined forming net, measured by the metering pump, and then enters the spinneret through the candle-shaped filter and connecting pipe. The thin stream of the raw solution squeezed out from the spinneret enters the coagulation bath. The solvent in the flow diffuses to the coagulation bath, and the coagulant penetrates into the thin stream, so that the original liquid stream reaches a critical concentration and precipitates in the coagulation bath to form fibers. Once the web is formed, various bonding methods are used to strengthen the fabric and hold the fibers together. These bonding methods may include mechanical agitation, needling, chemical bonding, or thermal bonding. The choice of bonding method depends on factors such as the desired properties of the final fabric and the intended application. The wet-laid process produces highly uniform fiber webs, high-precision weight and thickness, defined pore sizes and high porosity. The wet spinning speed (referring to the speed of the first godet for winding up the nascent fiber) is much lower than the melt spinning speed because it is limited by the double diffusion speed of the solvent and coagulant and the fluid resistance of the coagulation bath. The ratio of the linear speed of the first godet to the extrusion speed of the spinning solution is called the spinneret draw ratio. The wet spinning draw ratio is generally negative, zero, or a very small positive value in order to improve the stability of the forming process.