The production of composite fabrics involves various composite processes. Six internationally popular processes include hot melt adhesive powder coating, hot melt adhesive paste coating, hot melt adhesive powder sprinkling, hot melt adhesive double-dot coating, polyurethane spray coating, and polyurethane roller coating.
In addition, PTFE laminated composite fabrics are made by laminating 100% pure polyester thickened high-strength nonwoven fabric with a polytetrafluoroethylene (PTFE) microporous film using special technology and equipment. These fabrics possess multiple functions, including virus blocking, antistatic properties, blood penetration prevention, waterproofing, moisture permeability, windproofing, and warmth retention.
The production process typically includes lamination, bonding, and conditioning. During lamination, the reverse side of the fabric is first laminated, bonded using chemical materials, and then conditioning is performed. Currently, the most commonly used adhesives in the apparel industry are polyurethane hot melt adhesives (TPU or PUR hot melt adhesives), which have advantages such as high bonding strength, good softness and elasticity, heat and water resistance, and no formaldehyde release. Some manufacturers may use oil-based adhesives (solvent-based adhesives) to reduce costs, but the residual volatile organic solvents may pose potential health hazards. The curing time and temperature/humidity directly affect the quality of the finished product; the longer the curing time, the better the bonding strength of the fabric and the degree of adhesive fusion. Generally, domestic adhesives require three days, while imported adhesives require five days or longer.
Lamination processes significantly alter the final properties of the fabric. For example, after lamination, the thickness and stiffness of the fabric usually increase; the elongation and breaking strength of knitted fabrics may decrease, while the static tensile properties of woven fabrics may improve; simultaneously, the flame retardant properties of laminated fabrics may be affected by the interlayer material. These performance changes can be controlled by adjusting factors such as the structure of the single-layer fabric and the parameters of the lamination process.