What are composite fabrics?

Composite fabrics refer to multiple layers of fabrics bonded together, or fabrics combined with polymers or other materials to form a complex with multiple functions. In recent years, research on composite fabrics has mainly focused on waterproofing, moisture permeability, conductivity, antistatic, electromagnetic wave protection, photocatalysis, temperature regulation properties, and composite materials using composite fabrics as reinforcement bases.

According to the materials composited with fabrics, composite fabrics can be divided into three categories: fabric/fabric composite, polymer/fabric composite, and metal/fabric composite. From a technological perspective, fabric composites can be achieved through fabric structure design, fabric lamination technology, coating technology, or through electroless plating, vacuum plating, and sputtering technology.

　1. Design of fabric structure

The composite of woven fabrics and knitted fabrics can be realized through the reasonable design of fabric structure. For example, woven knitted composite fabrics made of glass fiber as warp and weft yarns and high-strength polyester as knitting yarn can be used in the field of industrial reinforcement materials. For example, polyethylene glycol is used as the dispersion medium and nano-silica is used as the dispersed phase particle to produce a shear thickening liquid (STF), and a liquid composite process is used to prepare a composite fabric of STF/aramid fiber/ultra-high molecular weight polyethylene fiber. It can be used for the preparation of efficient, lightweight and comfortable bulletproof materials.

　2. Lamination technology

The direct composite method of fabric is the composite of fabric and fabric. The typical structure is composed of outer fabric, adhesive, middle film layer, adhesive, and inner fabric, which is often called laminated fabric. The material of the fabric layer can be natural fibers or chemical fibers such as polyester and nylon. The fabric used can be woven fabric, knitted fabric, or non-woven fabric. The middle layer is usually a film or fiber mesh structure. The raw materials of the membrane material mainly include PVC, PU and PTFE.

　3. Coating technology

Textile coating usually refers to coating polymer compounds evenly on the surface of the fabric to form one or more layers of films on the surface of the fabric. It can not only improve the appearance and style of the fabric, but also increase the functionality of the fabric and make the fabric have Special functions such as waterproof, water pressure resistant, breathable and moisture-permeable, flame retardant, anti-fouling, and light-blocking and reflective.

Using coating technology, conductive metal or metal oxide particles can also be added to the coating slurry to form a conductive coating on the surface of the fabric, so that the fabric can obtain properties such as conductivity, electromagnetic shielding, thermal conductivity, photocatalytic degradation, and wave absorption. , its main metals or metal oxides include silver, copper, iron oxides, titanium dioxide, etc. During the coating process, metal materials need to be refined into nanoparticles to ensureForm a uniform and strong conductive metal film on the surface of the fabric.

　4. Aggregation method

Based on the performance requirements of the fabric, composite fabrics with certain special functions can be prepared by combining some polymer materials with fabrics. Commonly used polymer materials include polyaniline, polypyrrole, polythiophene, polyurethane, etc. For example, a simple and easy liquid phase in-situ polymerization method is used, using polyester fabric and nylon fabric as the matrix, and aniline and pyrrole monomers are polymerized in situ on the surface of the fabric to form polyaniline and polypyrrole conductive layers, which can produce good flexibility. There are also conductive fabrics with better conductivity.

　5. Electroless plating technology

Blending or interweaving metal fibers with ordinary textile fibers can be used to prepare metal composite fabrics. This type of composite fabric can also be obtained through electroless plating technology, which uses chemical reactions to reduce metals into atoms or molecules and deposit them on the surface of fibers or yarns. According to the different plating metals, it is divided into electroless nickel plating, electroless copper plating, electroless cobalt plating, electroless tin plating, electroless silver plating, platinum and other precious metal plating.

　6. Vacuum plating and sputtering technology

Vacuum plated fabric is a metallized composite fabric obtained by depositing metal on the surface of the fabric after forming vapor under vacuum conditions. For example, iron oxide/quartz fiber composite fabrics made by electron beam evaporation technology can be used in broadband wave-transmitting materials.

Sputtering fabric is a composite fabric made by using high voltage of anode and cathode electrodes under ultra-vacuum conditions to accelerate inert gas ions to hit the metal target, and the released metal atoms or molecules are attached to the fabric. If this technology is used to prepare thin and light glass fiber/silver composite fabrics, it can be used as radar absorbing material. However, due to the high cost of sputtering processing, it can only be produced in small quantities, which limits its promotion and application to a certain extent.