Flocking is a method to apply very short (1/10″ to 1/4″) fibers called flock to a substrate, such as fabric, foam, or film, coated with an adhesive. Flocking is an inexpensive method of producing an imitation extra-yarn fabric, flocked in a design, or a pile-like fabric where the flock has an overall pattern. Examples of end use of flocked fabrics for home furnishings include carpeting, upholstery fabrics, blankets, bedspreads, wall coverings, and window coverings. For clothing, flocked fabrics are used for shoes, hats, and apparel fabrics. Industrial uses include automotive fabrics, conveyor belts, air filters, books, and toys.
Application
The flock is applied to the fabric using a mechanical or electrostatic process. Depending on the process and fibers used, the effect may be a velvety or suede-like appearance.
Materials
Natural or synthetic fibers such as cotton, rayon, nylon, and polyester can be used depending on the particular end use. There is an advantage to using first-quality filament synthetic materials, because the flock can be cut square and in uniform lengths. Cotton is the least expensive and the softest but does not have good abrasion resistance. Rayon has the advantage of being low cost and uniform, but also has low abrasion resistance. Nylon has the best abrasion resistance. Present-day adhesives, such as aqueous acrylic, polyester, and nylon, have excellent bond and usually have the same flexibility and wear resistance as the substrate. The high-quality adhesives have excellent fastness to laundering, dry cleaning, or both, but it is important that testing is conducted to ensure that the cleaning method listed on the label is accurate.
Processes
After the flock is cut, it is then cleaned. The fibers and the substrate are dyed if they are to be colored. The adhesive is applied to the substrate in the desired design. The flock is then prepared depending on what method will be used to apply the flock to the adhesive. In the mechanical process, a simpler and less-expensive means of flocking, the fibers are placed in a hopper and sifted onto the substrate where beater bars vibrate the flock. The vibration helps the fibers become erect on the adhesive. The fibers randomly adhere to the substrate at different depths forming an irregular surface. Shedding occurs because not all the fibers adhere to the adhesive.
Electrostatic Process
In the electrostatic process the fibers are chemically treated to allow the fibers to receive an electrical charge. The moisture content is specified. Again the flock fibers are placed in a hopper where they are given an electric charge. A grounded electrode plate under the substrate orients the fibers in an upright position when they imbed into the adhesive. Electrostatic flocking is more expensive and slower, but the flock is more uniform and denser. It is also possible to flock both sides of the fabric. Although there is a difference in the two processes, most consumers are unable to tell what method was used on the flocked fabric.
Bibliography
Carty, Peter, and Michael S. Byrne. The Chemical and Mechanical Finishing of Textile Materials. 2nd ed. Newcastle upon Tyne: Newcastle upon Tyne Polytechnic Products, 1987.
Slade, Philip E. Handbook of Fiber Finish Technology. New York: Marcel Dekker, 1998.
