Drying Processes of Textile Industry

Textile drying is one of the finishing processes, which removes the water and moisture from the fabrics (accumulated while its manufacturing) through evaporative heating. As evaporative heating is very costly, initially mechanical methods are applied to remove as much as moisture from the fabric as possible. After that, heated dryers are used to evaporate the remaining water from the fabric. Mechanical methods include centrifugal extraction of water and continuous methods applying vacuum suction rolls. After mechanical extraction, various types of dryers are used to dry the textile which are categorized as thermal processes. The thermal processes transfer heat by convection; infrared radiation; direct contact; or radio-frequency.

Drying can be applied to loose fibers, yarns, or fabrics. When drying fibers, centrifugal extraction is done to reduce the water in loose fibers before evaporative drying is applied. The evaporation dryers consist of many chambers and fibers pass from the hottest to the cooler chambers. Fiber is carried through a conveyor belt or on the surface of a series of “suction drums”. Yarn packages are dried by two methods - rapid (forced) air drying and the radio frequency drying. In forced air dryers, hot air circulation is followed by conditioning. Radio frequency dryers operate on the conveyor principle. Fabrics are dried with various types of dryers like stenters, cylinder dryers, drying conveyors etc. The relaxed fabric is conveyed through a chamber while festooned in loops. The fabric travels through the chamber, passing over a series of hot cylinders. It is very important to dry textile without over drying otherwise the fabric may get a harsh hand.