History
Different Properties and Uses of Cotton Fiber
Effect of HeatCotton is excellently resistant to degradation by heat. It begins to turn yellow after several hours at 120 degrees Celsius (248 degrees Fahrenheit) and decomposes markedly at 150 degrees Celsius (302 degrees Fahrenheit). As a result of oxidation, cotton is severely damaged after a few minutes at 240 degrees Celsius (464 degrees Fahrenheit). Cotton burns readily in the air.
Effect of Age When stored carefully, cotton shows only a slight loss of strength. It can be kept in the warehouse for long periods without showing any significant deterioration. After fifty years of storage, cotton may differ only slightly from fiber a year or two old. Ancient samples of cotton fabric taken from tombs over 500 years old had 80 percent of the new material's strength.
Effect of SunlightThere is a gradual loss of strength when cotton is exposed to sunlight, and the fiber turns yellow. The degradation of cotton by oxidization when heated is promoted and encouraged by sunlight. It is particularly severe at high temperatures and in the presence of moisture. Much of the damage is caused by ultraviolet light and by the shorter waves of visible light. Under certain conditions, the effects of weathering in direct sunlight can be severe. The cotton can be protected to some degree by using suitable dyes.
Uses of Cotton FiberIn cotton, nature has given us an all-round utility fiber that is second to none. Cotton fabrics combine remarkable durability with attractive wearing qualities. Cotton fabrics have a pleasant feel or “handle”. They are cool in hot weather.
Cotton is inherently more substantial and stronger when wet than when dry. This property, allied with cotton’s stability in water and alkaline solutions, endows cotton garments with a long, useful life. Cotton can withstand repeated washings and is, therefore, ideal for household goods and garments that can be laundered repeatedly. Heavily soiled garments can be rubbed vigorously without being damaged.
Cotton plant with flower
The cotton fiber itself is dimensionally stable. Although a made-up cotton garment may shrink to some extent due to the tensions introduced by spinning and weaving, the fiber itself does not contribute significantly to any shrinkage.
This so-called “relaxation shrinkage”, caused by the easing of strains set up during spinning and weaving, can be overcome by a treatment called compression shrinkage. Rigmel and Sanforized shrunk cotton fabrics are compression shrunk in this way; they are dimensionally stable and will neither stretch nor shrink more than 1 percent in either direction.
Rigmel method: The fabric is subjected to high pressure and steam, causing the fibers to relax and contract to their maximum extent. This method can be used on a variety of cotton fabrics.
Sanforized method: The fabric is treated with a chemical process to stabilize the cotton fibers. This prevents them from shrinking when exposed to water. It is often used for high-quality cotton garments.
In essence, both Rigmel and Sanforized processes are designed to pre-shrink cotton fabrics, ensuring that they retain their shape and size even after multiple washes.
This so-called “relaxation shrinkage”, caused by the easing of strains set up during spinning and weaving, can be overcome by a treatment called compression shrinkage. Rigmel and Sanforized shrunk cotton fabrics are compression shrunk in this way; they are dimensionally stable and will neither stretch nor shrink more than 1 percent in either direction.
Rigmel method: The fabric is subjected to high pressure and steam, causing the fibers to relax and contract to their maximum extent. This method can be used on a variety of cotton fabrics.
Sanforized method: The fabric is treated with a chemical process to stabilize the cotton fibers. This prevents them from shrinking when exposed to water. It is often used for high-quality cotton garments.
In essence, both Rigmel and Sanforized processes are designed to pre-shrink cotton fabrics, ensuring that they retain their shape and size even after multiple washes.
