crease recovery

Crease Cotton cellulose chain contains -OH groups in both Amorphous and Crystalline region. There are Hydrogen Bonds between the-OH groups of the molecular chains. When a load is applied on to the cotton fabrics, the cellulosic chain in the fiber bends and this bending remains permanent since the cellulosic chains are In-elastic This bending of the cellulose chains of the fiber under the application of load causes the formation of crease.  In another theory, the Hydrogen bonds formed between the -OH group of adjacent cellulose chain in the crystalline region are broken (being a weak bond of force) when a cotton fabric is folded and pressed. The breakage of the Hydrogen bonds in the crystalline region and the formation of New hydrogen bonds in the amorphous region causes the formation of creases  METHOD TO PREVENT CREASE FORMATION

The method of minimizing the formation of creases involves the reaction of the -OH groups of adjacent cellulose macro-molecule, with some cross linking agents. The introduction of cross-links imparts dimensional stability and elasticity to the fibrous material and make it crease resistant and crease recoverable.

The most commonly used cress linking agents are nothing but Resins. The resins react with the -OH groups of cellulose forming Cross links which is durable and hence increases the Crease Recovery there by Dimensional Stability of the fabric. Resin finishing gives some advantages and some disadvantages to the fibrous material ADVANTAGES  1 It improves the Crease Resistance and Crease  2. It reduces the shrinkage of the fabric during 3. It imparts a smooth and quick drying property Recovery property laundering  4 It improves Resilience, Handle and Drapping qualities s. 5 It improves the weight and Dimensional stability. 6 It increases the strength of rayon’s in both wet and dry state. 7 It gives resistance to degradation by light and 8 It improves the fastness to Light and Washing of many  9. It prevents the Inter molecular Slippage in, the fibre core 10  It becomes partially water proof and Rot-proof. Disadvantages  1 it decreases the Tensile strength and Tear strength. 2 it  decreases the Abrasion resistance 3 It gives unwanted Harsh and Stiff feel 4 It turns the fabric yellow after chlorine bleaching. Incorporation of proper softener and catalyst in the ad bath can reduce the less in the above mentioned properties of the fabric.