FGF Final Ppt Resin Finish

RESIN FINISHING AND WRINKLE-FREE FINISHES

Presented By:

Anurodh KumarRoll No.- 03Krishna MishraRoll No.- 07Raghavee GoelRoll No.- 15Shivangi KejriwalRoll No.- 21

INTRODUCTIONCellulose fibres are known for their comfort during wear and various other favourable properties.Resins are used for various wet finishes basically on cellulose and cellulosic blends Resin based finishes create cross linking that increases intermolecular rigidity.The resin finishes had been mainly been developed for the basic problems of crease formations on cellulosic fibers, thus these finishes came to be known as Anti crease or Anti crush or Crease Resistant or Crease Recovery finish ,easy care finish or Resin finish since resins are used for these finish.

OBJECTIVESMinimize shrinkageWeight of fabricAppearanceDimensional stability

WHAT ARE RESINS?Resins are the chemical group applied as wet finishes and used in many of the finishes.There are several types of resins, but most belong to the urea formaldehyde or related groups of organic compounds. The formaldehyde components have been suspected of being carcinogenic (cancer causing) materials. Another group of resins, used less extensively due to relatively high cost and limited effectiveness, are the dimethyl urea glyoxalin compounds which are non-formaldehyde producing.

DEPOSITION TYPE RESINSThese resins form a surface coating on the applied substrate (fabric).No reaction between fibers and the resin molecules.These type of resins give stiffness to the fabric and some extent of crease recovery, which is lower than cross-linking resins. If cured these resins show behavior similar to cross-linking type of resins.

CROSS LINKING TYPE RESINSThese resins chemically react with substrate molecules and form intermolecular cross-links.These are much durable and better than deposition type.They are also known as N-Methylol compounds as methylol groups are attached to the nitrogen and are also called pre-condensates.TYPES

APPLICATION TECHNIQUES

FOR DEPOSITION TYPE OF RESINSDeposition type of finishes are applied in soluble form on the surface of the cotton fabric using padding mangles with an acid catalyst and dried.Direct coating is also used for surface application of such resins. In the direct coating process the resin is spread directly on the fabric by means of a doctor knife or a cylinder.Some resins of this category are as follows:-Phenol Formaldehyde resinsAlkyd resinsKetone resinsVinyl resinsDemethylol resins

Machines for padding

Further resins can be classified as per their process of formation/origins:Condensation - this includes Phenol formaldehyde Resins, Alkyd Resins, Polymerization :- Ketone Resins, Vinyl Resins, Dimethylol urea .

The resins are applied in soluble form by padding mangles along with acid catalyst .

A direct coating unit consists of a series of coating heads alternated with drying ovens or tunnels, each one with cooling cylinders at the exit.

This method is used for the following goods:

Rainproof textilesWaterproof canvasCoated fabrics for leather goods and casesCoated fabrics for garment and upholsteryReverse coated fabrics for wall coveringsCoated fabrics for footwear.

FOR CROSS-LINKING TYPE OF RESINSCross linking agents are applied by Pad- Dry- Cure method.

The following primary steps are involved in application of cross linking type resins :Preparation: Processes such as Scouring and Bleaching are carried out.Impregnation: The fabric is impregnated by means of a padding unit. CuringPre curingPost curingPost curing for 100%cottonPost curing for cellulosic blends

It improves the Crease Resistance and Crease Recovery PropertyIt reduces the shrinkage of the fabric during launderingIt imparts a smooth and quick drying propertyIt improves resilience, handle and draping qualitiesIt improves the weight and dimensional stability

It decreases the tensile strength and tear strengthIt decreases the abrasion resistanceIt gives unwanted harsh and stiff feelIt turns the fabric yellow after chlorine bleachingIncorporation of proper softener and catalyst in the pad bath can reduce the loss in the above mentioned properties of the fabric.

ADVANTAGESDISADVANTAGES

WRINKLE-FREE FINISHPermanent press forms an essential part of easy to care finishes or resin finishes which are anti crease finish, wash and wear finishes, durable press finishes and soil release finishes. The technically correct name for such finishes is cellulosic anti-swelling or cellulosic cross linking or resin finish The ability of a fabric to resist the formation of crease or wrinkle when slightly squeezed is termed as crease resistance. The ability of a fabric to recover to a definite degree is called crease recovery of the fabric.

WHY COTTON WRINKLES?The constant stress and strain forces within the cellulosic fibres to adjacent polymer chains cause them to move.Hydrogen bonds being weak can break allowing the chains to slip past each other.So the main cause of crease formation is swelling, bending, folding and pressingTo make cotton crease resistant we need to prevent distortion of hydrogen bonds by means of CROSS LINKING of OH groups of cellulosic chains. Resins are cross linking agents, which form covalent bond on reaction with OH groups of cellulosic materials in acidic medium at a ph of 3-4.

ADVANTAGES OF WRINKLE-FREE FINISHImproves crease resistance and crease recoveryReduces shrinkageImparts smoothness and quick dryingImproves resilience, handle, drapeIncreases weight and dimensional stabilityImproves fastness to lightPartially waterproof and rot proofPrevents inter molecular slippage

DISADVANTAGES OF WRINKLE-FREE FINISHDecreases tensile and tearing strengthDecreases abrasion resistanceUnpleasant odourHarsh and stiff handleHarsh chemical usageYellowing of fabric after chlorine bleaches

EFFECT ON PHYSICAL PROPERTIES

WRINKLE-FREE FINISH FOR WOOLDECATING produces a smooth, wrinkle free finish and lofty hand on woollen and worsted yarn fabrics and blends of wool.Flat fabric treated with 1 to 2 % of durable press resin and then steamed for 3 to 5 minutes. It is sprayed with more durable press resin for a better finish and pressed to achieve a permanent crease effect wherever requiredFor a more permanent set, dry decating is done in a pressure boiler. Wet decating often precedes napping or other face finishes to remove wrinkles that have been acquired in scouring.

METHODS TO PRODUCE WRINKLE FREE COTTONThere are 4 different methods used to produce wrinkle-free cottonPRE-CUREDPOST-CUREDDIP-SPINVAPOUR PHASE

PROCESS FOR APPLICATION OF RESINS PADDING with 75-80% wet pick up at room temperature

DRYING with minimum tension at 70 - 80C

CURE at 120C -150C for 2-5 min Cross-linking and polymerization takes place

WASHING and soaping at 50 -60C for 10 min acidity is neutralized

Softening and drying - rinsed in water with softener

CREASE RESISTANCE FOR SILKSilk fabric has low wet and dry resiliency. Hence, the fabric wrinkles easily during home laundering or when wet. The wrinkle-free finishes are applied in the following fashion;

DEGUMMING OF SILK done using soap for 2hrs at a temperature of 90C

APPLICATION OF GLYOXAL

Glyoxal 5% 10% 15%(owf)Aluminium sulphate 3%(owf)Softener 2%(owf)Liquor ratio 1:20Room temperatureFabric is padded for 30 mins and then cured at 120C

APPLICATION OF CITRIC ACID

Citric acid 6-15% (owf) Sodium hypophospate softner 2% (owf) Liquor ratio 1:20 Room temperature Fabric is padded for 30 mins and then cured at 120C

APPLICATION OF DMDHEU (Dimethylol Dihydroxy Ethylene Urea)

DMDHEU 6% 10% (owf) Magnesium chloride 6% (owf) Softener 2% (owf) Liquor ratio 1:20 Room temperature Fabric is padded for 30 mins and then cured at 120C

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