RESIN FINISHING

RESIN FINISHING1RESINSResins are the chemical groups applied as wet finishes.Synthetic resins are complex organic products of high molecular weight.They are the principal chemical ingredient in many crease-resistant finishes and also for durable press.Used primarily on cellulosic and cellulosic-blend fabrics.2RESINSThere are several types of resins, but most belong to the urea formaldehyde or related groups of organic compounds.These formaldehyde components have been suspected of being carcinogenic(cancer causing) materials.Dimethyl urea glyoxal compounds(non-formaldehyde) are used less extensively due to their relatively high cost and limited effectiveness.

3RESINSThe most widely used agents are DiMethylol DiHydroxy Ethylene Urea (DMDHEU) and DiHydroxy DiMethyl Ethylene Urea (DHDMEU).Resins are colorless and are applied to fabrics in liquid form.

4RESINSThen it is dried and treated at high temperature (curing), causing the resin to react chemically with the cellulosic component of the fabric.Curing requires from 30 seconds to 2 minutes at temperatures of 300F to 350F (145C to 165C).

5RESINSThe temperature depends on fabric type and the amount of resin used.Resin finishes are usually classified as durable finishes(rather than permanent).Curing can be performed at lower temperatures, but this requires long exposure time.

6RESINSResins cause changes in the hand, drapability and physical characteristics of textiles.Although many benefits are achieved through these changes, there are also some shortcomings.7RESINSModifications done by the resins:Add stiffness to fabrics and thus are used as stiffening agents or to create a firm hand.Stabilize fabrics in the same shape or configuration as when the resin is cured.Fabrics cured in a smooth, non-wrinkled condition will return to that shape after being wrinkled in wear.

8RESINSFabrics cured with creases in garments will retain these creases.Yarns in fabric are stabilized and resist shrinkage in laundering.Fabrics become less moisture absorbent and thus dry more rapidly.They are also less comfortable in warm, humid conditions.9RESINSResins combine chemically with cellulosic fibers to cause significant reductions (up to 50%) in abrasion resistance, breaking strength and tear strength.Most resins produce an offensive fishlike or formaldehyde odor in fabric.This odor eventually disappears on exposure to air or laundering.10RESINSEthylene glycol and similar compounds added to the resin bath have been found to be very effective in eliminating or reducing this odor.Resins have an affinity for oily soils, creating a soiling problem which can be avoided by soil-release finishes.The degree of these changes is dependent on the amount of resin applied (Resin add-on).11RESINSAdd-on may range from less than 2% for certain crease resistant finishes to 10% for some durable-press applications.

12PLISSEIt is a permanent finish, produced on cotton by the action of sodium hydroxide.The sodium hydroxide is printed on the fabric as a paste.The fabric shrinks only where the sodium hydroxide is applied, producing a puckered effect.Plisse fabrics usually do not require ironing.13PLISSEAn inexpensive plisse can also be made by embossing, but the effect does not last as long as in plisse made with the use of a chemical.When the sodium hydroxide is applied as lengthwise stripes, the fabric puckers and takes on the appearance of seersucker.Seersucker is a fabric with a lengthwise striped puckered effect.14PLISSEIt is produced by alternate stripes of loose and tight warp yarns.Plisse is a cheaper imitation of seersucker.It does not have the depth or degree of pucker that is common to seersucker.Seersucker can be distinguished from plisse by stretching the fabric in the warp direction.Plisse puckers stretch out flat and seersucker puckers do not.15PLISSE

16PLISSE

17SEERSUCKER

18SHEARINGIt is a process used to cut off surface fibers on fabrics.It makes the surface of napped fabrics uniform and uniform pile height in pile fabrics.A fabric shear, the high speed machine that performs this operation, has cutting action similar to that of a lawn mower.The blades are stationary and the fabric moves to the cutting blades.19SOFTENINGFabric softeners or hand builders improve the hand of harsh textiles, which may develop as a result of resin finishes or heat setting of synthetics.Softener types include anionic, cationic and nonionic.Anionic softeners are usually sulphonated, negatively charged fatty acids and oils that must be padded onto the fabric because they lack affinity.20SOFTENINGAnionic softeners are often used on cellulosic and silk fibers.Cationic softeners have good fiber affinity but they tend to yellow with age and may reduce the absorbency of the fabric.Nonionic softeners are usually made up of complex alcohol.21SOFTENINGSilicone softeners produce a dryer hand as compared with that of the other compounds.Better wrinkle resistance and durability occur when these softeners are combined with durable press finishes.

22STIFFENINGFabric stiffening may be done with several chemical finishes.Starch of various types is widely used as a stiffening finish.In addition, the starch also adds body and weight to the fabric and customers may misunderstand poor fabrics to be good.

23STIFFENINGStarch finishes are temporary and need to be restored by laundering to maintain their stiff hand.Resins are widely used as stiffening agents.Use of resins on cellulosic fibers causes tendering when heavy add-ons of the resin are used.24STIFFENINGAcid stiffening involves the rapid immersion of fabric in sulphuric acid, followed by immediate neutralization in sodium hydroxide.This finish is permanent.Example : Organdy25BEETLINGBeetling is a finish used on linen and fabrics resembling linen.As the fabric revolved slowly over a wooden drum, it was pounded with wooden hammers until the yarns flattened into an oval cross section.The weave becomes tighter than it was.Greater surface area increased fabric luster, absorbency and smoothness.

26PARCHMENTIZINGA special acid treatment given to cotton for permanent stiffness.The application of a carefully controlled acid solution causes the surface of the yarn to become softened and gelatin-like.An after-wash in cold water causes the gelatinous outer surface to harden, forming a permanently stiffened exterior.Example: permanently finished Organdy.

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