Fabric Finishing and Aesthetic Finishes

What is a Finish?

A finish is any process that is done to a fiber, yarn, or fabric either before or after fabrication to change: the appearance (what is seen) the hand (what is felt) the performance (what the fabric does) or a combination of these properties. Finishing processes are carried out to improve the natural properties or attractiveness of the fabric and to increase its serviceability.

Classification of Finishes

Aesthetic finishes Functional finishes - special purpose finishes According to quality: Temporary Semi permanent Permanent According to the type: Chemical finishes Mechanical finishes

Applied Design vs. Structural Design

Applied design: applied to fabric to alter some visual, textural, hand or other aesthetic dimension of the fabric Also known as surface design Structural Design: incorporating the design as the fabric is produced.

AESTHETIC FINISHES

Change appearance or hand; may change fabric name Many possibilities from same gray goods

Luster

Change light reflectance; done by calendaring Glazed: friction calender produces high surface glazed as one cylinder rotates faster (glazed chintz, polished cotton) Ciré: similar to glazed, hot calender glazes surface; adds more luster (ciré taffeta, ciré satin)

Routine Finishing Steps for Wool Fabrics

Crabbing - used to set wool fabrics - fabric is immersed in hot water, then cold water, and pressed between rollers Decating produces a smooth, wrinkle-free finish and lofty hand on woolen and worsted fabrics and on blends of wool and manufactured fibers Carbonizing, the treatment of wool yarns or fabrics with sulfuric acid, destroys plant matter. In pressing, the fabric is placed between metal plates that steam and press the fabric

Chemical Finishes

Fabric is chemically changed

Aesthetic Finish: Texture and Hand

Finish alters texture and hand of fabric (can feel effect of finish). Embossed: produces raised or 3-D design (embossed cotton)

Drape

Finish modifies drape of fabric Transparent and crisp: Parchmentize: treat cellulose with acid (organdy). Burned-out (deglaze): print chemical on fabric that dissolves one fiber

Length/Duration of Finish

Finishes can be classified by how long they are effective. A permanent finish, such as mercerization, lasts the life of the item, or reapplied by dry cleaners. A durable finish may last for the life of the product, but its effectiveness diminishes with use or age. A temporary finish lasts until the item is washed or dry-cleaned. A renewable finish can be applied by consumers

Performance of Aesthetic Finishes

Finishes change fabric performance. Inherent problems may develop with finish. Permanence related to process and fiber content Thermoplastic fibers combined with heat tend to create permanent changes Resin-based finishes tend to be durable.

Sustainability of Finishing

Finishing transforms a harsh and unattractive fabric into an attractive one. Unfortunately, the impact of this transformation can be significant. Almost every step in finishing a fabric has an impact on the environment

Finish Definitions

Gray (grey, greige, or loom state) goods are fabrics that have been produced but have received no wet- or dry-finishing operations. Converted, or finished, goods have received wet- or dry-finishing treatments such as bleaching, dyeing, or embossing.

Why are fabric finishes used?

Improve the appearance - color, pattern or sheen. Change the texture of the fabric - embossing, brushing or smoothing improve the feel - softer, crisper, firmer. Improve the drape (how the fabric hangs) - weighted Improve wearing qualities - crease resistance, stain resistance, flammability, waterproof etc. Modify care requirements - easy wash, quicker drying times, colorfast, less shrinkage.

Routine Steps in Producing a Fabric

In fiber processing, cotton fibers are processed separately from polyester fibers because of the differences in properties of the two fiber types. In yarn processing, the fibers are aligned, blended, and twisted. The compact fibers are loosened and aligned in a parallel fashion before the yarns are produced

Yarn preparation involves several steps.

In sizing (also known as slashing), warp yarns are treated before being threaded into the loom for weaving. The process of creating the fabric, or fabrication normally follows sizing. Preparation or pretreatment of fabric is an important step in dyeing and finishing.

Alternate Preparation Steps

Mercerization is the process of treating a cellulosic fabric or yarn with an alkali. In slack mercerization, cotton fabric is dipped, at low tension, into a weaker caustic soda solution for a shorter time before neutralizing and washing. An ammoniating finish is an alternative to mercerization used on cotton and rayon.

TECHNIQUES OF FINISHING

NATURE OF FABRIC i.e. chemical composition, state, weave etc. this determines the transparency, luster, fullness, weight, whiteness etc. i.e. the appearance PHYSICAL PROPERTIES OF FABRIC - i.e. softness, stiffness, tensile strength, elongation, shrinkage property, insulation etc. END USE OF MATERIAL- e.g. non shrinking, non-creasing, crease retention, draping, resistance to abrasion

What Can Finishing Do?

Provide aesthetic value Soften fabric or change the hand Adds to durability Adds to comfort Provide safety Improves performance

Finishing Technologies

There are a number of processes that can be used to finish textiles. Selection of the processes depends on many factors: Fiber content, yarn type, fabrication method, facilities available, cost, government regulations, and company policies

Calendering

To give soft and smooth surface to the fabric To give luster or glaze to the fabric To give silk like appearance To decrease the air permeability To flatten the slubs

Applied Design Compared to Structural Design

Usually less expensive May tender fabric Decision made later in process Less time-consuming Permanent Durable or temporary Maybe off-grain

Flocked

add surface fiber with adhesive for localized pile effect

Color is normally

added to the fabric after the routine finishing steps discussed previously

Backfilling machine

applies finishes

padding machine

applies finishes and dyes

Napped

brush fibers to surface for fuzzy, soft hand; increased warmth and beauty; contributes to water and soil repellency (flannel, falnnelette, fleece)

Enzyme wash

cellulase enzyme removes surface fuzz; decreases pilling and fabric weight

Chemical Wash

chemical alters fiber surface

Puckered surface

chemical printed on nylon or polyester shrinks fabric

Abrasive Wash

chemically saturated abrasive material tumbled with fabric

Expanded foam

compound expands with heat, three dimensional

Fulled

controlled shrinkage (compacted) of wool fabrics; improves hand and appearance

Ajouré embroidery

embroidery on ground structure and dissolve it leaving an open area with a pattern or figure

Emerized, sueded, or sanded

fabric abraded to create soft hand; peach skin look

Mechanical Finish

fabric is mechanically distorted or altered with heat or pressure

After finishing

fabrics are inspected for defects and repaired or reworked.

Brushed

fiber ends swept off fabric after shearing

Additive Finish

finishing chemical added to fabric to produce desired effect

Fabric inspectors mark

flaws and record its quality at the same time

Coronized

heat setting, dyeing, and finishing glass

Special-purpose finishes

include wrinkle-resistant, soil-release, and fabric-softening finishes. Because of the frequent wetting of textiles in finishing, drying is necessary.

Beetled

mechanical flattening of yarns to make weave appear tighter (damask, crash)

Weighting

metallic salt added for stiffness (weighted silk)

Sheared

pile or nap cut to controlled height; patterned or not

Plissé

print NaOH on cotton, shrinks, creates puckered effect; areas dye darker (plissé

Permanence related to

process, fiber content, and type of finish

Subtractive Finish

something removed from fabric during finishing to produce desired effect

Creeping

special compacting process for hand, comfort stretch, and drape

Embroidered

stitch thread, beads, ribbons, or other on fabric; multi-head; shuttle, or schiffli (eyelet)

Sizing

temporarily adds body and weight

Plasticize

thin polymer layer; higher glaze.

Pleated

variation of embossed

Moiré

water-marked design on ribbed fabrics; two fabrics calendered or etched calender (moiré taffeta, moiré ottoman).