Crocking , Laundering, Dry cleaning

Burnt gas fumes

Light (Fastness)

Perspiration

Pressing, Sea water, Water, Chlorinated

pool water

Ozone

Colour Measurement

Colour Specification/Passing/Sorting

Whiteness, Colour difference

Dye strength

Dyeing and Finishing

Mercerization in Cotton

Identification of Dyeclass, Dye strength

Dyeing properties, Identification of

finishes

Evaluation of auxiliaries

Raw Materials and General

Fibre identification and content

Wool grade, Wool Fibre Length

Solvent extractable content

Feather/down mixtures (Lorch)

Non Fibrous Material on Fabric

Ash Content/Moisture Regain

Fibre Melting Point and Cross-Section

Pacifier Evaluation

Hazardous Products – Toys

Yarn Test

Linear density, Twist, Breaking Strength

Filament Count

Fabric Construction

Mass, Fabric Count, Weave, Yarn Crimp

Stitch length in knits, Yarn linear density

Fabric thickness

Frosting

Spectrophotometric Analysis

U.V. Radiation Transmittance, UPF Colour

Fabric Performance Test

Air permeability

Abrasion Resistance -

Accelerator/flex/Taber/ Martindale/Stoll/Stroll/Wyzenbeek

Blocking, Breaking strength, Bursting strength

Chlorine retention, Cold crack

Crease recovery (Angle method), dry or wet

Delamination of coating, Downproofness

Fabric Wrinkle Recovery

Microbiological resistance

Modulus (BSI)

Mothproofing Resistance (IWS)

Oil stain release, pH Value of Water Extract

Pilling resistance – Tumble Box, Random

tumble, Martindale or Brush

“R” / “Clo” value

Electrical Resistivity

Seam Slippage

Shrinkage on laundering,Domestic/Commercial

P.P. Rating

Shrinkage on wetting/steaming/dry cleaning

Snagging resistance, Static cling, Static decay

Stiffness (cantilever test)

Tearing strength – Elmendorf/Single rip or Trapezoid

Water absorption, Water permeability (k)

Water resistance

Water vapour transmission and Diffusion

Yarn shifting

Stretch and Recovery

Carpet Tests

CAN/CGSB-4.129M, CAN/CGSB-4.161M

Aachner (ISO 2551 dimensional stability)

Delamination, Density

Electrostatic properties

Hexapod, Pile face weight

Resilience to Static Load

Separate undercushion CAN/CGSB-20.23

Stain resistance

Tuft bind

Fabric Analysis and Troubleshooting

• Warp streak analysis

• Filling band analysis

• Barré analysis (circular knits)

• Foreign contaminant analysis

• Analysis of off-shade dyeings

• Cotton maturity evaluation

• Determination of sources of fabric holes and weak yarns (finished fabric)

• Fiber defect analysis

General Testing

• Yarn crimp (woven)

• Count and twist from yarn in fabric

• Dye-on-fiber

• Mock dyeing/leveling

• Strip dye/re-dye

• Color reflectance measurement

• Blend analysis

• Analysis of fiber distribution in yarn

• Denier by microscopy

• Yarn cross sections

• Chemical damage assessment

• Dye rate and capacity studies

• PET density determination

• Sonic modulus of filament or tow

ASTM Test Methods

• Fiber identification

• Qualitative textile analysis

• Flammability of apparel textiles

• Differential dyeing of cotton

• Extractable matter determination

• Moisture regain

• Boiling water and dry-heat shrinkage

• Moisture level in textiles

• Bow and skewness test for woven and knitted fabric

• Bulk determination for textured yarns

AATCC Test Methods

• Absorbency of bleached textiles

• Alkali in bleach baths containing hydrogen peroxide

• Appearance of apparel and other home textiles after repeated launderings

• Ash content of bleached cellulosic textiles

• Instrumental color measurement of textiles

• Colorfastness to acids and alkalis

• Colorfastness to bleaching with chlorine

• Colorfastness to bleaching with peroxide

• Dimensional changes in automatic home laundering of woven or knitted fabrics

• Dimensional changes in commercial laundering of woven or knit fabrics

• Extractable content of greige and/or prepared textiles

• Qualitative and quantitative fiber analysis

• Gray scale for color change

• Gray scale for staining

• Mercerization in cotton

• pH of water-extract from bleached textiles

• Whiteness of textiles

• Wrinkle-recovery of fabrics

The term textile can be applied to several types of materials under a couple of

related definitions. The most basic definition of a textile is a material that has been

fabricated by some type of weaving process. This definition is derived from the Latin

root of the work “textile,” textere, which means “to weave.” The term textile can also be

applied to materials manufactured by the interlacing of yarn-like materials, such as

objects made by braiding, knitting, and lacing, as well as some non-yarn based materials, such as felts, in which the fibres have gained coherence by mechanical treatments orchemical processes. In rare cases, pelts, hides, and plastics may also be considered textiles, especially when they are used in the manufacture of clothing items (Leene, 1972).

Textile Fibres

All textiles are made of fibres, that are technically defined as “a unit of matter

with a length at least 100 times its diameter, a structure of long chain molecules having adefinite preferred orientation, a diameter of 10-200 microns, and flexibility” (Landi,

1998, p. 8). Variations in fibres on both the microscopic and the visible levels can have a great impact on the behavior and deterioration of a textile object, and learning the basic properties of textiles can greatly aid in caring for them. There are three major factors that determine the final characteristics of any textile- the fibre form, the source of the fibre, and the method of constructing the final product (Landi, 1998).

Fibre Sources and Forms

Fibres come in one of two forms based on the length of the fibre. A filament is a

fibre of continuous length. Both natural and man made filaments can be extremely long.

Silk worm cocoons, for example, can contain about two miles of continuous twin

filaments, and man made filaments from spinning machines can be even longer. Filament yarns are typically thin, smooth, and lustrous. A staple, on the other hand, is a fibre of limited length ranging from about one-quarter of an inch to many inches in length. Staple fibre yarns tend to be thicker, fibrous, and non-lustrous. (Miller, 1969).

There are three catagories of fibres based on source- natural fibers, mineral fibers,

and man made fibers. Mineral fibres include glass and asbestos and are normally not

directly involved in textile production so only the natural and man-made fibres will be

discussed here. All natural and man-made fibres on a microscopic level are built of

organic polymers, large carbon based molecules composed of a single unit repeated many times. Different types of polymers result in different fibre, and eventually different

textile characteristics (Landi, 1998).

Natural Fibres

Among the natural fibers, silk and wool come from animal sources while the

common vegetable sources are cotton and flax (Landi, 1998 and Miller, 1969). The

silkworm, Bombyx mori, produces silk fibres when it spins a cocoon to protect itself in

the pupa stage (Finch and Putnam, 1985). The fibres are constructed from amino acids

that are cross-linked and generally oriented parallel to the fibre axis. This is referred to

as a crystalline chain structure, and this structure is responsible for the strength of silk

fibres. Wool fibres are also constructed of amino acids except they are arranged into long helical (spiral shaped) molecules making wool much more extensible than silk (Landi, 1998). The fibres, because of this structure, also tend to shrink and mat together when washed in hot, soapy water. This is referred to as felting (Miller, 1969). Wool fibres, like human hairs, are difficult to press into sharp folds, and permanent folds can only be achieved through chemical processes. The natural function of wool is to keep the animal on which is grows dry. Even when incorporated into a textile object, wool fibres retain the ability to absorb up to one-third of their own weight in water before feeling damp to the touch (Finch and Putnam, 1985).

Vegetable fibres are constructed of cellulose polymers which join together to

form long, flexible, and very strong long-chain molecules (Landi, 1998). The function of

flax is to hold the flax plant upright and carry moisture through the plant, thus linen

(fabric that is made from flax fibres) will have a tendency to draw moisture to itself.

Cotton fibres come from the seed heads of the cotton plant and surround the seed before it drops. Both cotton and flax are stronger when wet and humidity is a requirement for weaving cotton fibres (Finch and Putnam, 1985).

Man-Made and Metal Fibres

Man-made fibres were first developed in an attempt to make artificial silk, and

typically have a high degree of crystallinity like silk. While no true substitutes for silk

were ever developed, the research did lead to the development of several types of manmade fibres that can be produced via various chemical processes. These fibres can be divided into two categories- regenerated fibres and synthetic fibers.

Regenerated fibres are made from natural materials that have been dissolved and

then extruded as filaments. Regenerated fibres made from cellulose, commonly termed

rayon, have become the most commercially important. Synthetic fibres include

polyamides (commonly known as nylons), polyesters, and polyvinyls (Landi, 1998 and

Miller, 1969). Metal can also be fashioned into a filament like form and used in textiles.

Consequently, metal threads are sometimes classified as a type of fibre. Gold and silver

alloyed with baser metals such as copper are the most common materials used for metal thread production. The metal is beaten or drawn into very thin laminates and usually wound around a central fibre core that can either be silk, linen, or, in rare cases, cotton. Sometimes the laminate is attached to paper or an animal membrane before it is used. Metal fibres are typically more resistant to deterioration than organic fibres and are often the only intact parts of very ancient textiles (Landi, 1998).

From Fibre to Fabric

Yarn Based Structures

In all fabrics except bonded fabrics and felt, fibres are twisted into thicker

structures called yarns or threads before being used. The process of creating yarns is

called spinning. Yarns can be spun in either the clockwise or counter-clockwise

direction. One direction is termed the Z direction and one is termed the S direction.

After the initial yarn is spun, several yarns can then be twisted together to form ply yarns (i.e. two ply, three ply). These types of yarns are typically thicker and stronger than single ply yarns (Landi, 1998).

Yarns can be woven, knitted, braided, and laced or netted to create fabric. Each

type of structure has an effect on the elasticity and durability of the final product.

Diagrams of the different structures are provided in Appendix A. Woven fabrics consist

of two series of threads that are interlaced at right angles to one another. The two thread series are termed the warp and the weft, with the warp threads running the length of the fabric and the weft threads running the width of the fabric. The simplest form of weaving, plain weave, is shown in figure 1 of Appendix A. The edge on the long sides of a piece of woven fabric is termed the selvedge. The selvedge provides a neat edge to the fabric as well as a secure grip for finishing machinery in machine made fabric. It is often different in appearance and structure to the rest of the fabric. Depending on the method of weaving, the density and type of interlacing can vary, both of which affect the final appearance and handle of the fabric. In general, no matter what method of weaving is used, the fabric will show little capacity for stretching beyond the natural elasticity of the materials in either the warp or weft direction. Instead, a woven piece of fabric will stretch more easily in the bias direction, the diagonal of the fabric that is normally at a forty-five degree angle between the warp and the weft. Knitted structures are formed by interlocking loops of yarn, and, like weaving, there are several methods of knitting fabrics. A weft-knitted structure, so termed because it is constructed of horizontal rows of loops that are individually locked with the corresponding loop in the next horizontal row, is shown in figure 2 of Appendix A. Vertical rows of interlocked loops are termed wales and horizontal rows are termed courses. Knitted fabrics are much more susceptible to stretching and distortion than woven fabrics because any tension exerted on the fabric will distort the individual loops that form the fabric. Knitted fabrics are also easily unraveled, and significant damage can be caused by simply breaking one loop that, in turn, causes other loops to be released. Lacing and netting were formerly hand techniques in which yarns are twined or knotted around each other to form various open structures. Now most lace and netting is made by machine. A simple net structure is shown in figure 3 of Appendix A. Items made by lacing and netting are even more dimensionally unstable than knitted fabrics are (Miller, 1969) and the uses of such fabrics are limited; however, several types of banners were constructed with net bases in the nineteenth century. Advertisements for such

banners can be seen in figure 4 of Appendix A (Collins, 1979). Braiding involves the interlacing of yarns diagonally to form a narrow flat or tubular structure. A typical braid is illustrated in figure 5 of Appendix A. It is difficult to form large braided pieces either by hand or by machine due to the fact that all the constituent yarns must be kept in motion simultaneously and separately. Shoe laces and other kinds of cording as well as decorative braiding are common braided products. The diagonal direction of the yarns allows braids to be somewhat extensible in length and width (Miller, 1969).

Fibre Based Structures

Under the influence of heat, moisture, and mechanical pressure some types of

fibre can be made to mat together to form fabric without the need for yarn. Fabrics made in this way are called felts. Wool and a few other animal fibres are most suited to this type of fabric construction. Felt fabrics have no grain because the fibres do not lie in any particular direction, and because of this, felt can be cut in any direction without fraying or unraveling. Dense felts can be very strong and durable, but are generally stiff and do not drape well. Softer and suppler felts result from less dense fiber structures but there is also a loss of strength and a vulnerability to distortion associated with thinner felts that makes them unsuitable for most purposes (Miller, 1969). Pennants are a common type of historical felt textile in the United States (Collins, 1979). Fibres other than wool can also be bonded together through chemical rather than mechanical processes. These types of fabrics are referred to as bonded fibre fabrics. Bonded fibre fabrics are similar in structure to felt, although some types can be made with the majority of the fibres lying in one direction creating a fabric with a noticeable

grain. Bonded fibre research has not, however, been able to overcome the suppleness and durability problems shared with felt (Miller, 1969).

Textile Finishes

Any given textile will probably undergo one or more finishing processes before it

is used and many processes have been in use for hundreds of years. These processes are too numerous to list here, but they all serve at least one of the following purposes-

• to enhance the appearance of the fabric

• to improve the texture or weight

• to increase flexibility, durability, or ease of care

Finishing processes can be carried out either before or after the textile

construction process. Mercerizing, sizing, and weighing are some examples of finishing

processes that have been widely used for several centuries (Landi, 1998). Mercerizing isa finishing technique used on cotton yarn and cloth. Various concentrations of sodium

hydroxide, an alkali substance, are applied to make the finished textile piece more

lustrous, stronger, more absorbent, and easier to dye. Sizing is also a finishing technique for cotton. Gelatin sizing can be used to give the cotton a coated a papery look, and animal glue sizing made from fish skins can be used to give a greater luster (King, 1985). Weighting is “the process of loading either yarns or fabric with minerals, sugar, or other foreign matters mixed with the dyes, to make the goods look thick or feel heavy” (King, 1985, p.173). In silks this finish compensates for the loss of the natural compound sericin which is lost during the manufacturing process (Finch and Putnam, 1985). Other finishing methods were also used on silks to make lower quality silks appear more costly. These finishes employed gum, starch, oil, and wax based materials, most of which will not withstand washing (King, 1985).

Dyeing is another of the more common finishes with certain dyes becoming more

popular during certain periods. Early bandannas are often referred to as “turkey red”

bandannas because they were dyed a solid red color before a pattern was applied via

bleaching or printing. Figure 6 in Appendix A is an example of this technique (Collins,

1979). Early dyes were obtained from natural sources and varied greatly in quality and

ease of use. In 1856, W.H. Perkin, a British scientist discovered the fist synthetic dye by

accident and this lead to the development of a wide range of synthetic dyes that

eventually replaced natural dyes. Even with synthetic dyes, however, dying is a difficult

and complicated process due to the fact that many dyes on their own are not inclined to

be colorfast and most fabrics on their own are not capable of absorbing dyes, especially

in the case of man made fibres (Miller, 1968). Natural dyes, for example, almost always

required a metal salt to be applied to the cloth before dying to increase the affinity of the

dye for the cloth and, in some cases, to increase colorfastness or change the color of the dye (Landi, 1998).

Cut and Paste From

Basic Textile Care: Structure, Storage, and Display

Elizabeth Bittner

INF 392E Introduction to the Structure and Technology of Records Materials Pavelka Fall 2004

http://webspace.utexas.edu/ecb82/textile_care.doc

During textile finishing, properties are added to textile articles so that they will be appreciated by a large public. To obtain this change, the textile article has to pass through preparatory operations which will facilitate the next operations of dyeing and (chemical) finishing.

1. Preparatory operations

The preparatory operations performed are :

1.1 Desizing

Operation during which the sizing product applied to the warp yarns before passing onto the loom is removed.

In the case of woven or knitted fabrics and during spinning, the yarns are often treated with oil or wax to augment the velocity and to assure a better quality. On the other hand, these lubricants have a negative effect on dyeing (they prevent the colorants from penetrating into the fibres.

Cleaning (also called desizing or boiling off) removes the oils, waxes and other dirty spots.

Moreover, because most processes are performed under tension, what tends to elongate the fibres, yarns and fabrics, the cleaning process allows them to take back a desired shape by relaxing them.

There are two cleaning methods: desizing with water and detergent and dry-cleaning.

1.2 Washing

During the washing process, all improper products are removed from textiles such as grease or dust… that usually remain on natural fibres or dirt on chemical fibres.

In the case of wool, carbonising is often associated with washing to remove vegetable materials (thistles, straw…) from woollen fibre flocks.

1.3 Mercerising

This adds a better resistance to cotton, lustre and a higher capacity to absorb water and chemicals by modifying the internal structure (amorphous and crystalline zones).

Mercerised cotton is often used for sewing thread.

1.4 Bleaching

Certain fabrics need to be bleached before dyeing or to arrive at very white products. This is in particular so for cotton, linen, ramie, etc., since they are not white in their natural state.

Textiles that will be dyed in very pale colours deed to be bleached beforehand to obtain the right shade.
Fabrics that are white in their final usage are usually bleached and then treated with an optical azure to obtain a very bright and beautiful white

Bleaching may be done by a dyeing apparatus or on a continuous stenter. On the continuous stenter, the fabric is pulled through a series of bleaching and washing baths in its full width by means of rollers. Bleaching is either done with chloride or peroxides depending on the fibre and applied colorants. However, extreme care is needed to neutralize any residual chloride before dyeing if chloride is used during bleaching.

2. Dyestuffs

Dyestuffs used to add colour to textiles are chemical agents known as dyestuffs or pigments. Dyestuffs are most frequently used. There are hundreds of available dyestuffs. They are subdivided in several categories. Each one of them is defined by its chemical structure. The most frequently used dyestuffs are :

Direct dyestuffs: used on celluloid fibres (such as cotton, linen, rayon…). They offer a wide variety of colours but the colours are not as bright of intense as one may wish. These dyestuffs have a poor fastness to washing.

Reactive dyestuffs: used on celluloid fibres, protein fibres (wool and silk) and polyamide. These dyestuffs offer a good fastness and allow to obtain very bright colours.

Vat dyestuffs: may be used on cotton, acrylics and polyamides. They are regarded as having a better fastness than any other dyestuff class. They are used for textiles requiring colours with an enhanced fastness to commercial laundering against high temperatures and sometimes to bleaching. (Examples: uniforms, commercial tablecloths, etc). These dyestuffs contain two forms: one is reduced, the other oxidized. Both forms very often contain different colorations.

Acid dyestuffs: used on polyamide, elasthane and some specialised acrylics. These dyestuffs offer a wide variety of bright colours, but their fastnesses vary according to the different dyestuffs inside this same classification. According to the dimensions of the dyestuff’s molecule, there are three categories each of them needing a distinct pH value.

Cationic or basic dyestuffs: mainly used on acrylics. These dyestuffs produce bright colours with an excellent colour fastness. Disperse dyestuffs: used on polyester, polyamide, acetate and others. A fine colour variety is available with these dyestuffs but their colour fastness may vary considerably.

Pigments represent another category of applied dyestuffs. Whereas most dyestuffs are diluted in water, absorbed by fibres, and in most cases, chemically bonded with the fibre, pigments are deposited onto the surface. They cannot adhere to the fabric without adding a binding agent. This binding agent is usually mixed with the pigment and acts as an adhesive. Pigments are principally used for printing operations and for the coloration of melted polymers before extruding certain synthetic fibres.

3. Dyeing

Dyeing and printing are applied to colorise fabrics. The quality of the dyeing and printing is characterised by the fastness to light, water etc.

In the dyeing process, the textiles are dyed on their entire surface regardless of their presentation: fibres, slivers, hanks, fabrics or confectioned clothing.

In order to dye, one prepares a bath in which one dissolves the dyestuffs and chemicals that are necessary to the process.

By bringing the textile material into contact with the bath, the dyestuff is absorbed by the material where it remains more or less fixed.

The actual dyeing processes depend on the nature of the textile material and the type of dyestuff.

Dyeing or applying colour may be done during different steps in the production process. This is generally determined by the final use of the product and sometimes by fashion trends. The particular step where the product is dyed determines the coloration process to be used.

The five main dyeing procedures are :
· In-mass dyeing (during the extrusion of synthetic fibres)
· Fibre flock dyeing (the fibres are dyed before spinning)
· yarn-dyeing
· piece-dyeing (after weaving or knitting)
· garment-dyeing or product-dyeing

Rem. : There are special effects that can be obtained by dyeing blends, such as polyester/cotton. These are :
1. cross dyeing – produces multicolour effects in a yarn or fabric blend by selecting dyestuffs with different affinities to different fibres. When the blended fibres are dyed, each of them is dyed in a different colour.
2. Union dyeing – produces an even colour in the yarn or fabric blend. The dye bath contains different dyestuffs producing the same colour on each fibre of the blend.
3. Shade on shade dyeing is carried out when variants of the same fibre are used in the same yarn of fabric to produce different shades of the same colour in a single bath. This method is often used for carpets.

4. Printing

The objective of this technique is to print certain patterns on fabrics.

Prior to printing, one prepares a paste made of dyes, water, chemicals and a thickening agent preventing the paste to smear over the surface of the fabric.

The most widely spread printing systems use rotating machines consisting of perforated cyindres reproducing printing patterns .

The printing paste is introduced into the cylinders. By running through the cylinders’ perforations it is deposited onto the fabric.

Another and more modern printing method is called transfer printing. It consists of transferring at one the complete pattern onto the fabric on the basis of a special paper by applying heat or pressure. The printed patterns may be applied onto yarns, fabrics or confectioned garments.

Most commercial prints are made by one of the four following methods :
o Flat printing
o Roller printing
o Transfer printing
o Ink Jet printing

5. Dyestuff quality

The quality of dyestuffs and prints is determined by fastness.

In this way, a suspended curtain that looses its colour over time has a bad fastness to light and is therefore of a poor quality. A shirt loosing its colour by washing it has a bad fastness and is therefore of a poor quality.

Depending on the use to which a textile article is destined, the particular fastness characteristics are defined. For example: for a curtain a good fastness to light is required, for a shirt, a good fastness to transpiration and washing is demanded, and an upholstery fabric for a chair should possess a good resistance to friction and a good fastness to light .

6. (Chemical) finishing

(Chemical) finishing adds qualities to fabrics which they lack; it eliminates certain flaws or improves their touch and aspect.

First of all, one has to distinguish between functional and aesthetic finishing. Functional finishing improves the product’s performance under conditions of specific use whereas aesthetic treatments improve the appearance or touch (sensation) of the fabric.
Secondly, there is a distinction between chemical treatments (wet) and mechanical treatments (dry).

A third way to classify treatments is done by their degree of permanency. These classifications are :
o Temporary – the finish is removed by washing or dry-cleaning; e.g. calendaring (similar to pressing).
o Renewable – finishes that may be applied again. Examples of this type of treatment are starch and dirt repellent finishes.
o Durable – a treatment that will last the entire life of the product but with decreasing efficiency.
o Permanent – finish remaining entirely the same during the entire life of the product.

6.1 Chemical finishing

Chemical treatment to add particular qualities and characteristics to fabrics. The most commonly used treatments are :
- Crease-resistant treatment, allowing to avoid the tendency to crease of cotton fabrics.
- Shrink-resistant finish limits the tendency to shrink of cotton.
- By applying the water repellent and oil repellent finish, one avoids that fabrics absorb water and oil.
- Other finishes add specific properties to fabrics to starch and reinforce them.
- The softening finish improves the touch of the fabric.

6.2 Finishing

Mechanical or physical treatments to give particular qualities and characteristics to fabrics. The main finishing operation are :
Calendering – consists of submitting the fabric to a high pressure between two cylinders at high temperature, which will give a bright and ironed aspect. There is a variant to calendering called honeycomb by which embossed patterns are engraved on the surface of the fabric.
Raising and sueding consist of cutting certain fibres on the surface of the fabric to give them a soft and velvety aspect. Raising is obtained by grating the fabric with metallic points, and sueding by the friction of sandpaper.
Sanforising allows to prevent the cotton from shrinking when washed. It is carried out by compressing the cotton to reduce its shrinking capacity .

6.3 Coating

Application of a rubber, (polyvinyl chloride) or PU (Polyurethane) paste on one or both faces of a fabric. As soon as the coating is dry, it is firmly bonded to the fabric. As an example of coated fabrics, one can mention tarpaulin. Several coating processes (in solvant or aqueous medium) are possible.