test

1. Textile Testing

2. Sources for Standard Test Methods
for Textiles:
 American Society for Testing and Materials (ASTM)
 American Association of Textile Chemists and Colorists
(AATCC)
 Federal Standard Textile Test Methods, Standard No.
191
 American National Standards Institute (ANSI)
 International Organization for Standardization (ISO)
 Bureau of Indian Standards (BSI)

3. Atmospheric Conditions for Testing
In order that reliable comparisons be made among different
textile materials and products, and among different
laboratories, it is necessary to standardize the humidity and
temperature conditions to which the textile material or
product is subjected prior to and during testing.
These conditions are:
65 ± 2% relative humidity
70 ± 2°F temperature

4. Strength Properties of Apparel
The strength properties of apparel have traditionally been
considered the most obvious indicator of the serviceability
of apparel.
The strength properties of apparel can be divided into the
following three areas:
 Fabric strength
 Seam Strength
 Resistance to yarn slippage

5. Fabric Strength
 Resistance to tensile force (Breaking strength)
 Resistance to tearing/shearing force (Tearing strength)
 Resistance to bursting force (Bursting strength)
Breaking strength:
The breaking strength of a fabric refers to its resistance to
tensile force. These tests are used for woven fabrics.
Breaking strength of a fabric can be tested in either length
or width or both .

6. Fabric Strength (contd.)
 Tearing strength:
The tear strength of a fabric refers to its resistance to tearing or
shearing force. Resistance to tearing is of importance in clothing
fabrics such as those used for shirting, blouses, interlining and in
military fabrics such as those used for parachutes.
Tear tests are not suitable for knit fabrics, non woven
fabrics, or felts.
 Bursting strength:
Bursting strength is the force, uniformly distributed over a given
area, needed to break a fabric when applied at right angles to
the fabric. These tests are used for knitted fabrics, lightweight
woven fabrics, and non-woven fabrics.

7. Seam Strength
Seam failure in garment can occur because of either the failure of the
sewing thread, leaving the fabric intact, or fabric rupture, leaving the
seam intact or both breaking at the same time.
The strength of a seam or stitching should equal that of the material it
joins in order to have balanced construction that will withstand the
forces encountered in the use of the garment of which the seam is a
part.
The elements affecting the strength of a seam or stitching are:
 Stitch type
 Thread strength
 Stitches per inch
 Thread tension
 Seam type
 Seam efficiency of the material

8. Resistance To Yarn Slippage
 In some garments, before seam slippage occurs, enough yarn slippage
(filling yarns shifting over warp yarns or vice versa) develops to render
the garment unusable, because such failure is not readily repairable by
seaming.
Seam slippage may occur in a garment or household item because of:
1.) A low number of warp or filling yarns to an inch in relation to particular
yarn and fabric construction characteristics.
2.) Too shallow seam allowances (any strain on the fabric at the seam
causes the yarns to shift)
3.) Too tight a fit (undue strain during wear may cause yarns to shift at the
same line)
4.) Improper seam construction (not enough stitches per inch)

9. Fabric Stretch Properties
There are two categories of stretch fabrics based on degree of
Stretchability:
 Power or Action Stretch, provides a fabric with a high degree of
extensibility and quick recovery. The stretch factor generally ranges
from at least 30 to 50% or more with no more than 5 to 6% loss in
recovery. E.g.. Swimwear, athletic clothing, active sportswear, etc.
 Comfort Stretch applies to fabrics with less than 30% stretch factor
and no more than 2 to 5% loss in recovery. Such fabrics are used
for everyday clothing that needs only a moderate degree of
elasticity.
With stretch fabric, comfort is achieved by reducing garment restraint
imposed on the body, through increased fabric “give”.

10. Dimensional Changes in Apparel
 Excessive shrinkage or growth of a garment can make that item
unwearable.
 Garment shrinkage, due to laundering, dry-cleaning, steaming or
pressing, occurs at three levels: fabrics, yarn and fiber.
 The total observed shrinkage is the resultant shrinkage at these
three stages.
 The contribution of each to the total depends on both the fabric and
yarn structure, as well as the nature of the fiber.

11. Fabric shrinkage may be ascribed to one of
the following causes:
 Relaxation: When yarns are woven into a fabric they are subjected to
considerable tensions, particularly in the warp direction, although the filling
yarns are also stretched. In subsequent tentering and calendering
operations this stretch may be further increased and temporarily set in the
fabric. The fabric is then in a state of dimensional instability, and when it is
wetted thoroughly, it tends to recover dimensional stability, which results in
a contraction of yarns, leading to “relaxation shrinkage”.
 Swelling: Shrinkage that results from the swelling and deswelling of fibers
because of the absorption and desorption of water is called swelling
shrinkage. In a loosely woven fabric, the effect of the swelling of the yarns is
greater than in a tightly woven fabric, since there is greater freedom of
movement.
 Felting: Shrinkage that results primarily from the frictional properties of the
component fibers which cause them to migrate within the fabric/yarn
structure is called felting shrinkage. Important for wool fibers.

12. Fabric shrinkage may be ascribed to one of
the following causes:
 Contraction: The decrease in length that takes place in synthetic yarns/fabrics
when they are exposed to temperatures higher than 21°C (70°F). This tendency
towards relaxation shrinkage can be completely eliminated by heat-setting the
yarns. Synthetic yarns that are not heat set before or after they are converted
into a fabric will shrink due to steaming and / or pressing during apparel
manufacturing.
Shrinkage of a garment can occur when it goes through one or more of
the following processes:
Laundering - Mostly relaxation and swelling shrinkage (felting in wool fibers)
Dry-cleaning - Mostly relaxation and swelling shrinkage (felting in wool fibers)
Steaming - Contraction shrinkage in the case of synthetic fabrics
Pressing - Contraction shrinkage in the case of synthetic fabrics

13. Durable Press Evaluation of Fabrics and
Apparel
“Durable Press” is a term used to describe a fabric or garment that will retain its
original shape and smoothness and sharpness of crease through wear and
repeated laundering and require ironing. This term is often used interchangeably
with the term “permanent press”
Durable press/permanent press: This term applies to fabrics or garments
requiring no ironing after laundering.
Wash and wear/minimum care: This term applies to fabrics or garments
requiring touch up or minimum ironing after laundering.

14. Bow and Skewness (BIAS) in Woven
and Knitted Fabrics
Bow: The ASTM (27) defines ‘bow’ as a fabric condition resulting when
filling yarns or knitted courses are displaced from a line perpendicular
to the selvedge and form one or more arcs across the width of the
fabric.
Skewness: is defined as a fabric condition resulting when filling yarns
or knitted courses are angularly displaced from a line perpendicular to
the edge or side of the fabric.

15. Soil/Stain Release Testing
With the advent of durable press and 100% synthetic fibers, the
removal of certain types of soil has become a problem. To help solve
this problem a number of finishes have been developed for use on
durable press and 100% synthetic fiber fabrics. These are called soil-
release or SR finishes. E.g. Zepel (du Pont) and Scotchgard (3M) are
trade names for two durable flourochemical finishes that resist water
and oil-borne stains. Hydro-Pruf and Syl-Mer are trade names of two
durable silicone finishes that resist water borne stains.

16. Water Resistance and Water
Repellency
Water resistance is an important property of fabrics intended for end
uses such as raincoats, tents, umbrellas, etc.
There are three ways in which water can pass through a fabric:
1.) By wetting the fabric, followed by capillary action which brings the
water to the other side
2.) By pressure of the water, forcing it through the opening of the fabric
3.) By a combination of the aforementioned actions

17.  If a fabric were made in which there were no openings between the
yarns, the cloth might still allow water to pass, if the water wet the
fibers
 If a fabric of ordinary weave were made of fibers which had been
chemically treated so that they would not be wet by water, the cloth
would allow much of the water to roll off without penetrating, but if
the water gathered in a thick layer on the cloth or if the water struck
the cloth with much force, it would pass through the openings; as is
in the case of the so-called ‘shower proof’ fabrics.
 The only way to completely waterproof fabrics is to fill the openings
and coat the fabrics with substances which are not themselves
penetrated by water, like, rubber in ordinary raincoats, tars in
tarpaulins, waxes in some tent cloths or plastic coated fabrics.
Fabrics coated with such substances are also impermeable to air,
and therefore, are unsuitable for wear except in extreme cases.
Water Resistance and Water
Repellency (contd..)

18. Water Resistance and Water
Repellency (contd..)
 A Waterproof Fabric is a fabric that is coated or impregnated to
form a continuous wall against the passage of water or a continuous
sheet of rubber or plastic.
 Water resistance is the ability of a fabric to resist wetting and
penetration of water
 Water Repellency is the property of a fiber, yarn or fabric
characterized by its resistance to wetting by water. A water repellent
fabric is one whose fibers are usually coated with a hydrophobic
type compound and whose pores are not filled in the course of
treatment. This type of fabric is quite permeable to air and water
vapor.

19. Water Resistance and Water
Repellency (contd..)
Fabrics are made water repellent by treating them with water repellent
finishes. A water repellent finish permits fabrics to breathe, allowing the
passage of air, water-vapor and perspiration.
Some finishes are durable to dry-cleaning, whereas some are not.
There are two types of water repellent finishes:
Hydrocarbon repellents, which are hydrophobic and oleophilic, repel
water but quickly pick up soil and stains.
Fluorocarbon repellents are both hydrophobic and oleophobic. Not
only are the fluorocarbons outstanding water repellents, but they also
resist oily and greasy substances.

20. Pilling
Pilling is a fabric surface defect characterized by little fiber balls
clinging to a cloth surface and giving a garment an unsightly
appearance.
These fiber balls or ‘pills’ are formed during wear and washing by the
entanglement of loose fibers that protrude from a fabric surface. Fibers
such as wool, polyester, nylon and acrylic have a tendency to pill.
The development of pills on a garment may also be accompanied by
other surface phenomena such as loss of cover, color change, or the
development of fuzz.
The pilling resistance of a specific fabric in actual wear varies with
individual wearers and general conditions of use. As a consequence it
can be expected that garments of the same fabric will exhibit a wider
range of pilling resistance during wear than in laboratory tests.

21. Pilling
Pilling of garments is affected by various factors such as fiber length
and denier (linear density), fiber mechanical properties, yarn twist level,
fabric construction, fabric finishing treatments, and the nature and
activity of the wearer.
ASTM has developed three sets of five photographic standards, each
set corresponding to the size of pills produced: small, medium and
large. The observed resistance to pilling is reported on an arbitrary
scale ranging from No.5 (no pilling or surface change) to No.1 (very
severe pilling or surface change).

22. Snagging
Snagging is defined as a defect caused by the pulling or plucking of
yarns from a fabric surface. The snagging of a specific fabric in actual
wear varies with the individual wearer and general conditions of use.
Snagging is common in women’s hose, light outerwear, and lingerie
where treatment and service use are usually gentle and light. Knits,
used in a more rugged outerwear application, such as men’s slacks,
result in a very high and unacceptable levels of snagging.

23. Abrasion Resistance
Abrasion or wear is the wearing away of any part of a material by
rubbing against another surface. It is essential for consumer
acceptance and satisfaction.
A garment is serviceable only when it can perform useful service. It
becomes unserviceable when it ceases to perform useful service.
Textile products become unserviceable for several reasons, chief
among these is abrasive wear. Carpets are often discarded because of
extensive wear; trousers and shirts because of fraying cuffs and collars,
worn seats and elbows; sheets become threadbare. All of these are the
results of some form of abrasive action.

24. Abrasion Resistance
Abrasive wear is caused by one or more of the following conditions:
1. Friction between cloth and cloth, such as the rubbing of a jacket or coat
lining on a shirt, pants pockets against pants fabric, etc.
2. Friction between the cloth and external objects, such as that on the seat of
trousers.
3. Friction between the fibers and dust, or grit, in a fabric that results in the
cutting of the fibers. This is an extremely slow process and may take years
before it is noticeable; it may be observed on drapery, flags, or outdoor
fabrics.
The resistance to abrasion is affected by many factors, such as the inherent
mechanical properties of the fibers; the dimensions of the fibers; structure of
the yarns; construction of the fabric; and the type, kind, and amount of finishing
material added to the fibers, yarns, or fabric. The resistance to abrasion is also
greatly affected by the conditions of the tests, such as the nature of abradant;
variable action of the abradant over the area of specimen; the pressure
between the specimen and abradant; and the dimensional changes in the
specimen.

25. Abrasion Resistance
Evaluation of the resistance to abrasion may be based on any of the following
criteria:
1. Number of rubs or revolutions required to wear a hole in the specimen.
2. The specimen is subjected to certain number of rubs or revolutions, and then
one of the following is evaluated:
a) Overall appearance, loss in color or shade, signs of damaged yarns,
fibers, and so on
b) Loss in the breaking strength of the specimen
c) Loss in the weight of the specimen
d) Decrease in the thickness of the specimen
e) Change in the air permeability of the specimen.
There are no voluntary or mandatory standard minimum requirements for the
abrasion resistance of various fabrics. Abrasion tests are meaningful when
considered along with other physical properties tests. Together they are very
helpful in predicting a fabric’s performance.

26. Colorfastness
Colorfastness is the property of a dye or a print that enables it to retain
its depth and shade throughout the wear life of a product. Dyes are
considered to be fast when they resist the deterioration influences
(such as laundering or dry-cleaning) to which they will be subjected in
the use for which the fabric is intended.
A change in the original color (shade) and/or staining or color transfer
on the standard test fabric is evaluated by visually comparing the test
specimen to the AATCC gray scale for color change and staining and
chromatic transference scale. The difference in the color change and
the amount of color transfer are given a numerical value ranging from 5
to 1. Class 5 indicates no change in the original color (shade) and/or no
color transfer. Class 1 indicates a noticeable change in color (shade)
and/or heavy color transfer.

27. Colorfastness
AATCC has developed three scales that help visual comparison
between the original color and color change and / or staining of the test
specimen. These scales are:
Gray Scale for Color Change: This scale consists of nine parts of
standard gray chips, each pair representing a difference in color or
contrast (shade and strength) corresponding to a numerical fastness
rating. The results of colorfastness tests are rated by visually
comparing the difference in color represented by the scale.
Gray Scale for Staining: This scale consists of pairs of nominally
white and gray color chips, each representing a difference in color or
contrast (shade and strength) corresponding to a numerical rating for
staining.

28. Gray Scale for Color Change and Staining

29. Colorfastness
Chromatic Transference Scale: This scale makes use of 30 color chips.
The neutral chip representing the horizontal row No.5 as well as the neutral
gray chips were selected to correspond to the gray chips of all the steps on
the gray scale for staining. The chips on the chart are mounted on white
cardboard in five horizontal rows. The rows are placed and aligned so that
every color shows a similar graduation in depth in a vertical line, ranging
from the lightest tints on top to the heaviest tints on the bottom.
For rating purposes the rows are designated numerically with No.5 being
assigned to the top horizontal row that depicts no color, No.4 to the second
horizontal row or lightest colors, and so on to down to No.1 for the bottom
horizontal row or heaviest colors. The rows are mounted with sufficient
space between them to show circular holes cut in the card over each clip in
the five horizontal rows.

30. Chromatic
Transfer
Scale

31. Colorfastness
Evaluations made with the chromatic transference scale should give essentially the
same ratings as those made with the gray scale for evaluating staining. It also
facilitates evaluations of staining, especially when used by a less experienced
technician. Reports on staining arrived at by the use of chromatic transference scale
must clearly state that this scale was used in lieu of the gray scale.
The standard undyed fabrics used in colorfastness testing are multifiber
and 100% cotton.
The source of light is a factor that must be considered in the assessment of
the colorfastness tests. To eliminate the source of light as a variable element, most
of the test methods for colorfastness tests recommend evaluation of the test
specimen with an illumination of at least 538 lux (50-ft candles) on the specimen
surface. The Macbeth shade chamber or booth provides such a light source. Also it
provides daylight and incandescent light, so a test specimen may be evaluated
under more than one lighting condition.

32. Colorfastness to Washing
 Test specimens laundered under appropriate conditions of
temperature, bleaching, and abrasive action.
 The color change of the test specimen and the staining of the
multifiber fabric are visually evaluated.
 The instrument used is called the LaunderOmeter
Colorfastness to Dry cleaning
Test is done with a LaunderOmeter, the same way as that for
colorfastness to laundering except that instead of soap solution, dry
cleaning solution (perchloroethylene) is used.
For most apparel items the ASTM minimum requirement for
colorfastness to laundering or dry cleaning should not be worse than
Class 3 or 4 on the AATCC gray scale for color change and staining.

33. Colorfastness to Light
The resistance to degradation (or fading) of fabric dyes and prints due
to light is an important requirement of a garment.
 The test instrument used in the colorfastness to light tests is called
the FadeOmeter or WeatherOmeter. This instrument uses a light
source, either a carbon or xenon-arc lamp.
Colorfastness to Crocking
Designed to determine the degree of color that may transfer from the
surface of colored textiles to other surfaces by rubbing.
 The instrument is called Crockmeter. Color transferred to the white
test cloth is assessed by comparison with the AATCC chromatic
transference scale or gray scale for staining.
 Should not be more than class 3 or 4 on the AATCC chromatic
transference scale.