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Chemical testing of
textiles
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Introduction
Chemical analyses of textiles is an interdisciplinary subject:
Textile: fibers, textile evaluation
Industrial: textile technology and industry
Ecological aspects: waste water, ecology
Chemistry: chemical reaction
Analytical chemistry: elemental and structural analyses, analytical techniques
Physics: mechanical testing of textiles
+ criminology !!!
(similar methods, similar important results...)
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Comparison between chemical and
chemical testing
Aim is joint: detection of fiber damage, observation of textile properties, testing of
chemicals…
Chemical testing: 1 testing (maximal 3 tests) = approximately 5 g
Mechanical testing: about 5 tests = approximately 100 g
Chemical testing can detect latent damage of fibers – low level damage, which will
change the fiber property in life cycles if textile. Is possible identify critical
settings of industrial textile production.
Relative response
Chemical test
Mechanical test
Changes in textiles
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Suggested literature
- text book only in Czech Quiguo Fan: Chemical testing of textiles, Woodhead, 2005, PDF or
book
- Technical standards
- basic literature of chemistry
- information about fibers
- laboratory manuals
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Technical standards - subject
Technical standard = „cookery-book“ for laboratory
= technical rules
= or technical solving for repeated processes
= or definition of technical terms
= or safety of processes
Standardization is necessary if is it measurement not easy (clear)
Aim of standardization is easy communication between industrial or business
peoples. Technical standard is an agreement.
Using of these technical standards is voluntary. You can set anything other as a
standard of communication between you and yours commercial partner.
In cases of safety and health are the technical standards obligatory!!!
Technical standards: stability of results, accurate results, right results…
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Technical standards
Technical standards – harmonized internationally
Czech Republic: national Czech standard CSN = European standard EN =
international standard ISO
Czech technical standards - now full harmonized with EU and ISO
In praxis:
+ technical standard from other countries:
DIN (Germany), GOST (Russia), BS (GB), ASA (USA), ASTM (USA).
+ Company standards:
Products, internal standards, specific tests
Czech technical standards are printed and prepared by Czech Normalization Institute. In
other countries is it other authorized subject.
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Technical standards
Technical standards are divided to groups (high quantity = organization).
System of Czech National Standards (CSN):
0 – general testing
1 – fibers
2 – yarns
3 – fabrics for clothing
4 – technical fabrics
5 – woven structures
6 – special textile products
7 – confection
8 – ropes
9 – finishing
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Technical standards - example
ČESKÁ TECHNICKÁ NORMA
ICS 59.080.01
Srpen 2001
Textilie - Postupy domácího praní a sušení pro zkoušení textilií
ČSN EN ISO 6330
80 0821
idt ISO 6330:2000
Textiles - Domestic washing and drying procedures for textile testing
Textiles - Méthodes de lavage et de séchage domestiques en vue des essais des textiles
Textilien - Nichtgewerbliche Wasch-und Trocknungsverfahren zur Prüfung von Textilien
Tato norma je českou verzí evropské normy EN ISO 6330:2000. Evropská norma EN ISO 6330:2000 má status české
technické normy.
This standard is the Czech version of the European Standard EN ISO 6330:2000. The European Standard EN ISO
6330:2000 has the status of a Czech Standard.
Nahrazení předchozích norem
Tato norma nahrazuje ČSN EN 26330 z února 1996.
© Český normalizační institut, 2001
62480
Podle zákona č. 22/1997 Sb. smějí být české technické normy rozmnožovány
a rozšiřovány jen se souhlasem Českého normalizačního institutu.
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Technical
standards example
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ChTT – aims and methods
Testing of:
- textiles (fibers, yarns, fabrics, clothing…)
- textile chemicals (surfactants, dyes…)
- textile liquors
- water
+ analyses of production problems
Methods:
- Logic
- Chemistry (aspecially analytical chemistry)
- dyeing tests
- laboratory simulation of comertial production
Aims:
- Elimination of problems in textile production and using of textiles
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ChTT – aims and methods
Typical questions and problems:
1) Impurities in fibers
Haw much fibers and impurities in our input? Which kind of impurities?
Will I have problem with these impurities?
2) Composition of textile
What kind of fibers?, Proportion of selected fibers in mixture?
3) Fiber damage analyses
What is a reason of fiber damage? It is a chemical damage?
4) Testing of chemicals using in textile production
It the chemical same as last time? Hay much water is inside? Haw much
active component in solution?
5) Testing of treated textiles
IS treatment stable to washing? Is it „high level“ treatment?
6) Looking for damage reasons
Where was the fabric damage? What is the reason?
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Analyses of defects on textiles
Analyses of reason and place of textile damage/defects is complicated
Typically: we detect problem on finished textile (after 5 or 10 steps of
production), many times are production lines very complicated and
closed
Analyses is based on detail knowledge :
1) of production steps
2) of influence of inputs in the used technology
3) properties of textile material
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Analyses of defects on textiles
We see color/visual differences on textile (stains or ...)
What is the reason?
- Different dye quantity (possible, but rare)
- Other textile structure (other optical properties)
- Other properties of fabric (problem of yarn density,
- Other properties of yarn ( longitudinal levelness of yarns ...)
- Differences in fiber fineness
- Oil on fibers
- Mechanical damage
…
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Analyses of defects on textiles
Typical defects:
Visual unevenness – deformations, folds, stains, smudge ...
Levelness of color is easy to find!!
Unleveled of mechanical parameters, finishing, tenacity... Is not
possible to identify – here are not problems !
Changes of color (stains ...) are complicated problems !!!
Example:
NO !
NO !
YES !
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Analyses of defects on textiles
1) Studying of production history (time table, technical parameters,
setting, history of other similar products with and without stains... )
2) Archiving of samples, especially stains
3) Archiving of textiles after single steps of production...
4) Information about people in production (peoples are weak points
in industry production)
Position of stains in textile +
Cycling of stains
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Analyses of defects on textiles
Define which part of textile has different color?
Is it yarn (warp or weft) ? Or fibers? Or are the stains on textiles
without connection to textile structure?
According the answers is possible find the reason of defect !
If you know the history of all textiles in your factory, you can find
easy the differences between production of standard textile and
textile with stains..
Example:
Weft defect
Example:
Warp defect
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Analyses of defects on textiles
Season influences:
- Different humidity of air
- Different water (for example:
hardness)
- Different temperature
- Different people (in summer – more
students, brigade-worker...)
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Reasons of fiber damage
Fibers can be damage in any steps of its production and processing
such as: fiber formation, Drawing, Spinning, sizing, weaving, desizing,
bleaching, boiling, mercerization, dyeing, washing, finishing, using, storage …
Reason of fiber damage:
•Chemical
•Photo - chemical
•Thermal
•By microorganisms
•By insects
•Mechanical
•…
In many cases: more reasons, ability to damage increases after the first damage
(damaged fibers are more sensitive for later damage) – synergic effects
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Chemicals on textiles
Acids and alkalis on textiles are typical reason of problem and defects
on textiles
(NaOH, Na2CO3 – boiling, washing, mercerization...)
(acids – dyeing, carbonization...)
pH measurement:
1)Direct measurement with solution of pH indicator (spraying –
mapping of pH distribution)
2)Using of wet pH-indicate paper
3)Water dilution and measurement of pH by pH-meter
Oxidative and reductive chemicals on textiles – reaction with solution
of iodine + detection with starch (KI+NaClO = I, I+starch=blue color)
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Analyses of defects on textiles
If you thing, that the reason of problem is find:
Repeat the reason of defect in laboratory !
... To be sure with your reason ...
testing
idea
False reason ?
possible reason
validation of
reason
real reason
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Right answer is important !!!!
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Reason of defects by consumers
Consumer = generator of stochastic (accidental) processes
Few examples from our department:
problem
Cotton textiles local decolorization
Legs are at the down part decolorized
Decrease of tenacity of cotton table
cloth
Stains on synthetic fabrics
reason
Consumer used skin salve containing peroxidic
chemicals
Consumer shoes were disinfected on the airport in
the time of infection diseases – by solution of NaClO
and his legs are třo long
Table emitted acid vapors and decomposed cotton
Cotton fabric was destroy to dust after
light touch
Stains (maps) on synthetic fabrics
Woman-consumer used perfume – this organic
solvents extracted disperse dye from fibers
On textile was evaporated and concentrated solution
of H2SO4
Ironing of textiles at high temperature
High sensitivity of cotton to light
Fibers were oxidative damaged by wrong bleaching
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Basis of laboratory work
Samples should be „standard“ – typical for tested material, with the same
paramethers, concentrations…
Samples should be defined
For example: You obtain bale of raw wool fibers – you have take samples not
only from surface of bale, but from the inside of bale as well.
For example: testing of textile piece in many places
For examples: big drum with chemical – homogenization before sample taking
sample
analyses
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Basis of laboratory work
Document of all your steps !!
for example in laboratory day-book
Right description contains answer on these questions: Who? What? Where?
Why? Haw many times? According which standard? Result?
Right laboratory day-book is basic help to find and solve long-time
problems. Changes in raw material, in products...
In laboratories are standardly tested properties if water, all used chemicals,
products... = help in production stability and quality
Business is based in seted properties of material according internal or
global technical standards.
Same times is necessary to write „REPORT“ about test.
Report should contain all information as in laboratory day-book +
standardized adjustment
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Basis of laboratory work
Economical point of view:
Defect on textile = price is zero !!!
Example calculations:
1 m2= 5 USD
One textile piece in discontinual production=1000m2 = 5.000USD
Or continual production: velocity is 5 m2/s + time 10 minutes (600
s) = 3.600m2 = 18.000USD
Manager would like find the responsive person – „Who caused this lost?“
... Laboratory tests are important (serious) !
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Basis of laboratory work
Which method should be used?
1.Technical standard (ISO – EU – national...)
2.Common standard
3. Scientifically literature
4.Your new standard
Setting of testing methods between commercial partners.
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Other aim of chemical
laboratory in factory:
Setting of right care of
textile products
- Right temperature of
washing
- Right ironing …