Textiles III: Textile Testing and Quality Control, Textiles and the Environment, Recent Developments in Textiles and Apparel, and Types of Research
2. GSM, shrinkage, colourfastness and pilling
GSM is the mass of a fabric in grams per square metre, the trade's measure of fabric weight. A GSM cutter punches a circular specimen of 100 square centimetres, which is one-hundredth of a square metre, so the specimen's weight in grams multiplied by 100 gives the GSM: a specimen weighing 1.8 g is a 180 GSM fabric. With a cut square the rule is the same: a 10 cm by 10 cm square weighing 1.5 g is 150 GSM. Light shirting may be around 100 GSM and denim well over 300.
Dimensional change is measured by marking a known distance on the specimen, laundering and drying it under a standard procedure, and re-measuring: shrinkage per cent = (original length − length after washing) / original length × 100. A 50 cm benchmark that measures 47 cm after washing has shrunk 3 / 50 × 100 = 6 per cent. Growth, the opposite, is reported as a negative change.
| Test | Method | Rating |
|---|---|---|
| Colourfastness to washing | Specimen laundered with adjacent undyed fabrics | Grey scales 1 to 5 for change in colour and for staining; 5 means no change |
| Colourfastness to light | Exposure to a xenon arc lamp or daylight beside blue wool references | Blue wool scale 1 to 8; 8 is the most lightfast |
| Colourfastness to rubbing (crocking) | A white cloth rubbed on the specimen, dry and wet, in a crockmeter | Grey scale for staining |
| Colourfastness to perspiration | Specimen soaked in artificial acid and alkaline perspiration | Grey scales |
| Pilling | Specimens tumbled in a pill box or rubbed in a Martindale tester | Compared with photographic standards, 1 (severe) to 5 (none) |
3. Textiles and the environment
Textile wet processing uses large volumes of water, energy and chemicals, and discharges effluent high in colour, salts, total dissolved solids and chemical and biological oxygen demand. Certain azo dyes are banned because, under reductive conditions such as contact with skin and sweat, they can split to release carcinogenic aromatic amines such as benzidine. The European Union's REACH regulation restricts azo colourants that can release any of 22 listed amines above 30 milligrams per kilogram in articles in contact with the skin, and India too prohibits such dyes under its environmental law. Other restricted substances include heavy metals, formaldehyde, chlorophenols and certain phthalates and flame retardants.
- Effluent treatment runs in stages: primary (screening, equalisation, neutralisation, coagulation-flocculation and settling), secondary (biological treatment such as activated sludge, which lowers BOD), and tertiary (membrane filtration including reverse osmosis, ozonation, activated carbon) to reach reuse quality. Zero liquid discharge recovers water and salt so that no effluent leaves the site; the knitwear cluster of Tiruppur in Tamil Nadu is the best-known Indian example.
- Eco-friendly textiles include organic cotton grown without synthetic pesticides and fertilisers, lyocell made in a closed solvent loop, recycled polyester from PET bottles, hemp and other low-input bast fibres, natural dyes, and low-impact reactive dyes and processes that save water and energy.
| Eco-label or mark | What it certifies |
|---|---|
| Oeko-Tex Standard 100 | Textiles tested for harmful substances, in four product classes; class I, for babies up to 3 years, is the strictest |
| GOTS (Global Organic Textile Standard) | Organic fibre content and environmental and social criteria through the whole processing chain |
| EU Ecolabel | Lower environmental impact across the life cycle |
| Eco Mark (India, 1991) | Environment-friendly products meeting BIS quality standards; the logo is an earthen pot |
4. Recent developments in textiles and apparel
- Nano textiles: nano-silver for antimicrobial action, nano titanium dioxide and zinc oxide for UV protection and self-cleaning, and nano-scale surface roughness for the superhydrophobic "lotus effect".
- Technical textiles are made for performance rather than appearance, conventionally grouped into twelve areas: agrotech, buildtech, clothtech, geotech, hometech, indutech, meditech, mobiltech, oekotech, packtech, protech and sporttech. India launched a National Technical Textiles Mission in 2020.
- Occupational clothing protects workers: flame-resistant aramids (meta-aramid) for firefighters and foundry workers, para-aramid and ultra-high-molecular-weight polyethylene for ballistic and cut protection, high-visibility garments with retro-reflective tape, chemical-protective and cleanroom garments, and medical personal protective equipment.
- Smart textiles sense and respond, with conductive yarns, embedded sensors and phase-change materials that store and release heat.
- Zero-waste design plans pattern pieces to interlock within the fabric width so that little or none is cut away; conventional cutting is commonly estimated to waste around 15 per cent of the fabric. Upcycling turns waste into a product of equal or higher value; recycling reprocesses it mechanically (shredding into fibre) or chemically (depolymerising polyester); downcycling yields lower-value products such as wipes and fillings. Together they belong to the idea of a circular economy for fashion.
5. Research methods III: types of research
Research is classified in several overlapping ways: by purpose (basic or applied), by method (quantitative or qualitative), by the kind of data (empirical or conceptual) and by time (historical, cross-sectional, longitudinal). The syllabus names the types that recur most often in Home Science, set out below. Fundamentals were covered in chapter 2 and designs in chapter 5; hypothesis testing follows in chapter 10.
| Type | What it does | Home Science example |
|---|---|---|
| Descriptive | Describes the state of affairs as it exists, without manipulating variables | Clothing expenditure pattern of urban working women |
| Survey | Collects standardised data from a large sample by questionnaire, schedule or interview, at one time (cross-sectional) or repeatedly (longitudinal) | District survey of household use of iodised salt |
| Historical | Reconstructs the past from primary sources (original documents, artefacts, eyewitnesses) and secondary sources, judged by external criticism (is the source genuine?) and internal criticism (is its content accurate and credible?) | Evolution of Baluchari motifs from museum textiles and weavers' records |
| Qualitative | Seeks meanings and experiences through words and observation, with small purposive samples; ethnography, phenomenology, grounded theory, case study | Lived experience of caregivers of children with autism |
| Quantitative | Measures variables numerically and analyses them statistically, aiming at generalisation | Relationship between maternal education and child's dietary diversity score |
| Analytical | Uses facts or information already available and analyses them critically to evaluate or explain | Analysis of NFHS data to explain state differences in anaemia |
| Action | Practitioners study and improve their own practice through cycles of planning, acting, observing and reflecting (Kurt Lewin, 1946) | An anganwadi supervisor trialling and refining a method to raise attendance at growth monitoring |
Key takeaways
- Textiles are conditioned at 20 °C and 65 per cent RH (ISO 139) and sampled at random, away from selvedges, before fibre, yarn, fabric and garment tests.
- GSM = specimen grams × 100 for a 100 cm² specimen; shrinkage per cent = (original − final) / original × 100.
- Grey scales run 1 to 5 and the blue wool light scale 1 to 8, higher always better; pilling is rated 1 (severe) to 5 (none).
- Banned azo dyes release carcinogenic amines; effluent is treated in primary, secondary and tertiary stages; Oeko-Tex Standard 100, GOTS, the EU Ecolabel and India's Eco Mark certify different claims.
- Technical textiles fall into twelve areas; zero-waste design, upcycling and recycling serve circular fashion; the research types are descriptive, survey, historical, qualitative, quantitative, analytical and action research.
Practice questions (10)
Attempt each one before opening the answer. Every explanation names the tempting wrong option as well as the right one, because that is where marks are lost.
A circular specimen of 100 cm² cut with a GSM cutter weighs 1.8 g. What is the fabric's GSM? Type the number.
Numerical answer — type the value.
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Answer: 180
100 cm² is 0.01 m², so GSM = 1.8 / 0.01 = 1.8 × 100 = 180 grams per square metre.A 50 cm benchmark marked on a fabric measures 47 cm after standard washing and drying. What is the shrinkage in per cent? Type the number.
Numerical answer — type the value.
Show answer
Answer: 6
Shrinkage = (50 − 47) / 50 × 100 = 3 / 50 × 100 = 6 per cent. Dividing by the final length instead (3 / 47) would overstate it slightly.In colourfastness testing, a grey-scale rating of 5 for staining means:
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Answer: B — No staining of the adjacent fabric
Grey scales run from 1, the greatest change or staining, to 5, no change or no staining. The blue wool light-fastness scale runs from 1 to 8, again with the highest number the best.Certain azo dyes are banned in textiles because they:
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Answer: B — Can release carcinogenic aromatic amines under reductive conditions
The ban targets azo dyes that can cleave to release listed amines such as benzidine, which are carcinogenic. Poor light fastness and cost are not grounds for a legal ban, and many permitted azo dyes are used on cotton.Which statements about eco-labels are correct? Select all that apply.
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Answer: A — India's Eco Mark was introduced in 1991 and uses an earthen pot as its logo; D — Oeko-Tex Standard 100 certifies that a textile is tested for harmful substances
Oeko-Tex Standard 100 is a harmful-substances test of the product, and the Eco Mark dates from 1991 with its earthen pot. Organic claims need a standard such as GOTS, and class I, for babies, is the strictest class, not the least.Firefighters' protective clothing is typically made from:
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Answer: D — Meta-aramid fibres
Meta-aramids are inherently flame-resistant and do not melt, so they protect against heat and flame. Acetate, untreated polyester and polypropylene are thermoplastic and melt onto the skin, which makes them dangerous near fire.Assertion (A): Zero-waste pattern cutting can remove most of the fabric waste of conventional garment cutting. Reason (R): Recycling shredded fabric back into fibre always yields fibre of the same quality as virgin fibre. Choose the correct option.
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Answer: C — A is true, but R is false
A is true: zero-waste design plans pieces to interlock within the fabric width, avoiding most of the offcuts of conventional cutting. R is false: mechanical recycling shortens fibres, so recycled fibre is usually of lower quality and often blended or downcycled.A researcher checks whether an old weaving pattern book attributed to a nineteenth-century weaver was really written in that period, by examining its paper, ink and handwriting. This is:
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Answer: C — External criticism in historical research
External criticism asks whether a source is genuine, that is authentic in origin, date and authorship, which is what examining paper, ink and handwriting establishes. Internal criticism then asks whether the content of a genuine source is accurate and credible.Which features characterise action research? Select all that apply.
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Answer: A — Its concept is associated with Kurt Lewin; B — It is carried out by practitioners to improve their own practice; C — It proceeds in cycles of planning, acting, observing and reflecting
Action research is practitioner-led, cyclical and associated with Kurt Lewin, who coined the term in the 1940s. Its aim is local improvement of practice; broad generalisation is the aim of large quantitative studies.A study uses published National Family Health Survey tables, without collecting new data, to explain why anaemia differs between states. It is best classed as:
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Answer: A — Analytical research
Analytical research critically analyses information already available to explain or evaluate, as this study does with NFHS tables. There is no practitioner cycle (action), no reconstruction of the past from sources (historical) and no manipulated treatment (experimental).