Choosing Fabric for 600 School Uniforms under Washing and Budget Limits
A co-educational school in Coimbatore needs 600 uniforms for students aged 11–14. The uniform consists of a shirt, a pleated pinafore for girls, and a sports T-shirt for all students. The school washes uniforms three times a week, expects two years of wear, and has a fabric budget of ₹250 per metre. The climate is hot and humid for most of the year. Four fabrics are quoted: A, 100% cotton plain weave, 120 GSM, 30s × 30s, 60 × 60, 5% shrinkage; B, 65/35 polyester–cotton plain weave, 140 GSM, 40s × 40s, 110 × 70, 1.5% shrinkage; C, 100% cotton single jersey, 160 GSM, 24s, 3% shrinkage; D, 100% polyester taffeta, 90 GSM, 2% shrinkage. The tailor proposes A for the shirt and the pinafore and C for the sports T-shirt. The school also needs a crisp collar that holds its shape after repeated washing.
1. Select the most suitable fabric for the shirt, the pleated pinafore and the sports T-shirt, and justify each choice using fabric structure and the stated constraints. Explain why D is unsuitable for the main garments.
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For the shirt, B is the safer choice under three washes a week and a two-year life: the 65/35 polyester–cotton plain weave has low shrinkage (1.5%), good abrasion resistance and reasonable breathability. A is more comfortable in a hot climate, but 5% shrinkage is high and it needs pre-shrinking or compacting; if the school insists on cotton, A should be purchased pre-shrunk and tested.
For the pleated pinafore, B is again preferable because a plain weave holds pleats and the polyester content improves shape retention and durability. A could be used only if the pleats are properly set and the fabric is pre-shrunk. C is a single jersey knit: it stretches and is comfortable, but it will not hold sharp pleats and is less abrasion-resistant at the seat and hem.
For the sports T-shirt, C is suitable: the jersey knit gives stretch, air permeability and freedom of movement. D, polyester taffeta, is a smooth filament plain weave with low air permeability, poor drape, a noisy hand and a hot feel; it is not appropriate for everyday school garments, especially in a humid climate.
2. For 600 shirts, the marker uses 1.8 m of fabric per shirt and 5% cutting waste. Calculate the metres to buy and the fabric cost at ₹220/m for A and ₹250/m for B. Which is cheaper, and what further information would you need before declaring B better?
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Fabric per shirt with waste = 1.8 × 1.05 = 1.89 m. For 600 shirts, 600 × 1.89 = 1,134 m.
Cost with A at ₹220/m = 1,134 × 220 = ₹2,49,480. Cost with B at ₹250/m = 1,134 × 250 = ₹2,83,500. A is cheaper by ₹34,020, or about 12%.
However, B may be better value over two years because its 1.5% shrinkage and higher abrasion resistance may reduce replacement and rejection. To decide, I would need the expected replacement rate, the cost of pre-shrinking A, the actual shrinkage after three washes, colour fastness and pilling performance, and whether the school values cotton comfort over easy care. The lowest purchase price is not automatically the lowest cost per wear.
3. The school needs a crisp collar. Explain how a nonwoven interlining should be specified and why a nonwoven is not appropriate for the main shirt body.
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The collar should use a fusible nonwoven interlining of about 30–40 GSM with a dot coating, chosen so that its shrinkage matches the shirt fabric. The specification should state the bonding temperature, pressure and time (typically around 140–150 °C, with a trial to confirm), and the bond strength should be tested after three washes. A suitable interlining gives the collar stiffness, shape retention and a clean edge without strike-through.
A nonwoven is not suitable for the main shirt body because it has low tensile and tear strength, poor drape, limited abrasion resistance and low breathability. It is a web of fibres bonded by heat, chemical or mechanical means, not a continuous yarn structure, so it cannot withstand the repeated washing and flexing of a shirt body. The main garment should remain a woven or knitted fabric; the nonwoven belongs only in small, stiffened components such as collars, cuffs and facings.