Textile Structure
how cloth is put together
Concept

Regain — where it appears

The mass of water a fibre holds at standard conditions as a fraction of its dry mass. It is not the same quantity as swelling and is not proportional to it, and it matters here because every yarn count is quoted at it.

Named by 4 essays across 2 fields — each of them below, with the objects they name alongside it.

A cotton fibre dry and wet. One cotton fibre in its dry state and saturated with water, both drawn at the same scale in both directions. It is 20% wider and 1.2% longer, so its cross-sectional area rises by 44% if the section stays similar to itself. The length difference is drawn and is nearly invisible, which is the point: a swelling that were the same in both directions would make a cloth bigger and change nothing about its structure, and this one changes every ratio of a diameter to a spacing in the cloth. What the drawing cannot show is the section: a cotton fibre is not a cylinder, and the directly measured area swelling of 40% to 42% does not agree with the square of the width change, which is a fact about the fibre.

What water does to a thread

A cotton fibre in water is a fifth wider and a hundredth longer. If it grew equally in both directions a wet cloth would simply be a bigger cloth and nothing structural would follow; because it does not, every ratio of a diameter to a spacing in a cloth moves, and they all move the same way.

cloth · Water Cotton and viscose in every column this site carries. The two cellulosic fibres compared across every constant on this site. Both are cellulose at 1.52 g/cm³, both are given a modulus of 8 GPa and a fineness of 1.7 dtex, so a 20 tex yarn of either has the same diameter to the last figure — and therefore the same crimp, the same cover, the same jamming sett and the same bending bracket. Every geometric result on this site is the same number for the two fibres. Water separates them twice: viscose swells 1.75 times as far across and loses half its strength where cotton gains a tenth. What the table cannot show is why, which is a question about how cellulose is arranged inside a fibre and is not in this collection.

Water tells two fibres apart

Cotton and viscose are the same material by every constant this collection carries. Same density, same modulus, same fineness, so the same diameter at every count and the same crimp, cover, jamming sett and bending bracket. A wash separates them by a factor of two, and it is the only thing here that can.

mechanics · Yarn stiffness Where a wet cloth keeps its water. For four cloths of this collection's own table, the share of the water a saturated cloth holds that sits inside the fibre as regain, between the fibres inside the yarn, and between the yarns in the cloth's own holes. muslin at 99 grams a square metre holds 183 per cent of its own weight, 4.6 per cent of it in the fibre; sheeting at 155 grams a square metre holds 113 per cent of its own weight, 7.5 per cent of it in the fibre; poplin at 100 grams a square metre holds 165 per cent of its own weight, 5.2 per cent of it in the fibre; duck at 207 grams a square metre holds 139 per cent of its own weight, 6.1 per cent of it in the fibre. The fibre's own water — the property cotton is sold on — is a twentieth to a thirteenth of the total, and the other nineteen twentieths are geometry. What the bars cannot show is the hair layer, which holds water outside all three of these and which this arithmetic has no place for.

A cotton's own water is a twentieth of what a cloth holds

A wet cloth keeps water in three places and only one of them is the fibre. A sheeting saturated holds 113 per cent of its own dry weight: 7.5 per cent of that inside the cotton as regain, 39 per cent in the channels between the fibres of its yarns, and 54 per cent in the holes four threads bound. The same construction in polyester, whose regain is a fortieth of cotton's, holds 105 per cent — an eight-point difference from a fortyfold one, because absorbency is a geometry with a fibre in it rather than a fibre with a geometry round it.

cloth · Water What a spin leaves in a cotton load, against the drum's speed. The water left in a 68 mm load of cotton sheeting in a drum of 250 mm radius, as a share of the load's dry weight, against the spin speed. Read with the fibre holding its swollen water, the spin leaves 51% at 1,000 rpm and 41% at 1,400, and no speed takes it below 30%, the volume the fibre grew by. Read with the fibre holding only its regain, as the earlier account of a wet cloth did, the same spin leaves 16% at 1,400 and the floor is 8.5%. What the chart cannot show is the water a drained channel keeps as a film and as rings at the fibre contacts, which the model takes as nothing and which lifts every point on both curves.

A spin leaves the water a fibre swelled by

A washing machine's spin is a centrifuge, and it drains a cloth in the order its pores give up water: the holes between the yarns at a few g, the channels inside the yarns only far enough from the drum's wall, and the water inside the fibre never. That last reservoir is not the regain. A soaked cotton fibre holds the volume it swelled by — 30 per cent of its dry weight, three and a half times the regain — and it is the floor under every spin speed there is.

cloth · Water

Named alongside it

The objects these essays reach for when they reach for this one.

MoisturePacking factorSwellingFibre diameterOpen areaTwo pore systemsViscoseWaterAnisotropyBending rigidityBracketCover factor

All concepts