Textile Structure
how cloth is put together
Concept

Tuft — where it appears

A length of pile yarn standing proud of the ground fabric, bound into it at its base. What holds it in is friction along the wrap around the picks that bind it, and what brings it back up after it is crushed is the neighbouring tufts rather than anything in its fibres.

Named by 6 essays across one field — each of them below, with the objects they name alongside it.

How much too thick a round section is, and what reconciles it. For each cloth in the standard cloth table: the thickness a circular Peirce section predicts, the thickness a cloth of that construction measures, and the force per crossing that makes the flattened model reproduce the measurement. The over-prediction runs from 36% to 81%. The reconciling forces span a factor of 4.6 across a table whose counts span a factor of six, and every one of them is of the order of the contact force the cloth's own warp tension supplies — which is what makes this a model rather than eight fitted parameters. What the rows cannot show is that the thicknesses are trade figures for cloths of these constructions rather than measurements of these particular fabrics, so what is being read is an ordering.

The criterion gets a force

This site's integrity criterion decides exactly whether a draft describes one cloth, and has one standing limitation: it says a tuft bound under one pick and a tuft bound under three are both attached, and it is right, and one of those is a carpet while the other sheds. What separates them needs a normal force in a fabric that is not under tension — the number the rung that computed it recorded as unavailable, and the one a thickness gauge now supplies.

fancy · Integrity A 5.0 mm cotton pile standing and crushed. A pile tuft standing 5.0 mm proud and the same tuft pressed flat, which turns it through a right angle over its own length and so bends it to a radius of 3.18 mm. Its fibres are strained 0.187% — an order of magnitude below the smallest strain anybody has measured a recovery at, so this file declines to say what fraction comes back. The consequence is that a crushed carpet is not held down by its fibres: what keeps a pile flat is the tufts leaning on one another and the friction where they touch. Below 0.469 mm the fibre does enter its measured range, which is the difference between a carpet and a velvet and has nothing to do with what either is made of. What the drawing cannot show is the neighbouring tufts, which are the mechanism.

A crushed pile is not held down by its fibres

A carpet flattened under a foot has bent its tufts through a right angle, which sounds severe and is not: the fibres in a five-millimetre pile are strained under two tenths of a per cent, an order of magnitude below the smallest strain anybody has measured a recovery at. What holds a pile down is the tufts leaning on one another.

fancy · Pile Three kinds of surface, and only one of them starts open. The bearing curves of a 2/2 twill in sheeting, of a terry loop pile, and of a cut corduroy pile of 30 tex, over the first six per cent of a cloth's thickness. The woven curve opens as the square root of the depth and the loop pile's does the same, because a loop's top is a curved thread like any other. The cut pile does not open: it is a flat line at 5.2% of the plan, from a depth of nothing, because a blade severed every tuft in one pass and left every end in one plane. That is not a larger contact area, it is a different kind of contact area — one that does not vanish as the load goes to zero, which is a property no woven surface has.

A pile is the only surface with no crowns

Every other fabric touches on the tops of curved threads, so its contact vanishes as the load goes to zero and the pressure on what is touching rises without limit. A cut pile touches on flat ends left in one plane by a blade — so its contact is finite at no load at all, its pressure concentration is bounded, and it is the only fabric whose abrasion mass loss is an honest measure of its damage.

fancy · Pile Hair, nap and pile are one construction at three settings. 12 mm of sheeting at one pair of scales, carrying each of the three protruding surfaces a cloth can have — 50 pixels to the millimetre along the cloth and 29 off it. They are the same object, fibre standing off a cloth with a density, a length and a hold, and they differ by 9-fold in density and 4.8-fold in length. What actually separates them is the third line under each name: hairs are held by whatever the twist happened to leave, a nap by the float it was pulled from, and a pile by a W or a V through three picks. Only the last two were chosen. The pile's tufts are drawn in the float colour because that is what a woven pile is, and they are all one length because a blade cut them; the hairs and the nap are drawn as measured quantities and their lengths come from the population's own exponential. Each panel clips to the room it has, and the densest of the three is drawn at the model's own number rather than thinned.

Hair, nap and pile are one construction

There are three surfaces made of fibre standing off a cloth, and they have been arrived at from three different directions and in three different fields. They are the same object at three settings, and what separates them is not what they are but how much of them anybody decided.

fancy · Pile The fibre pieces in one cut tuft. A cut-pile tuft 3 mm tall on a 1 mm base, spun from a 25 mm staple, with a seeded sample of its fibre pieces drawn along the yarn: 16 pass under the binding pick and 2 lie wholly in one leg, between a fibre end and the cut tip. Across a whole pile the loose share is 21.9 per cent of the pieces and 7.0 per cent of the fibre. What the drawing cannot show is the twist, which holds the loose pieces by friction and is what they escape from.

A blade leaves loose fibre in every tuft

The account of hair, nap and pile ended on a clean claim: a blade collapses a population's length to one value, so a cut pile has no tail and nothing in it reaches past the rest. The tips are one length. The fibres are not. A tuft cut from staple yarn is a length of yarn with fibre ends scattered along it, and every fibre end that lands in a leg leaves a piece between it and the blade that nothing in the draft holds — a fifth of the pieces in an ordinary wool carpet, none in a filament one.

fancy · Pile Which loose pieces in a cut tuft are free at once. A cut-pile tuft 12 mm tall on a 2 mm base, spun from a 90 mm staple, with a seeded sample of its fibre pieces drawn along the yarn and the tip's untwisted run-out, 5.6 mm, shaded down each leg. 22 pieces pass under the binding pick; of the 9 that lie wholly in one leg, 3 lie wholly inside the run-out, where the twist presses on nothing, and are free at once; the other 6 reach down into twisted yarn and are held until wear opens the twist further. What the drawing cannot show is the run-out's edge, which is a fall in pressure rather than a line.

A cut pile sheds in two stages

Every cut tuft of staple yarn holds loose fibre pieces that nothing anchors but the twist, and at the tip the twist holds nothing: it runs out over a length the grip arithmetic already gives, five and a half millimetres in a wool carpet yarn. A loose piece lying wholly inside that run-out is free the day the carpet is laid; one reaching below it is held until walking opens the tip's twist. So the reservoir drains in two stages, and the pile height decides the split. A velvet sheds everything it will ever shed at once. A twelve-millimetre wool carpet sheds a fifth of its reservoir at once and four fifths later. A shag sheds almost nothing at first and fourteen per cent of its fibre eventually.

fancy · Pile

Named alongside it

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

PileCapstanAnchoragePillingStaple lengthVelvetAbrasionBearing curveBending rigidityCanopy criterionCanopy depthCloth thickness

All concepts