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A V-fastened tuft

A V-fastened tuft
A V-fastened tuft. A cut pile bound into its ground by V fastening, drawn in section. The pile end passes beneath 3 of the 6 ground picks and wraps 1 half-turn around them in all. The integrity criterion says the tuft is attached; how hard it is held is a different question with a different model behind it.

A cut pile bound into its ground by V fastening, drawn in section. The pile end passes beneath 3 of the 6 ground picks and wraps 1 half-turn around them in all. The integrity criterion says the tuft is attached; how hard it is held is a different question with a different model behind it.

10 essays call pile. The drawing above is what it returns with no arguments at all; every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the weave its essay argues about.

Where it is called

Changing this generator changes every one of these figures.

A V-fastened tuft. A cut pile bound into its ground by V fastening, drawn in section. The pile end passes beneath 3 of the 6 ground picks and wraps 1 half-turn around them in all. The integrity criterion says the tuft is attached; how hard it is held is a different question with a different model behind it. Compound and figured cloths

Pile is a third thread system

Velvet, corduroy, plush and carpet all carry threads that are not woven into the ground in the ordinary sense. Two of the three systems make a perfectly good matrix and the third is not in it — so the encoding this whole site rests on has nothing to say about the part of the fabric a hand actually touches.

What a tuft's wrap is worth at μ = 0.3. The two classical ways of binding a cut pile into its ground, with the holding force each provides as a multiple of the tension applied to the free end. The model is the capstan equation and the friction coefficient is measured rather than derived, so the ratio between the two matters and neither absolute number should be quoted alone. Compound and figured cloths

How a tuft is held

A V-fastened tuft and a W-fastened tuft are both attached, and the integrity criterion returns the same verdict for both. One of them is specified for hotel corridors and the other sheds. What separates them is not a topological property at all — it is an angle, and it needs a coefficient somebody has to measure.

Corduroy: floats of 6 ends, cut. 3 wales of an extra weft floating over 6 warp ends each, cut at their midpoints so that each half stands away from the ground. The pile height is half a float's length and nothing else decides it, so a finer sett at the same float count gives a shorter pile; the wale spacing is the float plus its binding ends. Compound and figured cloths

Corduroy is a cut float

An extra weft floats over some ends, a knife runs along the cloth, and each half of the float stands up. So the pile height is exactly half the float's length — which makes corduroy the one pile fabric whose surface is decided entirely by a quantity this site has been counting since its first essay.

Terry at a let-off of 5 to one. Towelling has two warp beams. The ground warp is held at ordinary tension; the pile warp is let off 5 times as fast, and the excess has nowhere to go but up. The loop height follows from the ratio and the pick spacing, and no float length appears in it. Compound and figured cloths

Terry needs two beams

A towel's pile is not woven longer. It is fed longer — from a second warp beam let off several times faster than the first — so the loop height follows from a ratio and a pick spacing, and the float length that decides a corduroy does not appear in it anywhere.

A leno and the open plain weave it is not. Two warp ends and the picks they hold. On the left the doup end passes under its partner between picks and comes up the other side; on the right it never crosses, which is an open plain weave at the same sett. The layer count under each panel is computed by the same criterion that decides every other draft, and it returns the same verdict for both. Compound and figured cloths

The criterion cannot see friction

This site's central check is exact, decidable in linear time, and structurally incapable of distinguishing a carpet from a fabric that sheds. That is not a defect to be repaired — a separation exists or it does not, and there is no margin in it — and the fancy weaves are precisely the constructions that live in the gap.

What holds a tuft in, in newtons. The withdrawal force of a V-fastened and a W-fastened tuft over the reported range of yarn-on-yarn friction, on a duck ground with 1.00 N in each pick. Each is the friction at the wraps, with each wrap's share dragged around every wrap between it and the pulled end — a capstan series rather than a single factor. W runs from 0.79 to 6.84 N and V from 0.15 to 0.41. Both are an order of magnitude below what a carpet is specified at, which is a finding about carpets rather than about the model. What the chart cannot show is the backing, which is where the rest of a tufted carpet's anchorage comes from. Compound and figured cloths

What holds a tuft in, in newtons

The pile ladder computed a tuft's anchorage as a capstan ratio and said, correctly, that a ratio was all it could offer. A ratio multiplies a tension and there was no tension anywhere on this site. There is one now — and the answer, put beside what a carpet is actually specified at, falls short by a factor of three.

How much too thick a round section is, and what reconciles it. For each cloth in this site's 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. Compound and figured cloths

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.

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. Compound and figured cloths

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.

A V-fastened tuft. A cut pile bound into its ground by V fastening, drawn in section. The pile end passes beneath 3 of the 6 ground picks and wraps 1 half-turn around them in all. The integrity criterion says the tuft is attached; how hard it is held is a different question with a different model behind it. Compound and figured cloths

A chenille is a yarn that is already a fabric

A chenille yarn is a woven gauze cut into strips. Every structural question this collection asks about cloth can be asked about it — does it hang together, how many systems has it, what holds the pile in — and the answers are the same answers one level down.

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. Compound and figured cloths

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.

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