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8.2 Warp Pile

Introduction:1: Method of weaving2: Cutting (arrows)3: Development of pile weaves

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Introduction: Warp pile fabric contains three systems of warp and two systemsof weft: face end, back end and pile end; face pick and back pick,where face weave and back weave are called ground weave.

See Fig. 8.6:

Fig. 8.6

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The face and back fabrics are stitched on the loom bymeans of pile warp. The two fabrics are separated bycutting the pile threads.From Fig. 8.6 we can see a clear difference in warpcrimp between ground weave and pile warp, so a

separate weavers beam is necessary in weaving warppile.The representative fabric of warp pile is velvet.

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1. Method of weavingTwo ground cloths are produced with a certain space between them.The distance from face to back fabric determines the required heightof the pile. Pile ends interlace alternately with face and back picks.

According to different shedding and picking during the weaving, twocategories are classified as following :

A Fig. 8.7 sketch of warp pile weaving B

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1. Single shedding. See Fig. 8.7 (A) (show flash) Face cloth is formed by face ends and picks,

Back cloth is formed by back ends and picks2. Double shedding. See Fig. 8.7 (B) (show flash) Face and back cloths are formed simultaneously,

identically interlacing ends are drawn into two mailhealds.Face and back picks are inserted in pairs.

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2. Cutting (arrows)The two fabrics are separated by cutting the pilethreads in the middle during the weaving process.

Cutting takes place when the race is put back andthe pile ends are taut. Each cloth is to be woundon separately.F = faceB = back P = pile

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3. Development of pile

weaves1) Selection of the ground weave. For velvet, 1/1 plain is

preferable. Sometimes, 2/2 weft rib and 2/1 varied rib

are selected. The density of the piles, distribution of thepiles need to be considered during selection.

2) Determine the ways of binding type. V-type ispreferable compared with W-type.

3) Determine the ratio of the ground and pile warp4) A section diagram is helpful to the weave construction.

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Example 1: Construct the warp pile weave, the parametersare given below: V type binding Warp: 1 pile end1 face1 back1 pile1 face1back end

Weft: 1 face1 back pick. Ground: plain weave for face and back weaves.

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Answer to example 1:Determine the repeats

and draw the outlineDraw the longitudinal-section

Transfer the weave

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Notes to the key:

In the figure:a, b --- pile ends

Final weave:

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Example 2: get familiar with

the following warp piles:

V-type structure, one pile system

Warp: 1 pile ---- 1 face end ---- 1 back ---- 1 face ---- 1 back end for ground

Weft: 1 face pick ---- 1 back pick

Ground : plain weave for both face and back cloths

Pile: interlaces alternately with face and back picks

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Fast or W pile binding, one pile system

Warp : 1 pile end ---- 1 face --- 1 back --- 1 face --- 1 back end for groundWeft : 3 face picks --- 3 back picks

Ground : rib for face and back cloth

Pile :interlaces alternately with 3 face and 3 back picks.

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V-type binding, two pile systems

Warp: 1 face end A ---- 1 face ---- 1 back end1 pile end B ----1 face ---- 1 back end

Weft : 1 face ---- 1 back pick

Ground : plain weave for both face and back cloth

Pile: both pile ends interlace alternately with face and back picks

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Applications:Warp pile fabrics possess full piles. Soft hand,good elastic recovery, good crease resistance,thermal insulation and delicate colour. Widelyused for lady and children cloth, drapery, seatscovers, package cloth for some valuables.

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Home works:

According to the longitudinal-sections, indicate the requiredparameters and draw the weaves.

1)binding types; 2) arrangement; 3) ground weaves; 4)

weaves

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8.3 Terry pile

Introduction: These fabrics of such weaves are characterized

by formation of loops which are raised above thesurface of the fabric either on one or both sides.

The fabrics possess a relatively high level of wet

ability, hygroscopic, and soft handle. They areused for toweling as well as for bath mats, bedcovers and dress.

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The principles of loopsformation (show flash)

1. Special beating up Terry pile motion . short beating and fast beating

2. Special warp threads

The ground warp has a higher tension; and thepile warp have a loose tension.

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3. Special weaves and coordination

Resistance of the beating-up should beminimum.The pile warp is firmly held by ground weave.

After last beating-up, the last weft can notmove reversely.

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Fig. 8.9 Analysis of three picks terry pile

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First ,resistance of the beating-up:

See Fig. 8.9 (A), (B), (C). At (A), the ground ends interlace withweft two times; and at (B), (C) one time. So weave (A) has abigger resistance than (B) and (C). (B), (C) are preferable.Second, holding force:

(B), (C) have same gripping force to the pile warp. At (C), weft 1and 2, hold the pile warp; at (B) weft 2, 3 hold the pile warp. At(B), the loops can not be evenness. (C) is the best .Third, reverse motion of the last pick:

At the diagram (A) the weft 3 and next repeat weft 1 are in the same

fell. So after the reed goes back, the pick 3 will be moved reversely.

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At diagram (B), pick 3 can be moved, but it is not serious.The loop would change as the pick removes. Atdiagram (C), even the pick 3 can be removed, but thegripping force come from weft 1, 2, so it will not affectthe pile loop and the loop are kept constantly.

According to the analysis above, (C) is the best weave for3-picks terry fabric.

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Example 1: single sided pile

Fig.8.10 single sided terry pile

(A) (B) ( C)

Longitudinal-section

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Example 2: double sided pile

(A) (B) (C)

Double sided terry pile

Longitudinal-section

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Homework:

Describe the principles of terry pile formation.Main points:(1) fast beating and short beating.

(2) loose tension warp, higher tension warp.(3) Weave possess three requirements.