Weaving


=Preparatory to Weaving.= Yarn is wound on bobbins on the ring or mule

spinning frame. These bobbins are transferred to a machine called a

spooler where the yarn is re-wound on a spool preparatory to making

the warp.



A warp is formed by obtaining a definite number of threads (called

ends), usually in a precisely designed order of given length, and

allowing the ends to wind over a cylinder called a beam. I
order to

do this it is necessary to have spools placed in a definite position

in a frame called a creel.



Before the warp can be placed in the loom so as to weave or interlace

it with filling it must be sized. This is necessary for all single

twist warp yarns. Its primary object is to increase the strength and

smoothness of the thread, thus enabling it to withstand the strain and

friction due to the weaving operation. Other objects of sizing are the

increase of weight and bulk of the thread and the improvement and feel

of the cloth. The warp is usually sized by passing it over a roller

and through a bath of a starch mixture. The machine for sizing is

called a slasher. The warp is now ready to have the ends drawn in and

placed in the loom.



=Weaving.= Every woven piece of cloth is made up of two distinct

systems of threads, known as the warp and filling (weft), which are

interlaced with each other to form a fabric. The warp threads run

lengthways of the piece of cloth, and the filling runs across from

side to side. The manner in which the warp and filling threads

interlace with each other is known as the weave. When the word "end"

is used in connection with weaving it always signifies the warp

thread, while each filling thread is called a pick. The fineness of

the cloth is always expressed as so many picks and ends to the inch.

The fabrics produced by weaving are named by the manufacturers or

merchants who introduce them. Old fabrics are constantly appearing

under new names, usually with some slight modification to suit the

public taste.



=Weaving Processes.= In order to understand the different kinds of

weaves it is necessary to know, or at least to understand, the process

of forming cloth, called weaving. This is done in a machine called a

loom. The principal parts of a loom are the frame, the warp-beam, the

cloth-roll, the heddles, and their mounting, the reed. The warp-beam

is a wooden cylinder back of the loom on which the warp is wound. The

threads of the warp extend in parallel order from the warp-beam to the

front of the loom, and are attached to the cloth-roll. Each thread or

group of threads of the warp passes through an opening (eye) of a

heddle. The warp threads are separated by the heddles into two or more

groups, each controlled and automatically drawn up and down by the

motion of the heddles. In the case of small patterns the movement of

the heddles is controlled by "cams" which move up the heddles by means

of a frame called a harness; in larger patterns the heddles are

controlled by harness cords attached to a Jacquard machine. Every time

the harness (the heddles) moves up or down, an opening (shed) is made

between the threads of warp, through which the shuttle is thrown.



The filling thread is wound on a bobbin which is fastened in the

shuttle and which permits the yarn to unwind as it passes to and fro.

As fast as each filling thread is interlaced with warp it is pressed

close to the previous one by means of a reed which advances toward and

recedes from the cloth after each passage of the shuttle. This is done

to make the cloth firm. There are various movements on the loom for

controlling the tension of the warp, for drawing forward or taking up

the cloth as it is produced, and for stopping the loom in the case of

breakage of the warp thread or the running out of the filling thread.



Weaving may be performed by hand in hand-looms or by steam-power in

power-looms, but the arrangements for both are to a certain extent the

same. A great number of different kinds of power-looms are

manufactured for producing the various classes of textiles in use at

the present time. These looms are distinguished by the name of the

material which they are designed to weave, as the ribbon-loom,

blanket-loom, burlaps- and sacking-loom, plush-loom, double-cloth

loom, rug-loom, fancy cotton-loom, silk-loom, worsted-loom, etc.



Weaving is distinct from knitting, netting, looping, and braiding,

which are operations depending on the interlacing of a single thread,

or single set of threads, while weaving is done with two distinct and

separate sets of threads.



=Classes of Weave.= The character of the weave offers the best basis

for classification of woven goods. Nearly all the varieties of cloth

may be classified from the following weaves:



(1) Plain-weaving,

(2) Twill-weaving,

(3) Satin-weaving,

(4) Figure-weaving,

(5) Double-cloth-weaving,

(6) Pile-weaving,

(7) Gauze-weaving,

(8) Lappet-weaving.



=Plain or Homespun Weave.= Plain cloth is the simplest cloth that can

be woven. In this weave one series of threads (filling) crosses

another series (warp) at right angles, passing over one and under one

in regular order, thus forming a simple interlacement of the threads.

This combination makes a strong and firm cloth, but does not give a

close or a heavy fabric, as the threads do not lie as close and

compact as they do in other weaves. In plain cloth, if not fulled or

shrunk in the finish, the result is a fabric perforated with large or

small openings according to the size or twist of yarn used. If heavy

or coarse threads are used the perforations will be large; if finer

threads, the perforations will be smaller.



This weave is used in the production of sheeting, muslin, lawn,

gingham, broadcloth, taffeta, etc. In plain weaving it is possible to

produce stripes by the use of bands of colored warp, and checks where

both warp and weft are parti-colored. This weave is commonly used when

the cloth is intended to be ornamented with printed patterns. In

weaving cloth of only one color but one shuttle is used, while for the

production of checks, plaids, etc., two or more shuttles are required.



=Twill Weave.= A twill weave has diagonal lines across the cloth. In

this class of weaves the filling yarn or threads pass over 1 and under

2, or over 1 and under 3, 4, 5, or 6, or over 2 or 3 and under 1, 2,

3, or 4, or over 4 and under 4, 3, 6, etc. Each filling thread does

not pass under and over the same set of warp threads, as this would

not give the desired interlacings. Instead the order of interlacing

moves one thread to the right or left with each filling thread that is

woven. If there are the same number of threads to an inch in warp and

filling, twill lines will form an angle of 45 degrees; if the warps

are closer together than the filling, the angle will be steeper; if

the filling threads are closer together the lines will approach more

nearly the horizontal. Different effects are obtained in patterns by

variation in the sizes of the yarn and twist, by the use of heavy

threads to form cords, ribs, etc., and by the mixture of vari-colored

materials in the yarn. Often one form of twill-weave is combined with

another to produce a fancy twill-weave. The object of the

twill-weaving is to increase the bulk and strength of a fabric, or to

ornament it. The disposition of the threads permits the introduction

of more material into the cloth, and hence renders it heavier, and of

closer construction than in the case of plain-weaving.



=Satin Weaves.= The object of a satin weave is to distribute the

interlacings of the warp and filling in such a manner that no trace of

the diagonal (twill) line will be seen on the face of the cloth. In

weaving a satin design the filling thread is made to pass under 1 and

over 4, 7, 9, 11, or more if a larger plush satin is required. The

raising of the warp end to allow the filling to pass under is done in

such a way as to prevent twill lines from showing in the cloth. The

result is that practically all of the filling is on the face of the

cloth. This is called a filling-face satin weave. A warp-face satin

weave may be produced by reversing the order; in this case practically

all of the warp is brought to the face of the cloth. In this way a

worsted warp and a cotton filling might be woven so that practically

all of the warp would show on the cloth, and give it the appearance of

a worsted fabric. A number of classes of silk goods are made in this

way, with a silk filling covering a cotton warp.



This weave produces an even, close, smooth surface, capable of

reflecting the light to the best advantage, and having a lustrous

appearance which makes it resemble satin cloth. Satin cloth is made of

silk using a satin weave.



Satin weaves are used very largely in producing different styles of

cotton and silk fabrics, and are also frequently found in woolen

goods. They are more extensively used in the manufacture of damask and

table-covers than for any other class of goods. Satin stripes are

frequent in madras, shirtings, and fancy dress goods in connection

with plain and figured weaves.



=Figure Weaving.= To produce complicated and irregular patterns in the

loom a large number of different openings (sheds) must be made in the

warp, and to secure such a large number an attachment is placed on top

of the loom called a Jacquard apparatus. The Jacquard is merely an

apparatus for automatically selecting warp threads, by which each

separate one can be made to move independently of any of the others.

It is provided with weighted strings attached to each of the warp

threads. The weighted strings are controlled by wire needles which are

in turn controlled by perforated cards. Each motion of the loom

changes their position and allows some needles to go through the holes

in the cards, thus drawing up the warp, while others strike the card

and leave the warp down. In this way the perforations of the cards

determine the figure of the patterns. The Jacquard is chiefly used to

produce patterns of great width in which all or most of the threads

in the pattern move independently. For the weaving of elaborate

effects and flowing lines it is practically indispensable. All

elaborate designs are classed under the name of Jacquards.



=Double Cloth.= Double cloth is a descriptive term applied in weaving

to fabrics produced by combining two single cloths into one. Each one

of these single cloths is constructed with its own systems of warp and

filling, the combination being effected in the loom by interlacing

some of the warp or filling threads of one cloth into the other cloth

at certain intervals, thus fastening them securely together. The

reasons for making double-cloths are many. Sometimes it is done to

reduce the cost of heavy weight fabrics by using cheaper materials for

the cloth forming the back; again it may be to produce double-face

fabric; it allows great freedom for the formation of colored patterns

which may or may not correspond in pattern on both sides; it is the

basis of tubular weaving such as is practised for making pillow cases,

pockets, seamless grain bags, etc.; more frequently, the object is to

increase the bulk or strength of certain kinds of fabrics, such as

heavy overcoatings, cloakings, pile-fabrics, golf-cloth, rich silk,

etc.



=Pile Weave.= A pile weave is a general term under which are classed

numerous varieties of cloth woven with a pile surface, as plush,

velvet, velveteen, and carpeting of various kinds. Turkish towels are

an excellent illustration of pile weaving. A pile surface is a closely

set, elastic face covering various kinds of woolen, silk, and cotton

fabrics, and consists of threads standing close together, either in

the form of loops or as erect thread-ends sheared off smooth so as to

form a uniform and even surface. In the production of a pile fabric a

third thread is introduced into the weaving and formed into loops

usually by carrying it over the wires laid across the breadth of the

cloth. The wires are afterward drawn out, leaving the loops standing;

the loops may then be cut so as to form a cut pile, as in velvet and

plush, or they may be left in their original form as in Brussels

carpet and Turkish towels.



=Gauze Weaving.= In gauze weaving all the warp threads are not

parallel to each other, but are made to intertwist more or less among

themselves, thereby favoring the production of light, open fabrics, in

which many ornamental lace-like combinations can be obtained. Two sets

of warp threads are used, one being the ground warp and the other the

"douping," the latter performing the entwining process. Gauze is

especially characterized by its openness and yields the lightest and

strongest fabric with the least material. When gauze is combined with

plain weaving it is styled "leno." Gauze fabrics are designed for

women's summer gowns, flounces, window-curtains, etc.



=Lappet Weaving.= Lappet weaving, really a form of embroidery, is used

for producing small designs on cloth by means of needles placed in a

sliding-frame, the figures being stitched into the warp. Elaborate

figures are beyond the range of lappet weaving, but there are many

small effects that can be economically produced in this manner, such

as the detached spots in dotted swiss, and narrow and continuous

figures running more or less into stripes. This form of weaving

imitates embroidery and is used mainly on plain and gauze fabrics.



More

;