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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. In 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.





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