If all the threads of the newly-dressed warp can be tied on to the
ends of the warp which has been woven, it is only necessary, when
the tying-on process is completed, to rotate the loom beam slowly,
and simultaneously to draw forward the threads until all the knots
have passed through the cambs and the reed, and sufficiently far
forward to be clear of the latter when it approaches its full forward,
or beating up, position during the operation of weaving.
If, on the other hand, the threads of the newly-dressed, or
newly-beamed, warp had to be drawn-in and reeded, these operations
would be performed in the drawing-in and reeding department, and,
when completed, the loom beam with its attached warp threads, cambs
and reed, would be taken bodily to the loom where the "tenter,"
"tackler" or "tuner" adjusts all the parts preparatory to the actual
operation of weaving. The latter work is often termed "gaiting a web."
There is a great similarity in many of the operations of weaving the
simpler types of cloth, although there may be a considerable
difference in the appearance of the cloths themselves. In nearly all
the various branches of the textile industry the bulk of the work in
the weaving departments of such branches consists of the manufacture
of comparatively simple fabrics. Thus, in the jute industry, there
are four distinct types of cloth which predominate over all others;
these types are known respectively as hessian, bagging, tarpauling
and sacking. In addition to these main types, there are several
other simple types the structure of which is identical with one or
other of the above four; while finally there are the more elaborate
types of cloth which are embodied in the various structures of
carpets and the like.
It is obviously impossible to discuss the various makes in a work of
this kind; the commoner types are described in _Jute and Linen
Weaving Calculations and Structure of Fabrics_; and the more
elaborate ones, as well as several types of simple ones, appear in
_Textile Design: Pure and Applied_, both by T. Woodhouse and T.
Milne.
Six distinct types of jute fabrics are illustrated in Fig. 32. The
technical characteristics of each are as follows--
[Illustration: FIG. 32 SIX DISTINCT KINDS OF TYPICAL JUTE FABRICS]
H.--An ordinary "HESSIAN" cloth made from comparatively fine single
warp and single weft, and the threads interlaced in the simplest
order, termed "plain weave." A wide range of cloths is made from the
scrims or net-like fabrics to others more closely woven than that
illustrated.
B.--A "BAGGING" made from comparatively fine single warp arranged in
pairs and then termed "double warp." The weft is thick, and the
weave is also plain.
T.--A "TARPAULING" made from yarns similar to those in bagging,
although there is a much wider range in the thickness of the weft.
It is a much finer cloth than the typical bagging, but otherwise the
structures are identical.
S.--A striped "SACKING" made from comparatively fine warp yarns,
usually double as in bagging, but occasionally single, with medium
or thick weft interwoven in 3-leaf or 4-leaf twill order. The weaves
are shown in Fig. 33.
C.--One type of "CARPET" cloth made exclusively from two-ply or
two-fold coloured warp yarns, and thick black single weft yarns. The
threads and picks are interwoven in two up, two down twill, directed
to right and then to left, and thus forming a herring-bone pattern,
or arrow-head pattern.
P.-An uncut pile fabric known as "BRUSSELLETTE." The figuring warp
is composed of dyed and printed yarns mixed to form an indefinite
pattern, and works in conjunction with a ground warp and weft. The
weave is again plain, although the structure of the fabric is quite
different from the other plain cloths illustrated. The cloth is
reversible, the two sides being similar structure but differing
slightly in colour ornamentation.
As already indicated, there are several degrees of fineness or
coarseness in all the groups, particularly in the types marked H, B,
T and S. The structure or weave in all varieties of any one group is
constant and as stated.
All the weaves are illustrated in the usual technical manner in Fig.
33, and the relation between the simplest of these weaves and the
yarns of the cloth is illustrated in Fig. 34. In Fig. 33, the unit
weaves in A, B, C, D, E and F are shown in solid squares, while the
repetitions of the units in each case are represented by the dots.
[Illustration: FIG. 33 POINT-PAPER DESIGNS SHOWING WEAVERS FOR
VARIOUS CLOTHS]
[Illustration: FIG. 34 DIAGRAMMATIC VIEWS OF THE STRUCTURE OF PLAIN
CLOTH]
A is the plain weave, 16 units shown, and used for fabrics H and P,
Fig. 32.
B is the double warp plain wave, 8 units shown, and shows the method
of interlacing the yarns h patterns B and T, Fig. 32. When the warp
is made double as indicated in weave _B_, the effect in the cloth
can be produced by using the mechanical arrangements employed for
weave _A_. Hence, the cloths _H_, _B_ and _T_ can be woven without
any mechanical alteration in the loom.
_C_ is the 3-leaf double warp sacking weave and shows 4 units;
since each pair of vertical rows of small squares consists of two
identical single rows, they may be represented as at _D_. The actual
structure of the cloth _S_ in Fig. 32 is represented on design paper
at _C_, Fig. 33.
_D_ is the single warp 3-leaf sacking weave, 4 units shown, but
the mechanical parts for weaving both _C_ and _D_ remain constant.
_E_ is the double warp 4-leaf sacking, 2 units shown, while
_F_ is the single warp 4-leaf sacking, 4 units shown.
The patterns or cloths for _E_ and _F_ are not illustrated.
_G_ is a "herring-bone" design on 24 threads and 4 picks, two
units shown. It is typical of the pattern represented at _C_, Fig. 32,
and involves the use of 4 leaves in the loom.
The solid squares in weave _A_, Fig. 33, are reproduced in the
left-hand bottom corner of Fig. 34. A diagrammatic plan of a plain
cloth produced by this simple order of interlacing is exhibited in
the upper part by four shaded threads of warp and four black picks
of weft (the difference is for distinction only). The left-hand
intersection shows one thread interweaving with all the four picks,
while the bottom intersection shows all the four threads
interweaving with one pick. The two arrows from the weave or design
to the thread and pick respectively show the connection, and it will
be seen that a mark (solid) on the design represents a warp thread
on the surface of the cloth, while a blank square represents a weft
shot on the surface, and _vice versa_.
A weaving shed full of various types of looms, and all driven by
belts from an overhead shaft, is illustrated in Fig. 35. The loom in
the foreground is weaving a 3-leaf sacking similar to that
illustrated at _S_, Fig. 32. while the appearance of a full weaver's
warp beam is shown distinctly in the second loom in Fig. 35. There
are hundreds of looms in this modern weaving shed.
[Illustration: FIG. 35 WEAVING SHED WITH BELT-DRIVEN LOOMS]
During the operation of weaving, the shuttle, in which is placed a
cop of weft, similar to that on the cop winding machine in Fig. 25,
and with the end of the weft threaded through the eye of the shuttle,
is driven alternately from side to side of the cloth through the
opening or "shed" formed by two layers of the warp. The positions of
the threads in these two layers are represented by the designs, see
Fig. 33, and while one layer occupies a high position in the loom
the other layer occupies a low position. The threads of the warp are
placed in these two positions by the leaves of the camb (termed
healds and also gears in other districts) and it is between these
two layers that the shuttle passes, forms a selvage at the edge each
time it makes a journey across, and leaves a trail or length of weft
each journey. The support or lay upon which the shuttle travels
moves back to provide room for the shuttle to pass between the two
layers of threads, and after the shuttle reaches the end of each
journey, the lay with the reed comes forward again, and thus pushes
successively the shots of weft into close proximity with the ones
which preceded.
[Illustration: FIG. 36 LOOMS DRIVEN WITH INDIVIDUAL MOTORS _By
permission of The English Electric Co., Ltd._]
The order of lifting and depressing the threads of the warp is, as
already stated, demonstrated on the design paper in Fig. 33, and the
selected order determines, in the simplest cases, the pattern on the
surface of the cloth when the warp and weft yarns are of the same
colour. A great diversity of pattern can be obtained by the method
of interlacing the two sets of yarn, and a still greater variety of
pattern is possible when differently-coloured threads are added to
the mode of interlacing.
To illustrate the contrast in the general appearance of a weaving
shed in which all the looms are driven by belts from overhead
shafting as in Fig. 35, and in a similar shed in which all the looms
are individually driven by small motors made by the English Electric
Co., Ltd. we introduce Fig. 36. This particular illustration shows
cotton weaving shed, but precisely the same principle of driving is
being adopted in many jute factories.
A great variety of carpet patterns of a similar nature to that
illustrated at C, Fig. 32, can be woven in looms such as those
illustrated in Fig. 35; indeed, far more elaborate patterns than
that mentioned and illustrated are capable of being produced in
these comparatively simple looms. When, however, more than 4 leaves
are required for the weaving of a pattern, a dobby loom, of the
nature of that shown in Fig. 37, is employed; this machine is made
by Messrs. Charles Parker, Sons & Co., Ltd., Dundee. The dobby itself,
or the apparatus which lifts the leaves according to the
requirements of the design, is fixed on the upper part of the
frame-work, and is designed to control 12 leaves, that is, it
operates 12 leaves, each of which lifts differently from the others.
[Illustration: _By permission of Messrs. Charles Parker, Sons & Co_.
FIG. 37 DOBBY LOOM]
A considerable quantity of Wilton and Brussels carpets is made from
jute yarns, and Fig. 38 illustrates a loom at work on this
particular branch of the trade. The different colours of warp for
forming the pattern me from small bobbins in the five frames at the
back of the loom (hence the term 5-frame Brussels or Wilton carpet)
and the ends passed through "mail eyes" and then through the reed.
The design is cut on the three sets of cards suspended in the
cradles in the front of the loom, and these cards operate on the
needles of the jacquard machine to raise those colours of yarn which
e necessary to produce the colour effect in the cloth t correspond
with the colour effect on the design paper made by the designer.
This machine weaves the actual Brussels and Wilton fabrics, and
these cloths are quite different from that illustrated at _P_, Fig.
32. In both fabrics, however, ground or foundation warps are
required. It need hardly be said that there is a considerable
difference between the two types of cloth, as well as between the
designs and the looms in which they are woven.[2]
[Footnote 2: For structure of carpets, _see_ pp. 394-114, _Textile
Design: Pure and Applied_, by T. Woodhouse and T. Milne.]
[Illustration: FIG. 38 BRUSSELS CARPET JACQUARD LOOM]
In the weaving department there are heavy warp beams to be placed in
the looms, and in the finishing department there are often heavy
rolls of cloth to be conveyed from the machines to the despatch room.
Accidents often happen when these heavy packages, especially the
warp beams, are being placed in position. In order to minimize the
danger to workpeople and to execute the work more quickly and with
fewer hands, some firms have installed Overhead Runway Systems, with
suitable Lifting Gear, by means of which the warp beams are run from
the dressing and drawing-in departments direct to the looms, and
then lowered quickly and safely into the bearings. Such means of
transport are exceedingly valuable where the looms are set close to
each other and where wide beams are employed; indeed, they are
valuable for all conditions, and are used for conveying cloth direct
from the looms as well as warp beams to the looms. Fig. 39 shows the
old wasteful and slow method of transferring warp beams from place
to place, while Fig. 40 illustrates the modern and efficient method.
The latter figure illustrates one kind of apparatus, supplied by
Messrs. Herbert Morris, Ltd., Loughborough, for this important
branch of the industry.
[Illustration: FIG. 39. THE OLD WAY]
[Illustration: FIG. 40. THE NEW WAY _By permission of Messrs.
Herbert Morris, Ltd_.]