Chapter XIV Tying-on, Drawing-in, and Weaving
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—
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.
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.
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.
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.
Fig. 37 Dobby Loom — By Permission of Messrs. Charles Parker, Sons & Co.
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
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.
Fig. 40. The New Way — By Permission of Messrs. Herbert Morris, Ltd
Notes
2 For structure of carpets, see pp. 394-114, Textile Design: Pure and Applied, by T. Woodhouse and T. Milne.