Part 1
[Page 1] THEORY OF SILK WEAVING
[Page 3] THEORY OF SILK WEAVING
A Treatise on the Construction and Application of Weaves, and the Decomposition and Calculation of Broad and Narrow, Plain, Novelty and Jacquard Silk Fabrics
Containing 95 Plates
_By_ ARNOLD WOLFENSBERGER
Graduate of the Textile Institute of Zurich, Switzerland
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Second Revised and Enlarged Edition
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NEW YORK
_Issued by_ THE AMERICAN SILK JOURNAL
CLIFFORD & LAWTON
_Publishers_
_1921_
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COPYRIGHT. 1921. by CLIFFORD & LAWTON
_All rights reserved_
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GROLIER CRAFT PRESS, Printers. 229 West Twenty-eighth Street, New York City
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[Page 5] PREFACE
The silk industry of America has of late years rapidly advanced to the front rank among the great textile industries of the world. It may indeed be proud of this position, to which that enterprising spirit and untiring energy peculiar to our nation, combined with our great technical and natural resources, has brought it.
That we are, on the other hand, not yet at the height of perfection we are also compelled to acknowledge, but if we consider the short space of time that the American industry has required for its development, as compared to the decades, almost centuries, to which some of the great European silk centers can look back, the fact is neither surprising nor discouraging.
While it must not be our aim to imitate or copy their ways, inasmuch as out conditions and circumstances are quite different from theirs, we may still profitably study their methods in order to overcome our deficiencies.
The greatest advantage which our competitors derive from such a long existence consists in having at their disposal a force of skilful, trained help. The manufacturers, appreciating the importance of this factor, make great efforts and pecuniary sacrifices to elevate and maintain the high standard of their industry.
For instance, they support textile schools and lecture courses, where young men can acquire a thorough technical education and equip themselves for a career of usefulness, thereby serving their own interests and at the same time furthering those of their chosen profession.
[Page 6] This beneficial influence cannot fail to exert itself from the standard of the higher employer down to that of the weaver, who would naturally take more pains and interest in his work than if he were a mere mechanical appendage to his loom in order to keep it in motion.
Very little has been done in his country for technical education as far as the silk industry is concerned, and it was on this special branch, that prompted the author to offer in the present little work a treatise on the theory of shaft weaving for broad silks and ribbons.
It is divided into three principal parts:
#1st. Drawing-in the warp in the harness. 2nd. The weaves and their application. 3rd. Decomposition or analysis of the cloth.#
To the foregoing there have been added in the revised and enlarged edition several additional parts covering the following: JACQUARD WEAVES, BOX LOOM WEAVES, including CREPES, and COST CALCULATIONS for plain and fancy weaves.
The subject while condensed, is made as clear and comprehensible as possible, and to many desirous of increasing their knowledge in this direction, this should prove a valuable help.
The author, through the medium of this work, hopes to win the approval and encouragement of the manufacturers, and will feel amply repaid should his efforts tend to develop a deeper interest in the "Queen of Textiles."
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[Page 7] THEORY OF SILK WEAVING
DRAWING-IN
With this term we designate the operation preceding the weaving, by which all the warp-threads are drawn through the heddles of the harness.
The order in which this is done varies according to the weave and the nature of the fabric to be produced; so we distinguish:
#Straight draws, Skip draws, Point draws, Section draws.#
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STRAIGHT DRAWS
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[Page 8] [Illustration: Fig. 2]
These form the simplest and most common method of drawing-in. We begin with the first heddle on the left side of the shaft _nearest to the warp-beam_, then take the first heddle of second shaft and so on until all the shafts the set contains are used in rotation. This completes one "draw," and this operation is repeated until all the warp-threads are taken up.
The method of making the shaft nearest to the warp-beam the first, is almost universal with the silk business and is technically called _drawing-in from back to front_.
The opposite, or drawing in from _front to rear_, is used occasionally, however, and in this case makes the first heddle on the left hand side of the front shaft No. 1.
The making out of the _Drawing-in Draft_, which must indicate the arrangement or the rotation in which the warp-threads are drawn in, can be done in various ways, of which we will mention the two most popular methods. The first is by using common designing paper, and indicating the rotation by dots. The horizonal rows of squares represent the shafts, the vertical rows the warp-threads. Fig. 1 shows four repeats of a straight draw on six harness marked out according to this idea. A second method is to use paper ruled horizontally, the lines representing the shafts; and to draw vertical lines for the warp-threads. The latter are made to stop on [Page 9] the lines bearing the number of the shafts into which the respective threads are to be drawn. Fig. 2 is such a draft, illustrating six repeats of a draw on four harness from "Front to Rear."
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SKIP DRAWS
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The draws coming under this heading are used very extensively in silk weaving, especially for fabrics requiring a heavy warp and a large number of shafts. Enter first the odd and then the even shafts. An 8 harness draw of this kind, of which three repeats are shown in Fig. 3, runs as follows: 1, 3, 5, 7, 2, 4, 6, 8.
Fig. 4 is a 12 harness draw of the same class.
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POINT DRAWS
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[Page 10] [Illustration: Fig. 6]
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[Page 11] Point draws are a combination of a regular straight draw from back to front and one from front to back, the first and the last shafts only being used once, while the rest receive two ends each in one repeat of the draw. Fig. 5 illustrates a regular point draw in 2 repeats on 10 shafts. It will be seen that 14 ends make a repeat; in fact, the number of warp-threads required for one draw will always be double the number of harness less 2, hence a 12 harness regular point draw will require 22 warp-threads for a repeat.
The drawing-in draft illustrated in Fig. 6 is a slight variation of the regular point draw; it consists, as will be seen, of a draw from back to front, and also a full one from front to back, there by causing a _double point_.
Another change from the regular point draw is illustrated in Figs. 7 and 8; this class may be called _Broken point draws_, because a new draw is begun before the other one is complete. Fig. 9 also comes in this class and represents a _zigzag draw_ on 10 harness.
The drawing-in drafts which we have described under the head of "Point draws," are used mostly to obtain the various pointed and zigzag effects.
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SECTION DRAWS
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[Page 12] [Illustration: Fig. 11]
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[Page 13] [Illustration: Fig. 15]
This division of drawing-in drafts is used extensively in silk manufacturing; for instance, in all fabrics having a ground warp and a binder warp, also in double-face goods, or where two different weaves are combined in one effect.
One or more threads are drawn on the first section, then one or more on a second and third, if the harness is divided in so many sets.
The following examples will illustrate the principle of these draws.
In Fig. 10, shafts 1, 2, 3, 4 from the first set, shafts 5 and 6 the second, 8 threads are drawn straight on the first, then 2 on the second section.
Fig. 11, first set shafts 1 to 6 inclusive, second set shafts 7 and 8.
Fig. 12 is drawn end and end on two sections having 8 shafts each.
Figs. 13, 14 and 15, while not strictly belonging to the class of section draws, may, however, be considered under this heading. The idea is to draw a certain number of ends in one part of the harness and another group in another part, be it straight, point or skip, which will cause the effect on the cloth to be accordingly transposed or broken up.
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THE WEAVES AND THEIR CONSTRUCTION
In any woven fabric we distinguish two systems of threads, the _Warp or Chain_, running lengthways in the cloth, and the _Filling or Weft_, crossing the former at right angles.
This crossing or interlacing consists of every individual warp-thread being placed alternately under and over one or more threads of the filling system. The arrangement of this interlacing is technically called the _Weave_, and the variety in which the points of crossing can be distributed is practically endless.
It is principally the weave that lends to a fabric its character, influenced, of course, by the material used, the size and tension of the threads and the combination of the colors.
The weaves are divided into three main classes: _the Foundation weaves_. In the silk business they are known under the following names:
#The Taffeta Weave, The Serge Weave, The Satin Weave.#
In the foundation weaves each thread effects only one crossing in one repeat of the weave, and the points of interlacing occur in a given rotation. A repeat in the foundation weaves comprises the same number of warp-threads as of _picks_ or filling threads, and if this number is 8, for [Page 16] instance, the weave is called an 8-shaft or an 8-harness weave. In marking out a weave, the warp-threads are represented by vertical lines, the filling by horizontal ones, or in each case by the space between these lines. The places where a warp-thread lies over the filling are marked with paint or simply with a cross. In a similar manner we mark out the _chain draft_, which indicates the rotation in which the shafts are raised.
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[Page 17] THE TAFFETA WEAVE
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[Page 18] This is the simplest and oldest method of interlacing. The odd numbers of warp-threads cross the even numbers after every pick; hence of two warp-threads one will always go over the first pick and under the second, and the other end under the first and over the second pick. Taffeta cloth, therefore, has the same appearance on both sides, and in cotton and wool weaving this weave is technically--and properly indeed--called the _Plain Weave_. It has the smallest repeat, 2 warp-threads and 2 picks, and the exchanging of warp and filling is the most frequent possible. The cloth thus produced is firmer and stronger than that obtained with any other weave.
Fig. 16 is a taffeta on 4 shafts straight draw, the draft executed in the manner which we have already mentioned in explaining the drawing-in drafts.
Fig. 17 on common designing paper, illustrates a taffeta made on 8-harness, skip draw.
Be it mentioned that the drawing-in draft and the chain draft will be added throughout this work, the former over the weave to correspond with the respective warp-threads, the latter to the right of the drawing-in draft.
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[Page 19] GROS DE TOURS WEAVES
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In this weave the working of the warp is the same as in taffeta, except that instead of one pick, two or more are inserted in the same shed. It is mostly used in selvedges, where it serves to give more firmness to the edge of an otherwise loosely woven cloth, and prevents the weaving ahead of the edge in a tight weave. Gros de Tours is sometimes used, especially when cotton or wool filling is employed, with a view to lay two picks nicely side by side, whereas a thread entered two ply with the taffeta weave will always receive some twist, which may disturb the perfect evenness of the fabric.
Fig. 18 is a Gros de Tours with two picks on four harness straight through.
Fig. 19 illustrates this weave with three picks drawn end and end on two sections of four shafts each.
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[Page 20] SERGE or TWILL WEAVES
While the taffeta weave produces either an entirely smooth fabric, or one with a distinct transverse rib as in gros-grain, the twill weave forms diagonal lines on the cloth, running either from left to right or from right to left.
To make a twill, not less than three ends and three picks are required, of which each thread floats over two of the other system and interlaces with the third. The rotation of the interlacing is always consecutive, that is it moves with each succeeding pick one thread to the right (or to the left if the lines are to run in that direction). If warp and filling have the same texture, that is the same number of threads in a given space, the twill lines will form an angle of 45°; if the warp stands closer than the filling, the incline will be steeper, and in the opposite case the angle will approach more the horizontal.
The weaves can be expressed in numbers, for instance: the 3-end twill warp effect would be marked 2-1, which indicates that each warp-thread goes over two and under one pick.
Twill weaves are called _evensided_ when the arrangement of "warp up" and "filling up" are evenly balanced, and _unevensided_ if either warp or filling predominate on the face of the fabric; the latter class is therefore subdivided in _Warp effects_ and _Filling effects_.
In the following a number of serge weaves are illustrated, the French designations being added in some cases, as they are still extensively used in the trade.
[Page 21] * * * * *
FILLING EFFECTS
_Satin de Lyon,_ 2-1.
On 6 harness straight through.
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_Levantine,_ 3-1<h/5>
On 8 shafts skip draw.
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[Page 22] _Polonaise,_ 5-1
On 12 harness skip draw.
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_Serge grosse côte,_ 7-1
On 8 shafts straight through.
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[Page 23] _Serge remaine,_ 6-2
On 8 shafts skip draw.
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_Serge,_ 5-1, 1-1.
On 8 shafts skip draw.
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[Page 24] _Serge,_ 4-2, 1-1, 1-1.
On 10 harness straight through.
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_Serge,_ 7-1, 1-1, 1-1, 1-1, 1-1.
On 16 shafts skip draw.
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[Page 25] WARP EFFECTS
_Levantine,_ 3-1.
On 4 shafts straight through.
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_Serge,_ 5-1, 1-1.
On 8 shafts skip draw.
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[Page 26] EVENSIDED TWILLS
_Surah,_ 2-2
On 4 shafts straight through.
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_Croise,_ 3-3, 2-2, 1-1.
On 12 shafts straight through.
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[Page 27] _Serge,_ 7-7, 1-1, 1-1, 1-1
On 20 shafts skip draw.
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POINTED TWILLS
in the direction of the filling and also of the warp.
On 4 shafts point draw, weave 3-1.
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[Page 28] [Illustration: Fig. 34]
On 6 shafts point draw, drawn as follows:
Eighteen ends from back to front and 4 ends from front to rear, weave 5-1.
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On 8 shafts pointed draw, weave 5-1, 1-1.
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[Page 29] [Illustration: Fig. 36]
On 10 shafts, with weave 3-3, drawn as follows:
7 threads from back to front. 3 " " front to rear. 6 " " back to front. 2 " " front to rear.
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On 6 shafts straight draw, pointed weave 5-1.
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[Page 30] [Illustration: Fig. 38]
On 8 shafts straight through, pointed weave 5-1, 1-1.
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_Broken pointed twill_, on 8 harness.
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[Page 31] [Illustration: Fig. 40]
On 6 shafts point draw, pointed weave 5-1.
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On 8 shafts point draw, pointed weave 5-1, 1-1.
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[Page 32] [Illustration: Fig. 42]
_Fancy twill_, on 16 shafts straight draw.
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SATIN WEAVES
The distinct diagonal lines which characterize the class of weaves explained in the previous chapter are absent in the satin weaves; and while the interlacing in the former is done in a strictly consecutive order, we endeavor to scatter the points of stitching in the latter as much as possible, in order to create an entirely smooth and brilliant surface on [Page 33] the cloth.
In all satins the number of ends in a repeat is the same in warp and filling.
The lowest repeat of a regular satin comprises five threads of each system, and the interlacing is done in the following order:
The 1st pick with the 1st warp-thread " 2d " " 3d " " 3d " " 5th " " 4th " " 2d " " 5th " " 4th "
Fig. 43 illustrates this weave. An examination of the rotation, as given above, will show that every warp-thread intersects two picks apart from its neighbor. The number "2" is in this case what is technically known as the _counter_, that is the number which indicates the points of interlacing by adding it to number 1 and continuing so until all the warp-threads are taken up.
The following is the rule to find the counter for any regular satin:
Divide the number of harness into two parts, which must neither be equal nor have a common divisor. Any of these two numbers can be used for counting off, but usually the smaller one is taken. According to this rule we obtain a regular satin
On 5 harness with counter 2 " 7 " " 2 or 3 " 8 " " 3 " 9 " " 2 or 4 " 10 " " 3 " 11 " " 2, 3, 4 or 5 " 12 " " 5 " 13 " " 2, 3, 4, 5 or 6 " 14 " " 3 or 5 " 15 " " 2, 4 or 7 " 16 " " 3, 5 or 7.
[Page 34] The 4 harness broken twill, Fig. 53, is sometimes classed among the satins.
The 6 harness satin, Fig. 54, is irregular; as a counter cannot be derived from number 6 by the given rule. The rotation generally used is 1, 3, 6, 4, 2, 5.
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Regular Satins
_5 harness Satin, "Satin de Chine."_
Straight draw, counter 2.
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_7 harness Satin, "Satin Merveilleux."_
Skip draw, counter 2.
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[Page 35] _7 harness satin_
Straight draw, counter 3.
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_8 harness satin "Duchese"_
Skip draw, counter 3.
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[Page 36] _9 harness satin_
Straight draw, counter 4.
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_10 harness satin_
Straight draw, counter 3.
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[Page 37] _11 harness satin_
Skip draw, counter 5.
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_12 harness satin_
Skip draw, counter 5.
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[Page 38] _16 harness satin_
On 2 sections of 8 shafts each, drawn end and end, counter 7.
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[Page 39] _8 harness satin, warp effect._
Straight draw, counter 3.
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IRREGULAR SATINS
_Satin Turc._
On 4 shafts straight through.
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[Page 40] _Satin à la Reine_
On 6 shafts straight draw.
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[Page 41] * * * * *
DERIVATIVE WEAVES
#1. From the Taffeta#
_Royale_ is a modification of the regular Gros de Tours, inasmuch as the rib line, which in the latter runs straight across the cloth, is broken off after a given number of warp-threads. These groups, which may comprise 8, 12 or more threads, will interlace each one pick higher than the preceding one.
_Royale of 8 ends_
On 2 sections of 4 shafts each.
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_Velours Ottoman or Faille française._
In order to obtain a broader rib than that of Gros de Tours, and at the same time to lend firmness to the fabric, we add to the ground warp, which forms the ribs, another or binder warp, which works continually taffeta, [Page 42] while the ground warp changes only every 3 or 4 picks for the rib.
_Faille française._
4 ends of ground on the first section of 8 shafts, skip draw. 1 " binder " second " 2 "
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_Velours Ottoman without a Binder-warp._
In this weave, of which Fig. 57 illustrates a specimen, comprising 8 warp-threads and 32 picks in a repeat, the rib contains 4 picks. Of the 8 warp-threads, 3 float over and 3 under the rib, while the 2 others bind taffeta, which latter function is executed by 2 other threads in the next rib.
[Page 43] [Illustration: Fig. 57]
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2. From the Twills
One variety is obtained by interlacing the warp-threads alternately one or more picks behind, and then a number of picks ahead of their respective neighbors; so the complete arrangement of the points of binding in a repeat will generally form two parallel diagonal lines. This will cause the twill lines to appear less pronounced than is the case in the regular twill, and the character of the fabric approaches more that of the satin.
[Page 44] [Illustration: Fig. 58]
_Satin Sergé._
On 8 shafts, straight draw.
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_Côte Satinée._
On 16 harness, skip draw.
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_Rhadzimir-Surah 2-2._ After a certain number of picks of the regular surah all the warp-threads are crossed in two's thereby causing a sort of a rib or cut line across the fabric.
[Page 45] _Rhadzimir of 4 picks._
On 8 shafts, straight draw.
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_Rhadzimir of 6 picks._
On 8 shafts, straight draw.
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[Page 46] 3. From the Satin Weave
_Satin Soleil_ shows a satin-like surface with a cross line appearance. Fig. 62 illustrates it as made on 8 shafts, straight draw.
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