_Three Leaf Twill or Satin Face Woven in Conjunction with Plain
Back—Position of Back Rolls in Relation to Harness Shed—Use of Four Leaf
Twill—Filling Fancy Effects and Stitch Figures—Interchanging Figure and
Face_
Turning our attention from plain webs to combination weaves, we will take
up what is popularly known as the three-leaf twill, or satin face, woven
in conjunction with a plain back. This is a type of web not only used
for suspenders, but employed extensively for corset garter attachments
also. A web of this character when properly constructed has a smooth
velvet-like face. The threads are uniformly distributed across the width
without showing any of the “rowy” effect from the binder warps, which are
completely hidden by the heavy pile produced by the float of the face
threads. When the contraction of the web takes place, these floating face
threads mass together in a velvet-like pile, not only producing a smooth
handling web but materially increasing the thickness. Such webs are
generally constructed with a six-thread face and a four-thread back, and
have what is termed a round edge, similar to the selvage used on a plain
web. This arrangement shows up the twill face by contrast and gives the
fabric a much finer appearance.
HARNESS AND CHAIN DRAFT
Fig. 1 shows the harness and chain draft of such a web, together with the
construction of a properly balanced web for standard goods of 1⅛ inches
wide. It will be noticed that the face, consisting of 150 threads, is
split up into two warps of 75 threads each. This arrangement is necessary
in order properly to weigh them so as to get a good clearance in the
shed. The warp has to be divided likewise in the harnesses and put on six
harness frames, although the weave could be produced on three. It would
not be practicable to crowd 50 threads on one harness frame in the narrow
space available, as the harness eyes would shoulder and crowd too much
when changing.
In drawing-in this web, one face warp should be arranged so that the
threads are drawn on the first, third and fifth harnesses, and the other
face warp should be on the second, fourth and sixth. Such an arrangement
in the distribution of the warps makes it much easier on the mechanism,
and minimizes the risk of breakages. It is also important to make proper
divisions of the warps at the back rolls, inasmuch as some of the warps
have to be weighted heavily while others are only lightly weighted, and
also on account of the different take-up of the varied weaves.
The back rolls should be set in a graded position so as to prevent undue
friction of one warp against another. The binder warp should be worked
under the front roll on account of the extremely light weight this must
carry. Fig. 2 shows the proper position of the back rolls in relation to
the harness shed.
In a web of this character where the warp stock is somewhat crowded in
the front reed, there is always a tendency for a fibrous yarn to prevent
a perfect clearance in the shed, with a liability of producing occasional
floats through the shuttle skipping these threads. Such floats will pearl
up when the web contracts and make an imperfect face. This trouble may
be prevented by setting the back rolls a trifle higher than the breast
beam rod, so that the stock in the harness which is down will be slightly
tighter than that which is in the upper harness.
The chain draft is so arranged that the face harness will operate to
produce a twill which will be reverse to the twist of the yarn employed,
and thus reduce the prominence of the twill weave all possible. The
filling yarn should be soft, of about 15 turns per inch, and of good
uniform quality, in order to produce a nice selvage and not cut the
rubber. The reed dent inside the selvage rubber should be carefully
twisted at an angle to conform to the nipped in position to the rubber
thread, so that the outside edge of the dent will not cut the rubber when
the reed beats against the goods at the weaving line.
[Illustration: Fig. 1.—Three Leaf Twill, or Satin Face. Woven in
Conjunction With a Plain Back]
[Illustration: Fig. 2.—Showing Position of Back Rolls in Relation to Shed]
USE OF COARSER YARN
A fine looking twill may be produced with a somewhat coarser face yarn by
using a five threaded face over a six-thread repeat. This is shown in the
harness draft at Fig. 3.
In non-elastic fabrics there are available a variety of twill and satin
weaves for the production of soft lustrous surfaces, but this is not so
in elastic webs, as the contraction of the goods after weaving would
produce a ragged, spongy surface. A float of three picks on the face
is about the limit it is practicable to go on an elastic web, with few
exceptions, and even this only in connection with fine picking.
USE OF FOUR LEAF TWILL
A four leaf twill, however, can be used to great advantage when a heavy
body is desired, as for example what is known as “farmer’s web.” These
are usually made about two inches wide, and to further add to their
weight they have what is termed a cushion back, the weave of which is 7
down and 1 up. The use of these soft weaves on both face and back, while
giving the web great thickness on account of the deep velvet-like pile
produced, deprives it of much of its firmness. This condition is met by
the introduction of an auxiliary back warp, underneath the main back
warp, weaving 3 down and 1 up, which knits the upper and lower cloth more
firmly together, thus increasing the firmness of handles of the goods.
[Illustration: Fig. 3.—Five Thread Face Over 6 Dent Repeat]
Another web among the plain loom products calling for passing mention is
that specially made for the police and fireman’s brace. While this has
a 7 down and 1 up cushion back similar to the farmer’s web, it differs
in having a smooth plain face in place of a twill. This arrangement of
combining a plain face with a cushion back necessitates selection of
the sizes of yarn used for the various warps so as to maintain a proper
balance of the different weaves employed in the face and back. Otherwise
the goods would curl up and it would be impracticable to cut them up for
manufacture. Consideration must also be given to the effect of padding
the size upon such goods in the finishing process, of which we will say
more later.
FILLING FANCY EFFECTS
All the webs so far described have been such as could be produced on cam
looms of various capacities. We will now turn our attention to what are
generally understood as fancy effects. It might be well to treat these
under two distinct headings. Those made with the shuttle, or what are
called filling patterns, and those made from the warp, or what are called
stitch patterns.
The figures or fancy effects produced by floating the filling over
sections of the warp show up the filling with increased luster in
contrast to the warp. They are confined to no particular character of
design, and may range from the simplest effect produced on the fancy
harness loom or dobby to the more elaborate jacquard design. The
ground or body may be either plain or twill, or any other acceptable
weave suitable as a base for figuring, while the filling may be of a
contrasting color, either of silk or cotton as desired. The figure or
design may be made from the same shuttle used for the ground or it may
be made by an auxiliary shuttle, either used as an overshot or rise and
fall, according to the character of web desired.
Where the figure is made from the ground shuttle it is produced as
a sunken effect. It is made by burying sections of the face warp at
intervals so that in place of the face warp the filling is seen at these
points. No additional figure warps are required for this class of goods,
and elaborate designs are obtainable, although there is not the scope for
cross coloring that there is in the warp figure method.
STITCH FANCY PATTERNS
When the design is made from the warp, the figure threads are made to
float on the face of the goods so that upon contraction of the web after
weaving, these floats pearl up in prominence above the level of the face,
and make what is termed a stitch figure.
[Illustration: Fig. 4.—Point Draw Stitch Figure]
[Illustration: Fig. 4A.—Harness and Chain Draft for Fig. 4]
It is not our purpose here to particularize in design, which is
practically unlimited, but only to refer to those features which govern
the construction and illustrate as necessary. In order to maintain a
proper balance where figures are introduced on single cloth weaves, it is
necessary to distribute the figure warp uniformly over both the face and
back of the goods so as to maintain a proper balance between the two. In
the double cloth webs the figure warp, when not appearing on the face of
the goods, is allowed to run straight between the upper and lower cloths,
going in the same cavity or pocket as the rubber threads, and it works at
these times as a gut. This, of course, in a measure interferes with the
contraction of the goods and has to be taken into consideration in the
construction. Here again we must note the effect of the contraction in
piling up the floating-figure threads, and the necessity of limiting the
floats in making the design so as to avoid any ragged appearance.
[Illustration: Fig. 5.—Interchanging Figure and Face]
[Illustration: Fig. 5A.—Harness and Chain Draft for Fig. 5]
Fig. 4 shows a design of this character, with the harness and chain draft
at Fig. 4A. In this particular web there are six harnesses used for the
main body and ten for the figure, which is a point draw. While the figure
is evenly distributed on the web, wherever it is not seen it is running
between the upper and lower cloths, as already described, and acting as a
gut.
In order to get a proper balance of the web it is necessary to put gut
threads into the two outer cords where no figure appears, which must
be equivalent in size to the figure threads employed in each of the 21
center cords. If this is not done the web will contract unduly at the
edges and make it “belly.” The method here used of burying the figure
between the upper and lower cloths when not needed in carrying out the
design, affords opportunity for introducing additional warp threads
of different colors, so as to be able to bring up either one color or
another as desired in a design.
As most of the fancy head looms have not more than 18 harnesses, it
will be seen that the scope of design in this class of loom is somewhat
limited, therefore much ingenuity is required to get elaborate designs
from such limited capacity. But careful study opens up a variety of
methods by which a big range of designs is possible.
INTERCHANGING FIGURE AND FACE
Fig. 5 shows another type of design known as the “interchanging” fancy in
which the figure warp does not pile up above the surface as it does in
the stitch figure, but remains flat with the face of the web. The harness
and chain drafts are shown at Fig. 5A. In this character of design a
given number of face threads are duplicated by a like number of figure
threads, the same size of yarn being used for both. These face and figure
threads are drawn in duplicate harnesses and operated just reverse to
each other, so that when the figure is up at any particular part, the
interchanging face threads are down, and vice versa. The figure weaves
only three picks up on the chain draft, which is one face pick seen on
the face cloth, and this produces a perfectly flat web.
Another form of elaboration is shown in this web, known as the “picot”
edge. It is generally made of a well cabled thread of silk and is woven
in the selvage, being bound in for several picks and then allowed to
float outside, so that upon the contraction of the web it will pearl out
in small loops, adding much to the elaboration of the web.