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Fig. 387.



Fig. 388.



Corduroy Cutting.

§ 78. The cutting of corduroy fabrics is performed, as previously
stated, sometimes by hand, similarly to that employed for vel-
veteens (as described in §§ 65 and 66) ; but perhaps more ex-
tensively by machinery, as their coarser and stronger texture



158



GRAMMAR OF TEXTILE DESIGN.



renders them better adapted than velveteens to mechanical
cutting. Fustian-cutting machines comprise various modifi-
cations of two distinct types, known as ''circular-knife" and
'* straight-knife " machines. A graphic full-scale diagram illus-
trating the operation of a " circular-knife " machine is shown in
Fig. 391. In this machine all cords across the entire width of
cloth are simultaneously cut by means of a corresponding number




Fig. 389.— Figured Corduroy, woven from Design Fig. 390.

of thin sharp-edged steel discs B, placed at regular intervals
(coinciding with the width of cords) upon a mandril A, which
extends across the machine and revolves with considerable
velocity in the direction indicated by an arrow, D. As the knives
revolve, cloth advances towards them in the direction indicated
by an arrow, F, to a point H, where it is sharply deflected over
the bevelled edge of a cross-rail G. At this point, floats of weft
forming each "race" are directed and presented by means of



FUSTIANS.



159



guide wires E to their respective knives, to be cut. A guide wire
B is inserted in each "race," with the lower portion of a knife
partially entering its long narrow slot. Guide wires E are pieces
of steel wire bent acutely to form a long loop. The extremities of
the wire are soldered together where they meet, whilst the curved




Fig. 390.— Design for Figured Corduroy represented by Fig. 389.



end is flattened and sHghtly bent as shown. They are inserted
in the ''races " of cloth with the point downward and pointing
in the opposite direction to that in which cloth approaches the
knives. Guide wires serve the functions of (a) guiding floats of
weft forming a "race" to the knives, and tautening them as
they are cut ; and (6) keeping the knives (which are not rigid,



160



GRAMMAE OF TEXTILE DESIGN.



but somewhat freely placed upon the mandril) in the centre of
each "race". A small segment is cut off each knife, as shown
at C, to reduce their diameter at that part. Thus, by turning
the mandril until the straight edges C of the knives are at the




cutting point H, it allows a little greater space between the
knives and the rail edge, thereby facilitating the insertion of
guide wires in the " races " at the commencement of cutting, or
subsequently for the replacement of wires that may become
injured.



FUSTIANS. 161

As the uncut cloth approaches the knives, guide wires are con-
veyed along by it, and consequently require to be pushed forward
again intermittently. This is accomplished by means of pushers
actuated at frequent and regular intervals by a series of spirally
arranged rotary cams. Each pusher acts upon three or more
guide wires (according to the width of cords) at their soldered
ends, so as to push them forward in groups instead of collec-
tively, thereby ensuring greater constancy of action by prevent-
ing extreme fluctuations of energy exerted by the machine, and
also of motive power required to drive it.

§ 79. Fustian-cutting machines of the second-named type are
constructed with either four stationary knives, or one stationary
knife, to cut four cords simultaneously, or only one cord at a
time, respectively. In either case, the extremities of cloth to be
cut are sewn together to form an endless band or web, which is
passed through the machine at a rapid pace as often as is re-
quired to complete cutting. After each complete circuit of cloth
the machine is stopped, and the knife or knives adjusted by
hand to cut the next "race" or "races". In a four-knife
machine, the knives (which are similar to those employed in
hand cutting) are fixed at intervals corresponding to one-quarter
of the width of fabric to be cut, and operate in a similar manner
to a hand fustian knife, excepting that cloth advances upon the
knives in the former, whilst in hand cutting a knife is thrust
along cloth which is held stationary. The adjustment of knives
in these machines is so contrived that, on their leaving a
" race," penetrating cloth, meeting with any obstruction, or from
any other irregularity, the machine automatically stops.



11



CHAPTER VIII.

TERRY PILE FABRICS.

§ 80. " Terry pile " is a terra used to distinguish a variety of
woven fabrics characterised by the formation of a series of loops
(thus f[) projecting from the main body of the fabric. These
loops are produced by an extra series of comparatively slack
warp ends, and may be uniformly distributed either on one side
or both sides of the fabric to form a perfectly even surface ; or
they may be developed in such manner as to create a figured
design upon a plain or bare ground. Or, again, a figured terry
fabric may contain an all-over pile surface on both sides, with
figure and ground developed in contrasting colours.

There are two distinct methods of developing a terry or looped
pile surface during the operation of weaving, namely : (1) by
means of wires that are inserted in the warp sheds at intervals
(as if they were picks of weft) and subsequently withdrawn, there-
by causing all warp ends that passed over them to form a corre-
sponding number of loops ; and (2) by means of what are known
as " terry " motions, whereby, during weaving, several picks of
weft are inserted a short distance from the " fell " of cloth (or
last pick inserted), to produce a short gap or " fret," and then
all are pushed forward together to take their final place in the
fabric. As each group of picks are thus pushed forward by the
reed, pile warp ends buckle or loop either on the face or back of
cloth as predetermined, and so develop the characteristic loops
of pile known as " terry," looped, or uncut pile.

Examples of looped pile fabrics produced by the aid of wires
are seen in Brussels and tapestry carpets, moquette, mohair
and other furniture upholsterings of heavy texture, as well as
in silk upholsterings of light texture and great beauty. In

(162)



TERRY PILE FABRICS. 163

fabrics of this description the pile is formed on one side only,
and (with the exception of tapestry pile carpets) pile warp ends
may sometimes lie perfectly straight or interweave as ordinary
warp ends, and then be required to form pile, all within a short
interval. Under these circumstances, pile warp ends are separ-
ately contained upon a corresponding number of bobbins that
.are separately weighted to permit of the independent withdrawal
-of their threads, and thus provide for their variable and irregular
contraction. If all pile warp ends were contained on the same
warp beam, they would necessarily have to either form pile or
■else lie straight uniformly at the same periods, in consequence
of their uniform and simultaneous delivery during weaving.

^ 81. Terry fabrics produced by means of terry motions are
•exemplified in so-called Turkish towels, bath mats, counter-
panes, antimacassars, toilet covers and mats, and many articles
for domestic purposes. The majority of these goods are produced
entirely from cotton, although terry towels are sometimes pro-
duced either entirely or in part from linen. Terry weaving is
a principle eminently adapted to the production of towels, as
the loops of pile give considerable bulk and impart good absorp-
tive properties to the fabric. The variety of terry fabrics under
present notice are produced from two series of warp ends,
namely : (a) ground, and (b) pile warp ends, each of which is
■contained on a separate warp beam. They are usually employed
in equal proportions, and arranged in the harness and reed either
alternately with each other or in alternate pairs of ground and
pile threads. The particular disposition of warp ends is arbitrary.
'Some advocate an alternate distribution of ground and pile warp
•ends, whilst others prefer to dispose them in alternate pairs of
each series of warp ends. In both cases the ultimate results
are virtually alike. During weaving ground warp ends are held
taut, whilst the beam containing pile warp ends is very lightly
weighted to enable the threads to be easily withdrawn for the
formation of pile. Terry fabrics are termed three, four, five or
six-pick terry s, according as there are three, four, five or six
picks inserted between each horizontal row of loops respectively.
Most of these fabrics are constructed with three picks for each
row of loops. The object of inserting a greater number of picks



164



GEAMMAE OF TEXTILE DESIGN.



for each row of loops is to produce a superior fabric and to bind
pile warp ends more firmly to the foundation texture.

§ 82, Before describing the construction of terry fabrics it will
be better to briefly describe the general features of terry-forming^
devices, as that will be helpful to a clearer understanding of the
essential conditions governing the construction of such fabrics.
Terry motions are usually based upon one or other of three
distinct mechanical principles. By far the greater number are
constructed on what is known as the "loose -reed" principle,
illustrated in Fig. 392. Devices based upon this principle ar&




Fig. 392. — Loose Eeed Action, for Terry Pile Weaving.

designed to act upon a reed in such manner that, as the sley
comes forward, the reed is caused to swing backwards at the
bottom from its normal vertical position to an inclined position
for two out of three or more picks, and is afterwards securely
fastened in its normal position for the following pick (or picks),
when all are pushed forward together to take their final place in
cloth. As picks are thus pushed forward from their temporary
to their final position, they slide along the tense ground warp
ends ; but the degree of frictional resistance between the three
picks and slack pile warp ends is sufficient to draw the latter
forward en masse, and thus cause them to bend and form a series



TERRY PILE FABRICS. 165

of loops. As the reed swings backward at the bottom, for the
two "loose" picks, it swivels on the upper ribs which are re-
tained in a mortise cut into the under side of the sley cap.
Therefore, since the line of contact made by the ''fell " of cloth
with the reed is situated approximately midway between the
upper and lower ribs of the latter, it follows that the bottom of
the reed will require to recede (for the two "loose " picks) for a
distance of not less than twice the length of gap or "fret " neces-
sary to yield the desired length of pile on the fabric. Such ex-
cessive backward movement of the reed creates a tendency to
•develop loops of pile of irregular lengths in different horizontal
rows of pile, but not in the individual rows. This tendency
arises in consequence of the abnormal inclination of the reed
from its vertical position, whereby it inclines forward at the top,
and therefore bears downward upon the "loose" picks as it
approaches the "fell" of cloth. Hence, those picks tend to
slide downward along the reed for a greater or less distance
{according to circumstances to be presently stated), and, thus
produce gaps or " frets " of different lengths, and, therefore,
different lengths of pile. This evil is more liable to manifest
itself m figured terry fabrics in which the number of pile warp
ends either raised or depressed is liable to fluctuate according to
the design. Thus, the '' fell " of cloth will occupy a higher or
lower plane during beating up, according to the preponderance
of warp ends in either the upper or lower half of the warp shed,
respectively; also, the strain upon the reed, as it approaches
the " fell " of cloth, will be greater or less in proportion to the
number of warp ends forming the bottom half of the warp shed,
because they bear against the reed farthest from the upper ribs
on which it swivels in the sley cap.

A modification of the "loose-reed " principle, for terry weav-
ing, is designed with the object of overcoming the disadvantages
of the system just described. This modification is effected by
mounting the reed in a case or frame carried at the upper ends
of two long vertical arms that extend downwards and are re-
spectively fulcrumed either upon studs secured to the sley swords,
or else upon the rocking shaft on which the sley oscillates. The
said arms are analogous to auxiliary sley swords for the sole



166 GKAMMAK OF TEXTILE DESIGN.

purpose of supporting the reed only, so that the latter may be-
carried bodily backward, with the least deviation from its normal
vertical position, when beating up the two "loose" picks to
produce the desired length of gap or "fret" at the "fell" of
cloth.

A second type of terry motion causes the sley to oscillate for a
shorter distance for two consecutive picks, and for a greater dis-
tance for the third and following picks inserted for each hori-
zontal row of loops. By this means, two out of three or more-
picks are beaten up within a short distance from the "fell" of
cloth, and then after the third pick is inserted in the shed they
are all three pushed forward together as described.

A third type of terry motion (which is of little reputation)
operates in a contrary manner to either of the foregoing. Thus,
instead of causing the reed to recede for a short distance from-
the "fell" of cloth, the latter is drawn a short distance in ad-
vance of the reed for the two "loose" picks; whilst the reed
is fixedly mounted in the sley, as in a " fast-reed " loom. This-
is accomplished by moving the back rail and breast rail of a loom
' to and fro simultaneously, so as to carry the stretch of warp and
cloth bodily forward for two out of three or more picks, after
which, the back rail and breast rail return to their normal posi-
tion, thereby causing all picks to be pushed forward to their final
place in cloth.

§ 83. Fig. 393 is the design for a plain three-pick terry fabric
shaving pile formed on both sides, and with warp ends arranged
in the order of one ground and one pile warp end alternately.
(Shaded squares in the design represeat pile warp ends and black
squares ground warp ends.) In the production of terry piece-
goods, such as roller towelhng, not more than four healds are
necessary, namely, two for each series of warp ends ; but in the
production of separate towels, with "headings " or borders, it is
usual to erqploy five healds, namely, two (at the front) for pile
warp ends, and three (in the rear) for ground warp ends, drafted
in the manner indicated above the design. When pile and
ground warp ends are arranged alternately, one of each series
is drawn through each dent of the reed ; but when they ar&
drafted in pairs they are also passed through the reed in pairs,.



TERRY PILE FABRICS.



167



so that two warp ends of the same series are contained in the
same dent. In § 88 the relative merits of each system of drafting
and other practical considerations are stated. On examining
the design, Fig. 393, it will be seen that consecutive ground warp
ends interweave in an opposite manner to each other, as do also
consecutive pile warp ends. Pile warp ends that are over two
picks and under one pick form pile on the face, whilst those that
are under tivo picks and over one pick will form pile at the back
of cloth when in the loom.

§ 84. In the production of terry fabrics without the aid of wires
it is absolutely essential to observe a specific order of shedding in
relation to the action of the reed as governed by the terry motion.



GROUND HEALDS



PILE



RE ED
REED
REED
REED
REED
REED



HEALDS I

REED-H

FAST
LOOSE
LOOSE

FAST
LOOSE
LOOS E





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FIRST


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SECOND


PICK




PICK




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Fig. 393.— Design for a 3-Pick Terry Pile Fabric.

otherwise the loops of pile will be imperfectly developed or may
not appear at all. This order is clearly indicated in the design
(Fig. 393) and also in the graphic diagram (Fig. 394) which re-
presents a longitudinal section of a three-pick terry fabric. On
examining these figures it will be seen that the reed is " loose "
for the first and second picks, termed " loose " picks, and "fast "
for the third pick, termed the "fast" pick. It will also be ob-
served that the "loose" picks are always inserted in opposite
pile warp sheds, but in the same ground ivarp sheds. With
this order of shedding in relation to the reed motion, pile warp
ends make two intersections, and ground warp ends only one
intersection with the picks, before the latter are beaten up to



168



GEAMMAR OF TEXTILE DESIGN.



the " fell " of cloth ; hence, the picks easily slide along ground
warp ends which are held taut, whereas their better grip of
pile warp ends which are slack causes the latter to be drawn
forward and form loops of pile.




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§ 85. As stated in § 81, the number of picks inserted between
each horizontal row of loops in terry pile fabrics produced by
the aid of terry motions varies in different fabrics from three to
six picks. The number of picks selected does not, however.



TEKRY PILE FABRICS.



169



atfect the primary factor governing the construction of those
fabrics as regards the order of shedding in relation to the timing
of the reed motion as described in § 84. This is specially
emphasised because it constitutes one of the most essential
conditions in terry weaving, and the want of such information
sometimes proves a stumbling-block to the successful production
of terry cloth. It should also be observed that the relative
density of loops of pile is relatively greater or less in inverse
proportion to the number of picks inserted for each horizontal
row of loops.

Fig. 395 is the design for a four-pick terry fabric having pile
equally distributed on both surfaces. A longitudinal section of




Fig. 395.— Design for a 4-Pick Terry Pile Fabric.

cloth produced from that design is graphically represented in
Pig. 396. It differs from a three-pick terry fabric by having two
picks (the fourth and first that are contiguous) inserted in the same
warp shed, a circumstance which necessitates the use of a ** catch-
cord " for one of the selvedges. (A " catch-cord " is a device to
govern extreme outer selvedge warp ends, so that weft will be
caught by them and thereby prevented from being pulled back-
ward into the warp shed in the event of a shuttle passing through
the same shed for two or more picks in succession.) By insert-
ing four instead of three picks for each horizontal row of loops, a
firmer and heavier texture is produced. Also in the manufacture
of those fabrics in which differently coloured threads are em-
ployed to produce simple counterchange effects (as exemplified



170



GRAMMAR OF TEXTILE DESIGN.




TERKY PILE FABEICS.



171



in many terry towels and bath mats) jit enables a sharper and
more perfect definition to be made at the horizontal edges of
figure, where pile threads pass from face to back, and vice versa.
The starred numbers 1 and 2 in Fig. 396 and subsequent
diagrams of terry fabrics signify that the reed is loose for the
picks indicated, and fast for the intermediate picks, during
weaving.

v^ 86. Another modification in the construction of terry fabrics
is exemplified in the well-known Turkish towel, sold under the
trade name of " Osman," of which the design and longitudinal
section are given in Figs. 397 and 398 respectively. So far as



REED


FAST


lOr.


FAST


dff.


FAST


da


FAST


ob.


LOOSE


dff.


LOOSE


do


F


da.


F


da


F




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Online LibraryHarry NisbetGrammar of textile design (Volume c.2) → online text (page 10 of 19)