TAPESTRY
TAPESTRY is a fabric made alternatively with a looped pile or a cut
pile, which possesses a close affinity to Brussels and Wilton
respectively, in its appearance and texture. In its method of
manufacture, however, it has something in common with Chenille, inasmuch
as it is essentially a two-process fabric, while the pattern is wholly
in the surface, and is the direct result of the preliminary and not of
the weaving process. No Jacquard is used.
In comparison with its nearest competitors, Brussels and Wilton,
Tapestry is simple in construction, and economical in the quantity of
pile yarn consumed, as there is only one pile warp-thread carrying the
pattern, as against four or five threads in the two fabrics named. It
also has the advantage of a practically unlimited range of colours. On
the other hand, Tapestry is expensive in the preparatory processes, and
requires a high degree of technical knowledge and skill.
The underlying principle of the fabric, which was invented by Mr.
Richard Whytock, of Edinburgh, in 1852, is the attainment of the economy
of using one frame of worsted yarn by printing or painting the pattern
on the threads, instead of using five frames, each of a different
colour. Several methods have been tried for printing the pattern on the
warp, such as printing upon the surface either white or dyed, after
weaving; printing the warp threads collectively before weaving; and
printing the warp threads individually. In the two last named cases the
design or part of the design has to be printed in an elongated form to
allow for the reduction caused by the insertion of the wires in weaving.
Modern Tapestry manufacture, however, has practically concentrated upon
the last-named method; so that the others can be disregarded for the
present purpose.
[Illustration: FIG. 15
DESIGN OF TAPESTRY CARPET]
In common with other carpet fabrics, the design for a Tapestry carpet
must be put upon squared paper, which is preferably, at least, of the
actual size. There is no limitation of colour beyond that imposed by
considerations of taste and of expense. The pitch of the carpet varies
from 7 to 9 per inch, and the beat-up about the same; but the average
quality is about 8 each way.
The design having been prepared, it passes to the printers, who are
responsible for colouring the yarns in such a way that they can be
assembled ready for producing the correct pattern in the weaving. As the
warp carries the whole of the pattern, and the different colours of the
design are printed on the warp threads, the design must be read
lengthwise. Each square on the design paper represents a loop of the
warp in the woven carpet.
[Illustration: FIG. 16
DESIGN IN FIG. 15 ELONGATED AS PRINTED]
The length of colour to be printed on the warp thread must, of course,
bear an accurate relation to the height of the wire used and the number
of wires per inch. This is a matter of calculation. The length of yarn
consumed in 1 inch is determined. This length, divided by the number of
wires, or loops per inch, gives the length of warp yarn to be coloured
for each wire. Thus, for a carpet of nine wires to the inch, 3 inches of
warp yarn are required for each inch of the carpet. The length of each
unit of colour to be printed is, therefore, 1/3 in. The mechanism of the
printing drum is adjusted accordingly, and can be varied for different
qualities.
The normal yarn used in Tapestry varies in count from 10s 2 × 2 to 16s 2
× 3 worsted. It is scoured and dried, and then wound from hanks on to
large bobbins. A set of six of these bobbins, or more or less, filled
with the white yarn, is placed vertically on a stand in front of the
printing drum; and the six ends of worsted are attached at equal
intervals to a triple thread of worsted stretched across the width of
the drum. The threads, properly tensioned, pass through guides, and are
wound on to the face of the drum, the guides being mounted on a rod
which is slowly moved laterally in such a manner that the threads are
laid side by side on the surface of the drum. The revolution of the drum
continues until the whole face is covered, or until the required length
of yarn has been wound. In the latter case, fewer bobbins are put on,
and the drum is left partly uncovered. To fill a drum of ordinary size,
then, there will be required 1,176 threads, which will be obtained from
196 revolutions. Each of the six divisions is called a hank, and is tied
separately. Whatever the number of threads and length of the hank, the
whole length of the yarn on the drum represents one warp thread only.
The printing drum is a large roller constructed with a wooden or tin
face supported upon an iron frame and spokes, the central shaft and
external mechanism being carried upon iron framework. Drums are of
various sizes, varying in circumference from 12 ft. 6 in. to 40 ft., and
in width of face from 18 in. to 72 in., capable of carrying from 700 to
1,200 threads side by side. The most usual width is 30 in. The size of
drums is reckoned by the number of “scrolls” or “types,” that is, lines
of colour, they will carry. These are commonly 216, 324, 432, 648, 864,
or 1,072 scrolls; but an average size is 648.
An essential part of the drum is the double row of teeth cut on a metal
edge attached to one of the outer rims of the drum. These are called
indices and are of different pitch, say 648 and 432, corresponding to
one or other of the scrolls. Each tooth is numbered consecutively, all
round the rim; and the indices represent the total number of scrolls
which can be printed, since the pitch of each tooth permits the drum to
revolve just the width of the scroll pulley. A pawl or scotcher is
arranged so as to engage in each tooth and stop the drum when required.
Before printing, the drum is covered with strips of oilcloth, which are
removable.
[Illustration: FIG. 17
PRINTING DRUM, COVERED WITH YARN, PARTLY COLOURED]
The actual printing or painting of the yarn is effected by means of the
scroll pulley, which revolves in a box The arrows show where the repeats
begin containing the colour, the whole being borne by a carriage running
on rails across the width of the drum at the bottom of the frame. The
colours are made up by an expert colourist to match the required shades,
and by the admixture of flour and water are brought to the necessary
consistency, which is about that of a thin paste, so that the colouring
matter is dense enough to adhere, but liquid enough to penetrate the
yarn fibres. In the carriage, the colour roller, which revolves in the
colour, is supported by springs which tend to give it elasticity and
keep it up against the face of the drum. The carriage is drawn across
the drum by a rope which is mechanically actuated, and, of course,
harmonises with the revolution of the drum. At the end of each traverse
of the colour carriage there is a pause, which gives the printer time to
change the pawl into the new tooth of the index at which it is required.
The printer is guided in his selection of colours for each scroll that
he prints by the “scale board” and the “design board.”
Scale boards vary according to the pitch of the design paper, and
according to the length of the design, and the number of times in which
a design repeats in one revolution of the printing drum. Thus, for a
design on squared paper running seven per inch in its length, the scale
board is marked into divisions of seven to the inch throughout its
length, so as to correspond with the horizontal divisions on the design
paper. Supposing a design repeats four times in the whole revolution, a
quarter board is employed; if it repeats twice a half board, the total
number of scrolls being divided into four or two respectively. Thus, if
the size of the drum is 648 scrolls and the number of wires in one
repeat of the pattern is 162, the quarter board will have four vertical
columns of figures, running respectively 1-162, 163-324, 325-486, and
487-648. The scale board has a bevel edge, and is preferably arranged so
that it can be moved over the design board and aligned with the vertical
line of the design which the printer is reproducing.
[Illustration: FIG. 18
SCALE AND DESIGN BOARD COMBINED]
Fig. 18 represents part of a scale and design board combined. The
numbers along the top indicate the threads in the design, and the
printer may be supposed to be ready to print the eighth thread. The
numbers on the right-hand side represent the wires in the carpet, with
which the numbers on the scale board and the scrolls in printing
correspond. The design is 216 wires long; and as the number of scrolls
the drum will take is 648, the design is repeated three times in one
revolution. The scale board is numbered in three columns; and for the
first, second, and third repeats of the design, the printer uses the
first, second, and third divisions on his scale.
To minimise the danger of bad effects from a colour running, the rule is
to begin printing with the lightest shade. In this instance, the
lightest colour is yellow, represented (heraldically) by spots, and it
occurs first at the fourth horizontal line. The printer, therefore,
turns the drum by hand, and puts the pawl in tooth number 4. He then
puts the mechanism in gear and prints the scroll in the manner
described, following on immediately by printing a second scroll at
number 5. He then reads further down the eighth vertical line of the
design, and sees that the colour recurs at 10, 11, 18, 19, 24, and 25.
He therefore puts the pawl in the corresponding teeth of the index
consecutively and prints accordingly. When all the yellow squares
corresponding to the first column of the scale board have been read, he
will take the second column, and print 220, 221, 226, 227, 234, 235,
240, 241 and so on, and then those in the third column. The remaining
colours will then follow on in order of their delicacy.
When the printing of a drum has been completed, the next process is
scraping. The scroll pulley in the act of printing always conveys more
pigment on to the yarn than is needed to colour it, a little wall of
material being left on each side of the path of the roller. This has to
be removed, or it would smudge. This is done by means of small vulcanite
tools, bevelled to a blunt edge, from ½ in. to 2 in. wide, the operator
being aided by a steel bar fixed across the face of the drum as a guide.
Scraping has, however, a further purpose beyond the removal of
superfluous colour, and one no less important; for by skilful pressure
and rubbing, the colour is caused to penetrate more deeply into the
yarn.
[Illustration: FIG. 19
A SCRAPER]
The yarn, having been printed and scraped, has now to be taken off the
drum; a process known as “stripping.” The threads are looped together in
hanks, and numbered with a ticket to show which thread each represents
in the design. The drum is so constructed that a section of it can be
drawn inwards upon a telescopic arm of the drum frame. The yarn is thus
released from its tension round the drum face; and the strippers,
inserting long sticks under the oilcloth, lift it and the yarn clear of
the drum. One side of the frame which carries the drum shaft is made
removable to enable the yarn to be taken away.
The long hanks are then ready for steaming. They are placed with as
little handling as possible upon latticed frames filled with oat-husks.
The frames are then run into an iron-walled steam-chest, which is
securely closed, and into which steam is turned at high pressure. The
effect of the steam pressure and heat is to fix the colours on the yarn.
The operation takes about half an hour. Some makers prefer to put the
hanks into net bags for steaming, or to lay them on network frames,
without the bran. But the first method described is probably the best,
as the bran tends to absorb the superfluous colour, and prevents it from
dripping from one hank on to another.
After steaming, the hanks are thoroughly rinsed, preferably by a large
rocking arm fitted with a hook, in cold running water. The yarn is then
partly dried in a hydro-extractor and finished in a stove. Each hank is
then wound on to large bobbins, which are numbered so that the setters
know to which part of the design each belongs.
[Illustration: FIG. 20
PRINTED THREADS SET FOR WINDING ON TO THE BEAM]
The next process is setting. The object of the operations up to this
point has been to make a set of warp threads which contain the pattern
of the carpet in an elongated form in such a way that, when woven in the
loom, the loops as seen in the carpet will accurately reproduce the
design. It is the business of the setters to arrange the threads
alongside one another in proper order and dressing so that they form the
pattern, and to wind them thus arranged on to the warp beam.
[Illustration: FIG. 21
FIG. 20 AS WOVEN]
The warp beam is at one end of the setting frame; the bobbin-stand,
which moves on pinion feet upon a rack, at the other.
[Illustration: FIG. 22
STRUCTURE OF TAPESTRY CARPET
W, Wires]
The bobbins having been set in proper order on the vertical pegs in the
bobbin frame, the ends from them are led between guide rails, through a
sley, through two halves of a clamp, over the setting table, through
another sley, and a second clamp, on to the warp beam. In the first
instance, the setters hold down the yarn in the clamp next to the warp
beam. They then adjust and manipulate the threads over the setting
table, which is marked with horizontal lines, in accordance with the
pattern.
[Illustration: FIG. 23
MEDIUM TAPESTRY CARPET
A, Chain; B, Pile warp; C, Stuffer warp; E, Weft]
The other clamp is then screwed down, the first one unscrewed, and the
yarn wound on to the beam, the bobbin-stand moving forward along its
rack up to the setting table. This operation is continued until the
whole of the yarn has been wound from the bobbins on to the beam, which
is now ready to be put into the loom and woven.
[Illustration: FIG. 24
TAPESTRY VELVET. 3-SHOT]
The method of weaving is substantially the same as with Brussels; and
except for the pile warp beam, which is generally placed high up at the
back of the loom, and for the absence of a Jacquard, the mechanism of
the loom is not dissimilar. There are three heald-frames: two for the
two halves of the cotton chain, and one for the stuffer and the pile
warp, the jute and worsted being threaded through two eyelets, one below
the other. The Tapestry loom is run at rather a higher speed than the
Brussels, the Moxon or switch principle of wire motion, which is
generally adopted, tending to make this possible. A double stuffer, that
is, two ends of jute, of 14 lb. or 16 lb. count, to each reed, is used
for an average quality; and a treble stuffer where greater weight is
required.
[Illustration: FIG. 25
TAPESTRY VELVET
A, Chain; B, Stuffer warp; C, Pile warp; D, Weft]
Tapestry velvet bears the same relation to the looped fabric as Wilton
does to Brussels, the essential difference being the use of a
knife-ended wire, instead of a round wire. The use of three weft shots
per row of pile is not, however, the almost invariable rule in Tapestry
velvet, that it is in Wilton.
[Illustration: FIG. 26
TAPESTRY VELVET. 2 SHOTS IN THE GROUND]
A three-shot fabric is, of course, more expensive to make than a
two-shot; and there is also the consideration that, unless the pile is
pretty high, the double shot on the top will tend to make the surface
grin. The method, therefore, of using a double shot in the ground is
sometimes adopted. (Fig. 26.)
The Tapestry branch of the carpet trade has naturally passed through a
development similar to that of other makes, in that it has found the
demand passing from piece goods to sewn breadth squares, and from them
to seamless carpets; and it has progressed accordingly. The greater part
of the Tapestry trade at the present time is done in squares, and the
enquiry for carpets 9 ft. and 12 ft. wide seems to be a growing one.
This tendency throws additional burdens on the manufacturer. Square
carpets involve more designing and more printing than piece goods; and
the amount of preparation required is a very serious item. Before one
complete carpet can be produced, preparations have to be made for from
200 to 300, or, in the case of medallions, double the number. That is
one of the disadvantages of the manufacture; a further defect is
inherent in the fabric. However accurately and carefully the processes
of printing, scraping, setting, and weaving may be carried out, the
transition from one colour to another cannot be made quite sudden and
complete. The colour will appear to have run; and the shade which
belongs to one wire will tend to trespass on to the next. This means
that with Tapestry it is never quite possible to produce the
clearly-defined pattern effect, which is produced in Brussels and
Wilton, and which is naturally looked for in all fabrics of moderately
fine pitch.
Apart from this, the Tapestry carpet has much to commend it. It can be
produced and sold at a moderate price; it can be made seamless, and it
has great potentialities of design; while, for those who like plenty of
colour, the range of shades available is practically unlimited.