JAQUARD MACHINE
Sumber :
Muramatsu, Soji.1958.Jacquard Weaving.Murata Textile machine Co., Ltd: Kyoto,Jepang.
A. Single lift Jaquard Machine
This is a quite ordinary type of jaquard
and the mechanism is simple. In most cases, one warp end and in a figure repeat
is controlled by one hook and the sheed formed is either the over-shed or the
center shed
a. Single lift cylinder over shed Jaquard Machine
In this type of jaquard, the hook-board is fixed and
the hooks are moved only by the knives.
The warp ends, when the knives rise, are raised from
the warp line and form the over shed according to the weaves. After the picks
pass through, they must return to the warp line
Advantages
1.) The shedding motion is simple
2.) Warp ends are loaded with large tension during the shedding motion and
thus woven fabrics with tight yarns are possible to produce.
Disadvantage
1.) Half turning of crank shaft is not smooth on account of the closing of
the shed, and the loom is loaded unevenly during the driving.
2.) As it takes much time for the
shedding motion, high speed driving can not be employed.
3.) During one revolution of crank shaft, the ratio of time for shedding
much larger than that for the passage of shuttle, therefore this type of machine
is not fit for looms of large width
4.) Warp ends being strained in shedding, are easily torn.
b. Single lift single silinder center shed Jaquard Machine
The knife box and the hook board move up and downward
oppositely at the same time and thus two reverse directions of motion work on
the hooks. Therefore some warp and the center shed is formed. The moving
distance of warp ends for center shedding is about half in comparison with the
over shed, and there are , besides, following advantages and disadvantages with
this type of machine. However, this is a far more improved type than the over
shed type of jacquard machine.
Advantages
1.) In shedding, the strain on the warp ends is small and very few are
broken
2.) Warp ends ascend and descend at the same time and according to the
compensating principle motive power can be saved and still more, the uneven
load on the loom is small
Disadvantage
1.) The lingoes sway increasingly
2.) Reed marks are often seen on the fabric
B. Double lift jaquard machine
This type of machine, which control one
warp end by two hooks, is equpped with two groups of knive which ascend and
descend alternately. This works the above mentioned hooks, and the knives are
so designed that one is at the top while the other is at the bottom. When the
shedding motion commences, the lower knifes move upward and the upper ones move
downward and meet in the middle of their course and they are replaced
completely. Therefore these warp ends placed at the top or the bottom of the
shed are moved respectively at the same time as the shedding motion begins.
In other words those warp ends which rest
at the top of the shed, according to the descent of the upper knife, descent
around the middle of the shed, and
1.) The warp ends which need not to be raised in the following pick, as the
lower hooks are not hung on the knife by pushing of the card paper, therefore
the warp ends decent to the bottom rest line
2.) The warp ends which need be raised in the following pick,as the lower
hooks, are also hung on the knife till they reach the top of the shed, where
the so-called semi-opened shed is formed
On the other
hand, those warp ends rested at the bottom of the shed are raised around the
center of the shed as the lower hooks ascend, but in case the hooks not being
raised, they remain at the bottom,
They are two
kinds of this types of machine, double lift single silinder and double lift
double silinder jaquard machine. Both of which are good and weak in the
followings:
Advantage:
1.) The revolutions per minute of loom can be increased
2.) As the time for the biggest shed is long, so the adjusment of picking is
easy
3.) The uneven load on the loom is small and the loom running is smooth
Disadvantage
As the warp
ends are separated into two sheets, the warp tension is not even in shedding
a. Double lift single silinder jacquard machine
There are two kinds of these machine, one has double
the number of hooks with needles compared with the single lift jacquard machine
and the other with the double number of hooks only.
Fig 16 is one of the latter type and the combination
of hooks, needle and warp yarns are as follows:
Needle number
|
Hook number
|
Warp number
|
1
|
1 – 2
|
1
|
2
|
3 – 4
|
2
|
3
|
5 – 6
|
3
|
4
|
7 – 8
|
4
|
5
|
9 – 10
|
5
|
6
|
11 – 12
|
6
|
7
|
13 – 14
|
7
|
8
|
15 – 16
|
8
|
There are two kinds of knives, X and Y the former
controls the odd numbered hooks and the latter, the even numbered ones. They
move up and downwards alternately at every picking. Cylinder M as shown in the
figure, approaches closely when the two kinds of knife situated at the top and
bottom of the shed, and the cards contact with the needles thus one piece of
card is used for every one pick
b. Double lift double cylinder Jacquard machine
This machine seems to be like jaquard machine that is
contructed with 2 sets of single acting jacquard which were fitted on a single
jacquard framing. So they have 2 sets of cylinder, needles and hook and 2 sets
of card are passed around the 2 cylinder respectively, the odd number cards are
passed around the 2 cylinders respectively, the odd number cards hung around
one cylinder, and the even numbered on the other , at every pick the cylinder
move alternately.
Advantages
1.) The hook recive less strain than in the case of the single cylinder
machine
2.) On high speed running, the cylinder beat againts the needles smoothly,
smoother than the single cylinder machine
Disadvantages
The double
cylinder machine has some unfortunate chances of defects on the cloth when both
cyilinder would miss their regular acting order.
c. Springless double lift double cylinder Jacquard machine
The ordinary ajcquard machine has a spring box, but
the springless double lift double cylinder has none. Accordingly the hooks
return motion will be done by itself by their own elasticity
In the figure 19 A, iron rods P are arranged side by
side among the rows of pairs of hooks and they act as folcrum of the hook when
they are pushed by needles.
When the needle manipulates a pair of hook, 2 knives X
and Y are raised and lowered alternately, so that the knives move the warp the
same as in the case of double cylinder machine and makes semi open shed.
C. Cross Border Jacquard machine
It is used in manufacturing fabrics with
figuresd border as handkechief or table cloth of fabric with skipped figures,
being aimed at saving cards and high productivity. This machine equipped with
two cylinders, one cylinder is used to figures on the ground part and the other
for the border of fabrics. In other case the same (2 cylinder) are used for
figures and the ground weaves.
Fig 20 shows one of this type machine based
upon the double lift single cylinder Jacquard machine, where M and N stand for
two cylinders, A for ordinary kind of needle s, E is auxilliary needles. Those
two kind of needles are connected with vertical pins F. Needle E are not
equipped for springs at their ends, but are pushed successively towards
cylinder N by the spring of A by way of F.
D. Veldol Jacquard machine
This new type jacquard machine and has
finest needle pitch, in which the needle are arranged in zig zag line, moreover
cotinous roll of paper are used for the card, therefore this small type machine
can weave large figured cloth.
As shown in fig. 23 there are provided two
kinds of hooks and needles H, h and N,n. And a endless cards paper is hung on
the circular cylinder C, and that the perforated paper passed through between
the cylinder and guide bar and the paper is moved forward by the action of
cylinder rotation . auxiliary needles terminate at right end with a small head.
There are angle pieces “a”, which are oscillated
laterally, when angled pieces are moved to the right , they push the
corresponding needle N to the right, then the hooks H are departed from knife edge.
The veldol Jacquard machine has many
advantages, that making saving the cards and the lacing time mostly, the smooth
running card can be get. However they have some disadvantags, the card can not be mended when the card is miss cut,
and the machine controlling is difficult and skillness is required for
mastering the Jacquard machine, so that they are not worling at japan,
generraly.
