Take-up method of continuous filament bundles of synthetic fibers and apparatus therefor

Method for the take-up of continuous filament bundles of synthetic fibers at a high speed, which comprises introducing the continuous filament bundles discharged from an air jetting device and carried on the air stream into a bent tube provided downstream from the air jetting device, which is rotating in substantially reverse direction to that of the continuous filament bundles discharged from the outlet of the bent tube at a peripheral speed of the outlet thereof being 0.5 to 2.0 times the take-up speed of the continuous filament bundles (e.g. 2,000 to 6,000 m/min.), and receiving the continuous filament bundles into a receiving device provided downstream of the bent tube, and an apparatus useful for the take-up of the continuous filament bundles.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to a method and apparatus for the take-up of 
continuous filament bundles of synthetic fibers at a high speed. More 
particularly, it relates to a method for the take-up of continuous 
filament bundles of synthetic fibers, such as yarns and tows, or the like 
at a high speed, comprising introducing the continuous filament bundles 
carried on the air stream into a bent tube provided downstream of the air 
jetting device, which is rotating in substantially reverse direction to 
that of the continuous filament bundles discharged from the outlet of the 
bent tube at a peripheral speed of the outlet thereof being 0.5 to 2.0 
times the take-up speed of the continuous filament bundles, and receiving 
the continuous filament bundles into a receiving device, and an apparatus 
therefor. 
Hitherto, the take-up of a number of yarns (e.g. tow) has been carried out 
by using a pair of gear rollers or a pair of belts, between which the tow 
is put and taken up. With the speed up in the treatment of the tow for 
improving the productivity and for rationalizing the procedure, it is 
required to take up the tow at a higher speed. For instance, when the tow 
is taken up at a high speed of 2,000 m/min. or more, the conventional 
methods using gear rollers or belts have a defect that the tow is wound 
around the final take-up rollers due to the accompanying air stream. For 
eliminating the defect, it has been proposed to provide an air jetting 
device in the high speed take-up method. However, when the tow discharged 
from the air jetting device is directly received into the tow receiving 
device, the received tow is disturbed by the air stream jetted out 
together with the tow, and thereby, when the tow is drawn out from the 
receiving device in the subsequent step, the tow becomes entangled and can 
not stably be drawn out. There has also been proposed a method comprising 
striking the tow discharged from the air jetting device onto a lattice or 
net drum, by which the tow is separated from the air stream, and then the 
tow is taken up. However, according to this method, when the tow is 
struck, it is somewhat crimped and entangled, and therefore, when the tow 
is drawn out from the receiving device in the subsequent step, the tow can 
not stably be drawn out because it has become snarled. 
Under the circumstances, the present inventors have intensively attempted 
to eliminate these defects in the conventional methods for taking up the 
continuous filament bundles. As the results, it has been found that the 
object can be accomplished by using a bent tube which is rotating in a 
substantially reverse direction to that of the continuous filament bundles 
discharged from the outlet of the bent tube at a fixed speed. 
An object of the present invention is to provide an improved take-up method 
of the continuous filament bundles of synthetic fibers at a high speed. 
Another object of the invention is to provide an apparatus useful for the 
take-up of the continuous filament bundles of synthetic fibers at a high 
speed. 
These and other objects will be apparent from the following description. 
The take-up method of the continuous filament bundles of synthetic fibers 
(hereinafter, referred to merely as "yarns") of the present invention 
comprises introducing the yarns discharged from the air jetting device and 
carried on the air stream into a bent tube provided downstream from the 
air jetting device, which is rotating in substantially reverse direction 
to that of the yarns discharged from the outlet of the bent tube at a 
peripheral speed of the outlet thereof being 0.5 to 2.0 times the take-up 
speed of the yarns, and receiving the yarns into the receiving device 
provided downstream from the bent tube. 
The apparatus useful for the take-up of yarns at a high speed according to 
the present invention comprises an air jetting device provided downstream 
from the final take-up rollers, a bent tube provided downstream from the 
air jetting device, and a receiving device provided downstream from the 
bent tube. 
According to the present invention, the winding of the yarns onto the final 
take-up rollers can be prevented by using the air jetting device, and 
further, by introducing the yarns discharged from the air jetting device 
into the bent tube together with the jetting air stream and moving the tip 
of the bent tube circularly in substantially a reverse direction to that 
of the stream of the yarns and the air, at a speed approximately equal to 
the take-up speed of the yarns, the yarns and the jetting air are 
discharged from the outlet of the bent tube at an absolute speed of 
approximately zero. Therefore the yarns are stably, without any 
disturbance, disposed into the receiving device.

The present invention will be more clearly understood from the following 
description referring to the accompanying drawings. 
In the drawings, FIGS. 1, 2 and 3 show the conventional apparatus for 
take-up of yarns. FIG. 1 is a front view of a conventional take-up 
apparatus using gear rollers. The yarns T are hauled by the traction 
roller 2, passed through the gear rollers 3 and received into the yarn 
receiving device 1. When the yarns are taken up at a high speed (e.g. 
2,000 m/min. or more) by this method, the yarns T are wound around the 
gear rollers 3 due to the accompanying air stream which occurs around the 
gear rollers 3, and thus cannot be stably taken up. For eliminating this 
defect, it has been proposed to use an air jetting device. In the method 
using the air jetting device, when the yarns discharged from the outlet of 
the air jetting device are received into the receiving device together 
with the jetting air, the received yarns are disturbed by the air stream 
and thus the yarns become entangled and cannot stably be drawn out in a 
subsequent step. For eliminating this defect, there have been proposed 
various methods as shown in the following FIGS. 2 and 3. 
FIG. 2 is a front view of a conventional take-up apparatus using a lattice 
or net drum. In FIG. 2, the yarns T taken up from the traction rollers 10 
with the air jetting device 4 are projected onto the lattice or net drum 
5, whereby the yarns T are separated from the air stream, and only the 
yarns T are received into the receiving device 1. However, this method 
also has defects in that when the yarns are projected onto the drum, the 
yarns become somewhat crimped and entangled, and therefore, when the yarns 
are drawn out from the receiving device in a subsequent step, the yarns 
can not stably be drawn out because they have become snarled. Furthermore, 
the received yarns have a small bulk density which requires the employment 
of a larger receiving device. 
FIG. 3 is a front view of a conventional take-up apparatus using an air 
jetting device and a baffle plate wherein the yarns are separated from the 
air stream by moving the yarns in a reverse direction. In FIG. 3, the 
yarns T discharged from the nozzle 6 of a melt spinning machine are hauled 
with the traction rollers 2, wherein the winding of the yarns onto the 
traction rollers 2 is prevented with the air jetting device 4, and the 
yarns T discharged from the air jetting device 4 are projected onto the 
baffle plate 7, are moved in a reverse direction and are received into the 
receiving device 1, wherein the air stream separator 8 and the shoot 9 are 
employed. This method is described, for instance, in Japanese patent 
publication No. 1287/1966. According to this method, for preventing the 
entanglement and disturbance of the yarns due to the jetting air stream 
discharged from the air jetting device together with the yarns, the high 
speed stream of the mixture of the yarns and the jetting air is projected 
onto the baffle plate 7 provided obliquely to the stream direction of the 
yarns and air and thereby moved in the reverse direction. Thereafter the 
yarns fall by their own weight, separating the yarns from the air stream. 
However, according to this method, when the multifilament yarns are 
projected onto the baffle plate, the adjacent yarns interfere with each 
other and therefore the disturbance of the yarns cannot sufficiently be 
prevented. Moreover, when the yarns are thick, such as tow, the reverse 
motion of the tow is very difficult. 
According to the present invention, the defects in these conventional 
methods can be eliminated. FIG. 4 is a schematic front view for 
illustrating the whole apparatus of the present invention. In FIG. 4, the 
final take-up rollers 10 for taking up the yarns is rotated at a speed 
similar to the yarn take-up speed, for instance at 2,000 m/min. As the 
final take-up rollers, a single roller may be employed, or a pair of 
rollers as shown in FIG. 4 may be employed for decreasing the amount of 
the air supplied in the air jetting device. In the air jetting device 4, 
air is introduced under pressure from the inlet 19 and the yarns T are 
drawn down together with the jetting air stream and thereby the winding of 
the yarns onto the rollers 10 is prevented. The yarns T and the air stream 
discharged from the outlet of the air jetting device 4 are led into the 
inlet 12 of the bent tube 13 with the guide pipe 11. In the bent tube 13, 
the yarns T and the air stream led into the inlet 12 are passed through 
the bent tube 13 without a decrease of the flow speed, and then are 
discharged from the outlet 14 of the bent tube, during which the bent tube 
13 is by the driving motor in substantially reverse direction to that of 
the yarns T and the air stream discharged from the outlet 14 of the bent 
tube at a peripheral speed of the outlet 14 of 0.5 to 2.0 times, 
preferably 0.8 to 1.3 times that of the yarn take-up speed. By this 
operation, the yarns T and the air stream are discharged from the outlet 
14 of the bent tube 13 at an absolute speed of approximately zero 
(relative to the surface of the earth). Accordingly, the yarns T are not 
disturbed by the air stream and thus fall in a stable, coil form 15. The 
yarns which fall in the coil form are received in the yarn receiving 
device 1 without any entanglement of the yarns in a state of high bulk 
density. More preferably, the receiving device 1 is rotated or 
reciprocated while receiving the yarns. 
When the rotating speed of the outlet 14 of the bent tube 13 is over 2.0 
times the yarn take-up speed, the yarns T passed through the bent tube 13 
are pulled with the bent tube 13, and thereby, the received yarns are 
moved in the receiving device 1, which causes the entanglement of the 
yarns. On the other hand, when the rotating speed of the outlet 14 is less 
than 0.5 times that the yarn take-up speed, the yarns and the air stream 
have a fairly large absolute speed and the yarns are disturbed while the 
speed is decreased with the air resistance, and therefore, the received 
yarns have a small bulk density, which requires the employment of a larger 
receiving device. The yarn take-up speed is preferably 2,000 m/min. or 
more, and is usually from 2,000 to 6,000 m/min. 
FIGS. 5 and 6 show one embodiment of the device for driving the bent tube, 
and FIG. 5 is a sectional front view thereof and FIG. 6 is a plane view 
thereof. The bent tube 13 is supported with the bearing 17 and is rotated 
with the motor 16 via the belt 18. The bent tube is bent in the radial 
direction toward the tip thereof and in the tangential direction, and the 
outlet 14 is opened in the tangential direction. Besides, it is preferable 
that the outlet 14 is opened in an angle of about .+-. 50.degree. against 
the horizontal direction, and is more preferably opened downward in an 
angle of 15.degree. to 45.degree. against the horizontal direction. The 
bent tube is preferably made of steel or porcelain and has a smooth inner 
surface. Moreover, the bent tube is preferably connected in one piece with 
the cylindrical cover 20 at the bent section of the bent tube. Said 
cylindrical cover 20 functions as the balance weight and is useful for 
inhibiting the rotating air stream. 
The present invention is illustrated by the following Example, but is not 
limited thereto. 
EXAMPLE 1 
Polyethylene terephthalate having an intrinsic viscosity of 0.63 (measured 
in a mixed solvent of phenol/tetrachloroethane = 6/4, at 30.degree. C) is 
melt-spun through a spinneret (number of holes: 2,000), and the spun 
filaments are cooled and solidified by blowing them air stream at room 
temperature at just below the spinneret. The filaments are treated with an 
oiling agent and then taken up with the first rollers at a speed of 3,200 
m/min. and led to the bundling rollers, during which the moving direction 
of the filaments is controlled. Eight filaments thus obtained by the high 
speed spinning are bundled, and the yarns thus produced are led to the 
final take-up rollers which are rotating at a peripheral speed of 3,200 
m/min. The yarns are passed through the air jetting device and the 
rotating bent tube and then received in the cylindrical can, as shown in 
FIG. 4. The outlet of the bent tube used therein is opened downward in an 
angle of 25.degree. against the horizontal direction, and the rotating 
radius is 15 cm and the peripheral speed of the outlet is 3,500 m/min. The 
can is rotated by the supporting rotating circular plate so that the yarns 
are uniformly received in the spiral form in the can. 
The received yarns are tightly packed in the can (the bulk density: 200 
kg/m.sup.3), and when the yarns are drawn out for the orientation thereof 
in the subsequent step, the snarl of the yarns is observed only one time 
per 100,000 m. 
For the comparison purpose, according to the conventional methods as shown 
in FIGS. 1 and 2, the same yarns as used in the above Example 1 are 
received in the receiving can at a take-up speed of 3,200 m/min. As the 
results, in case of using the gear rollers as shown in FIG. 1, the yarns 
are frequently wound onto the gear rollers and it is impossible to 
continue the operation. Besides, in case of the method as shown in FIG. 2, 
the yarns are loosely packed in the can (the bulk density: 70 kg/m.sup.3), 
and when the yarns are drawn out for the orientation thereof in the 
subsequent step, the snarl of the yarns is frequetly observed, i.e. one 
time per 1,000 m, which is remarkedly inferior to the method of the 
present invention.