Apparatus for moistening and texturing yarns

Apparatus for moistening and texturing yarns is described wherein yarns travel side-by-side over a surface into which bores, one for each yarn, open. Water under low pressure is delivered through the bores, the diameters of which are so adapted to the titers of the yarns that the yarns travelling over the bores exert a suction effect on the water and carry the water between the filaments in each yarn, without any additional layer of water enclosing the yarn, to a texturing nozzle. While passing through the nozzle loops or convolutions are formed in the individual filaments of the yarns by compressed air blown into a whirling chamber in the nozzle. The air is discharged from the nozzle, carrying the water away with it at the same end as the textured yarn, now substantially dry and formed from the non-textured yarns, emerges from the nozzle. The surface which is convexly curved and the bores with an inlet channel common to them are formed on a plug that fits into a holder connected by a tube to a water container.

FIELD OF THE INVENTION 
The present invention relates to an apparatus for moistening and texturing 
one or several yarns consisting of a plurality of synthetic filaments or 
of native fibers or of mixtures of both. 
DESCRIPTION OF THE PRIOR ART 
In the textile industry, recently, to an increasing extent, not only yarns 
of natural materials, such as for example wool or cotton, but also of 
synthetic material, are used, the yarn consisting of a plurality of 
endless synthetic filaments which lie parallel to each other in the yarn. 
Various methods are known by which a wool-like character can be imparted to 
such synthetic yarns by bulking them, i.e. by increasing their volume. For 
this purpose, it is known to use a so-called texturing nozzle through 
which the yarn is passed at an overfeed corresponding to the desired 
degree of texturing; the nozzle comprises a whirling chamber which is fed 
with a medium under pressure, for example air, to form loops and 
convolutions in the yarn by which the volume, i.e. the cross-section of 
the yarn, is enlarged and a wool-like character is imparted thereto. Such 
texturing nozzles are known in many embodiments. They always consist of a 
guiding channel for receiving the yarn to be textured which is followed by 
a whirling chamber in which loops or convolutions are formed in the yarn 
by the compressed air so that the textured yarn issuing from the whirling 
chamber has a volume enlarged due to loop formation. The yarn textured in 
this manner in the whirling chamber is carried out of the whirling chamber 
and removed by the air current to be wound up on a bobbin before being 
handed on for further processing. 
It has been found that the formation of the loops or convolutions can be 
improved and accelerated optimally if the yarn to be textured is moistened 
with a liquid, usually water, before being fed to the texturing nozzle. 
Because of the more rapid formation of the loops or convolutions in 
moistened yarns, the texturing in the whirling chamber of the nozzle is 
effected in an essentially shorter time as a consequence of which the 
texturing nozzle can be operated with at least double the passage speed of 
the yarn. 
In order to impart the necessary moistening to the yarn to be textured, 
consisting of synthetic filaments, it is known to arrange a liquid 
container upstream of the nozzle by which the yarn, before entering into 
the texturing nozzle, is passed so that it enters into contact with the 
water contained in the liquid container. For this purpose, the yarn is 
deviated over guiding bars at an acute angle, the vertex of which is 
formed by a guiding bar situated below the level of the water bath. This 
guiding of the yarn through the water bath is disadvantageous insofar as 
the yarn excessively absorbs water. Not only the spaces existing between 
the individual filaments of the yarn are filled with water, but cohesion 
causes the formation of an additional layer of water enclosing the yarn, 
which must be removed before the yarn enters the nozzle. This is effected 
on the one hand by detaching a part of the excessive water at the 
deviation elements provided upstream of the texturing nozzle, by 
projecting the water away and on the other hand by causing a further part 
of the excess of water to be poured away in the narrower guiding channel 
situated upstream of the whirling chamber. Since the guiding channel in 
the nozzle, for easily understandable reasons, must have a larger although 
only slightly larger, diameter than the yarn, always a remainder of the 
excessive water reaches the whirling chamber wherein it is detached by the 
current of air and must be removed from the whirling chamber together with 
the air. This excess of water has therefore disturbing effects outside the 
nozzle as well as in the whirling chamber and leads to excessive water 
precipitation on the apparatus used for yarn treatment. 
SUMMARY OF THE INVENTION 
It is the purpose of the present invention to avoid the above-mentioned 
disadvantage in a device including a texturing nozzle and a liquid 
container arranged upstream of the nozzle, intended for moistening the 
yarn, and to dispose and form the liquid container serving to moisten the 
yarn in such a manner that, during moistening the yarn, the absorption of 
an excess of water is avoided and that the yarn only absorbs enough water 
in the wetting device to fill the spaces existing beween the individual 
filaments of the yarn with water, while the formation of a coating of 
water enclosing the yarn, which must be removed again, is avoided. 
According to the present invention, this problem is resolved by a liquid 
container having a member the surface of which defines the path of the 
yarn, the front surface of the member comprising a number of bores over 
which the yarns pass and which corresponds to the number of yarns to be 
fed to the nozzle, the bores being fed with liquid from the liquid 
container, and their diameter being so adapted to the titer of the yarns 
that the yarns passing over the bores exert a suction effect on the liquid 
in the bores. Due to the fact that each travelling yarn is guided over a 
bore situated upstream of the texturing nozzle and is fed from the water 
container, the bore being adapted to the titer of the yarn, the direct 
contact with a water bath that has been necessary up to now is avoided, 
and the travelling yarn, due to the suction effect produced by its 
movement, only absorbs enough water from the bore for the spaces between 
the filaments of the yarn to be filled with water, without the possibility 
of an additional coating of water being created around the yarn. In this 
manner, projection or stripping-off of excessive water from the yarn 
before it enters the texturing nozzle is avoided, and only the water 
absorbed between the filaments of the yarn is removed in the whirling 
chamber by blowing off the water. Therefore the textured yarn emerges from 
the texturing nozzle substantially dry. 
Advantageously the level of the liquid in the container is sufficiently 
high for the liquid fed to the bore to be under slight static pressure. 
The low static pressure under which the water is presented to the surface 
of the member over which the yarn passes, ensures that disruption of the 
water film in the bore by the suction effect of the yarn is avoided and a 
continuous and uniform wetting of the yarn results. This static pressure 
depends on the kind and the travelling speed of the yarn and may, as a 
rule, amount to between 10 and 100 mm water gauge. 
Very conveniently the yarn may be guided centrally over the bores by means 
of guiding bars disposed on both sides of the bores. The guiding bars 
ensure that each yarn is always guided centrally over its respective bore 
without any fluttering movements, whereby uniform wetting is assured. 
It is convenient for the bore or each bore to lead from a wider channel in 
the said member. If several yarns consisting of filaments are 
simultaneously processed in the texturing nozzle, the bores associated 
respectively with the yarns lead from the front face of a common channel 
whereby an equal distribution of water to all the bores is ensured. 
The said member may be in the form of a plug which can be fitted and sealed 
into a holder connected to the liquid container. The shaping of the plug 
as a removable fitting makes it possible to change the member easily if 
the number of yarns (for example one, two or three) to be fed to the 
texturing nozzle simultaneously is to be altered. 
It is highly desirable for the plug to have a convexly curved front surface 
which, if necessary, may be provided additionally with a thread-guide 
groove. The yarn to be textured is guided by the convex curve of the front 
surface over the bore practically without deviation and without danger of 
damage. 
It is furthermore important that the plug should consist of non-corrosive 
material. This measure prevents the bore in the front surface of the plug 
from being obstructed by corrosion. 
Obviously also the front surface of the plug should be wear-resistant. 
Therefore, the front surface of the plug may be coated with a 
wear-resistant coating which prevents the travelling yarn from cutting 
into the front surface of the plug.

Referring to the drawings, in a support plate 1, a known air texturing 
nozzle 2 is provided, the whirling chamber of which is fed with compressed 
air through a bore 3 inclined so that the air is discharged at one end of 
the nozzle. Referring to FIG. 2, in the texturing nozzle 2, two yarns 6, 7 
are simultaneously textured, these yarns being fed to the nozzle 2 by 
delivery devices 4, 5 with overfeed. The yarn leaves the nozzle at the 
same end as the air stream. 
Upstream of the texturing nozzle 2, there is provided a deviation pin 8 
over which the two yarns 6, 7 are introduced into the nozzle. A yarn 25 
formed of the two yarns 6, 7 is removed from the texturing nozzle 2 by way 
of a guiding element 9 and fed to a bobbin (not shown). The deviating pin 
8 and guiding element 9 are rotatable around an axis 10 so that they can 
be adjusted exactly centrally with respect to the texturing nozzle 2. 
On the plate 1, there is arranged, ahead of the texturing nozzle 2, a 
holder 11 which is connected by a tube 12 with a liquid container 13 
containing water. At its front end, the holder 11 is formed with a bore of 
enlarged diameter into which a plug 15 can be inserted which has a 
convexly curved front surface 16. The plug has a sealing ring 26 so that 
it can be inserted tightly into the bore 14 of the holder 11. On the front 
surface 16 of the plug 15, there are arranged two bores 17, 18 beside each 
other over which the yarns 6, 7 pass. The bores 17, 18 lead from a common 
channel 24 in communication with the tube 12. In order to ensure exactly 
centrical guiding of the yarns 6, 7 over the bores 17, 18, a plate 19 on 
which two guiding pins 20, 21 are fixed, is arranged above the holder 11. 
By means of an adjusting element 22, the guiding pins 20, 21 can be 
adjusted so that the yarns guided over the deviation pin 8 respectively 
pass centrally over the bores 17, 18 in the front surface 16 of plug 15. 
In the water container 13, the water level 23 is adjusted so that the 
water in the bores 17, 18 is under low static gauge pressure (10 to 100 mm 
water gauge). The front surface 16 of the plug 15, as particularly shown 
in FIG. 1, so engages the yarns 6, 7 that they are maintained in contact 
with the front surface 16. 
The diameters of the bores 17, 18 are so adapted to the titers of the yarns 
passing thereover that when the yarns 6, 7 are fed to the texturing nozzle 
2, they absorb a quantity of water because of the suction effect due to 
their speed over the bores 17, 18. The spaces between the filaments of the 
yarns 6, 7 are thereby filled with water but without any additional layer 
of water enclosing the yarn. The low static gauge pressure on the water in 
the bores 17, 18 results in uninterrupted feeding of the water. The yarns 
6, 7 moistened by water from the bores 17, 18 enters the texturing nozzle 
2 after passing partially round the deviation pin 8. In the texturing 
nozzle, loops or convolutions in the individual filaments of the yarn 6, 7 
are formed by compressed air fed into the whirling chamber and the 
compressed air blows the water off the loops or convolutions through the 
texturing nozzle 2, the water being removed with the compressed air 
leaving the texturing nozzle in the direction of the yarn travel so that, 
beyond the texturing nozzle 2, a dry, textured yarn 25 is formed from the 
non-textured yarns. 
The surface 16 may be formed with grooves for the yarns and the plug 15 is 
made of non-corrosive material and may be made wear-resistant for example 
by chromium-coating or by tempering.