EP0202197B1

EP0202197B1 - Method and apparatus for the manufacture of spools filled with indigo dyed weft yarn

Info

Publication number: EP0202197B1
Application number: EP86810213A
Authority: EP
Inventors: Moritz Wälti; Geremia Carminati; Stefan Aggeler
Original assignee: INDUSTRIAL PROCESSES AND RESEARCH BV
Current assignee: INDUSTRIAL PROCESSES AND RESEARCH B.V.
Priority date: 1985-05-15
Filing date: 1986-05-14
Publication date: 1989-08-09
Also published as: DE3664897D1; JPS61266634A; ATE45330T1; EP0202197A1; ES8800649A1; ES554934A0

Abstract

Methods and machines for obtaining weft yarns on weaving spools are described and claimed. These yarns are cotton threads which are real indigo dyed and principally destined for the weaving of blue-in-blue denim. The weft yarns are obtained from warp yarns by special rebeaming and isolating steps. A new flanged weaving spool is made by injection molding and comprises two geometrically similar halves cemented together.

Description

Background of the invention

Field of the invention

This invention principally belongs to the technical field of textile fabric weaving. More particularly, it is related to a new and useful method to prepare weft yarn spools filled with indigo dyed yarns, in order to supply weft yarn to a conventional weaving loom. The invention further con- cems a new and useful apparatus to implement the method of this invention.

Description of the prior art

Indigo dyed fabrics are well known, and they have acquainted an extraordinarily wide use in garments such as « blue jeans made of « real indigo » denim. The man skilled in the art is well informed of the fact that such « real indigo denim cannot be made in dyeing an already woven fabric with indigo vat dyestuff since the « real indigo has certain specific and intrinsic wear properties which are greatly desired and which are inseparately linked to its special mode of manufacture.
This manufacture comprises, as it is familiar to the man skilled in the art, the indigo dyeing of warp yarns, be it in the so-called slasher dyeing process or in the chain-dyeing process, and the weaving into denim with undyed or bleached cotton threads as weft yams.
Undyed weft yarns had to be used, since it has not been technically possible, until now, to get indigo dyed weft yarns from the above mentioned indigo dyed warp yarns, and since it is not possible to dye yarns which are wound up on spools, in dyeing apparatuses with indigo vat dye. These facts are well known to the one skilled in the art.
However, there is a strong need for denim fabrics wherein the weft yarns are « real indigo dyed. Of course, it is not impossible to provide weft yarns which are dyed with non-vat dyestuffs, such as a naphtol dyestuffs, but the customer does not accept the fabrics otherwise dyed as with indigo, and there is a strong need for denim garments and apparel made from « blue-in-blue » real indigo denim, i. e. from denim where the warp yarns as well as the weft yarns are dyed with indigo vat dyestuff.
The prior art does not disclose the problem of making weft yarn which is indigo dyed.
U. S. patent no. 2,889,120 describes and claims a machine for winding a series of sewing machine bobbins or self-sustaining cops. British patent specification no. 340,978 describes a warp beam for the treatment of artificial silk. British patent specification no. 645,591 teaches improvements in sectionalized yarns beams for warp yarns. Still other publications describe the winding of other mechanical treatments of warp yarns.
No publication puts forward the problem of providing indigo dyed weft yarn nor teaches any method for obtaining weaving bobbins of such weft yarn.

Objects of the invention

Therefore, it is the first and principal object of this invention to provide a method to manufacture weft yam spools filled with indigo dyed yarn, wherein the weft yarn is dyed with real indigo and which are ready to be used in weaving looms to produce, together with indigo dyed warp yarn, for example real indigo blue-in-blue denim.
Another object of the invention is to provide a method as set forth above which allows an economical work free from time consuming breakdowns, for example due to yarn ruptures, and free from avoidable wastes.
Still another and equally significant object of this invention is to provide a simple but perfor- mant apparatus which allows to implement the new method and which produces weft yarn loom spools filled with indigo dyed yarn, in excellent yields and without substantiel waste.

Summary of the invention

The invention allows for the first time to produce weaving loom spools wherein an indigo dyed weft yarn is wound on flange bobbins or disk spools. The basic idea of the invention is to collect a weft yarn from indigo dyed warp yarns.
The dyeing of warp yarns with an indigo vat is known per se, see, e. g. Swiss patent specifications nos. 612, 557 and 613, 333 and the article by P. Richter in « Textilveredlung », 1975, pp. 313-317. These publications teach that warp yarns may be indigo dyed in one of two processes called « chain dyeing » and « slasher dyeing », respectively.
The chain dyeing comprises the forming of yarn cables from about 300 to 400 individual warp yarns, and several cables are dyed simultaneously and in horizontal relationship to each other in the indigo vat liquor, air passages of the cables for the oxidation of the indigo being introduces between sequential vat passages. The cables are then rinsed, dried and warped. On the warp bobbins, there are lengths of about 10'000 m of a yarn cable each.
In the « slasher dyeing method, several thousand yarns are arranged in horizontal relationship to form a sheet-like structure, this « sheet is dyed as explained above, and finally as much warp beams are used as there were superimposed yarn sheets whereon these sheets are wound in the form of a weaving chain each.
The above-mentioned basic idea of the inventors, namely to collect a weft yarn from dyed warp yarns, was very difficult to put into practice since it is not possible to process the wound packages on the bobbins, obtained according to the shlasher dyeing process, so as to obtain winding of single yarns on weaving spools.
It has now been found that these difficulties can be obviated, and individual weaving spools filled with indigo dyed weft yarns can be manufactured starting from windings of warp yams on a warp beam, if, according to the invention, individual yarns are separated from warp yarn layers according to the process defined in independent claim 1. Embodiments of this process are the subject of dependent claims.
In the slasher dyeing method, the dyed yams are beamed on a warp beam in the future warp ccnfiguration, i. e. in the form of several thousands of parallel warp yarns wound up in succeeding « layers ». The invention has the object to develop weft yams from this winding too.
This object may be attained, according to the invention, by introducing additional yams, in the amount necessary for the weft, into the set of warp yarns before the dyeing step, to recover them after the dyeing, and to wind them up, separately from the warp yams but simultaneously and, of course, with the same speed. Another embodiment of this method is to form the warp beam as described above, without separating the weft yams, and to recover the weft yams on the said flanged weaving spools during a subsequent rebeaming of the original warp yarn beam obtained after the dyeing step, said rebeaming and recovering of weft yarns may be effected twice or even more often.
This method has been been developed from the finding that there is in the slasher dyeing no substantial entangling of the yarns, and that the relatively slow working speed which is dictated by the highest possible dyeing speed prevents a subsequent entangling of the yarns on the warp beam under formation.

Brief description of the drawing

The invention will still better be understood and objects other than these set forth above, will become apparent when consideration is given to the following detailed description thereof, making reference to the annexed drawing wherein :

Figure 1 is a schematical side view of a system for the simultaneous indigo vat dyeing of warp and weft yarns following the slasher dyeing principle ;
Figure 2 is a schematical side view of a rebeaming system for the recovery of weft yarns from warp yarns being wound up on a warp beam ; and
Figure 3 is a central sectional view of a flanged weaving spool.

Figure 1 shows schematically a side view of a system for the indigo dyeing of warp yarns following the principle of the slasher dyeing, however comprising means for the separate manufacture of weft yarns. The drawing is most simplified and is only intended to show the general procedure of this invention.
The indigo dyeing machine is designed as 60 and the subsequent devices for washing, optional aviving and drying are designed as the field 62. The warp yarn to be dyed is typically unwound from the warping beams 64 and 66. Then the warp yarns are combined, dyed, worked up and divided and separately wound up on two weaving beams 68 and 70. This method is known, see for example the Swiss Patent specification no. 612, 557 already mentioned above. According to this invention, a further yarn beam 72 is provided which supplies weft yarns in such a manner that the horizontal distance between two weft yarns is about 50 mm. These weft yarns are now treated together with the warp yams in the machine 60, 62, are separated when leaving the machine, by the device 73 from the upper warp yarn layer 74, and finally wound up separately on flanged weaving spools 42. These weaving spools 42 can thus immediately be used without rebeaming, as a weft yarn supply.
The weft yarns may also be provided with lesser horizontal distance. For space economic reasons, the number of weft yarns should not exceed three times the number of the flanged weaving spools on the spool shaft. In this case, deflecting means must be used, for example eyelet bars (not shown).
Finally, figure 2 schematically shows a side view of a device for providing weft yarns from warp yarns.
The warp beam 80 comprises warp yarns which have previously been indigo dyed. in a slasher dyeing machine. The parallel yam layer 82 is now rebeamed in the direction shown by arrows 84, goes about deflecting rollers 88, 90 and 92, and is wound up on the empty beam 86. The driving and spreading means are not shown in these Figure. On the way described, individual threads are removed by separating rollers 43 and wound up on flanged weaving spools 42 which are fixed on ten shafts 44. The number of the individual threads thus removed (E) is therefore a total of
if B is the width of the yarn layer 82 and b that of the weaving spool. When the content of the beam 80 will have been rebeamed on the body 86, the number of weaving spools will be E. Then, fresh weaving spool shafts 44 having empty weaving spools 42 are inserted, and the remaining thread layer on the beam 86 is rebeamed on beam 80, now empty, in the direction of arrows 94. This work is continued until all threads on the beams 80 and 86 will be transferred to the weaving spools 42.
There are for example 32 spools 42 fixed side by side on the shaft 44. The shaft 44 is driven by a hydraulic motor (not shown). For each spool 42, a winding force of about 70 N (when yams with a titer of about NE 12 are used) is maintained ; the hydraulic motor should therefore provide a constant torque.
Each flanged weaving spool 42 receives for winding an individual yarn whose length is about 10 000 m. The winding up is preferably begun in pinching the leading end of yarn between two flanges of adjacent spools. This beginning is the trailing end when the spool will be filled. This trailing end is therefore, directly accessible and can be joined to the normal leading end of the next weaving spool so as to avoid any interruption during the weaving process.
Figure 3 shows a central sectional view of a flanged weaving spool used in the method of this invention.
The spool 42 is composed of two parts which are preferably each manufactured by injection molding from a thermoplastic synthetic resin, namely the inner portion 52 and the outer portion 54. The dimensions of the radial flanges and the axial hub are selected so that the shape represented in Figure 3 is obtained when the two portions are put together ; then, the two portions 52 and 54 are cemented together with the cylindrical contact surfaces 56 and 56' and form thus a compact and a solid spool body.
The solutions of the objects of this invention may be modified in the frame of equivalents. For example, the described hydraulic motors of the flanged weaving spool shaft may be replaced by other driving means, for example controlled by electronic means. Additional and complementary means of the described devices are not always described or shown in the drawing since these additional means are normally known to the man skilled in the art.

Claims

1. Process for obtaining an indigo dyed cotton weft yarn wound up ready for weaving on weft yarn spools, wherein the yam is indigo dyed according to the slasher dyeing method as at least one yarn layer made of a plurality of parallel individual threads, characterized by the fact that individual threads are separated from said at least one yam layer after the dyeing step, and that the said threads are individually wound up as weft yarns on weaving spools which are arranged on a common beam in side-by-side relationship, whilst the remaining yarn is beamed as warp yams.

2. The process of claim 1, characterized by the fact that a layer made of a plurality of parallel and mutually spaced individual weft yams is dyed together with at least two superimposed dense warp layers each formed by a plurality of parallel warp yarns, that the said layer of weft yarns is separated, after dyeing, from said layers of warp yarns, and that the weft yarns are separately and individually wound up on said weaving spools.

3. The process of claim 1, characterized by the fact that a dyed cotton warp yarn, wound on a warp beam as windings of dense yam layers each formed by a plurality of individual, parallel yarns, is unwound from said warp beam as a dense yarn layer and rewound on a second warp beam, and that a predetermined number of individual yarns is separated during said rewinding step from the warp yarn layers and coiled separately as a weft yarn on said weaving spools.

4. Apparatus for carrying out the process of claim 1, characterized by supply spools (64, 66, 72 ; 80) comprising windings of layers of yarn each formed by a plurality of individual, parallel yarns, at least one warp yarn beam (68, 70 ; 86), means (43 ; 73) for separating weft yarns from travelling warp yarn layers, and at least one set of weft yarn weaving spools (42) in side-by-side arrangement and blocked together on at least one horizontal shaft (44).

5. The apparatus of claim 4 for carrying out the process of claim 2, further comprising a weft yarn supply (72), means for combining said warp and weft yarns, and means (73) for separating said weft yarns from said warp yarns.

6. The apparatus of claim 4 for carrying out the process of claim 3, characterized by a device for unwinding a dense layer (82) of indigo dyed warp yarns from a warp beam (80), means (43) for separating a predetermined number of individual yarns from said dense yarn layer (82), a device for individually winding up said separated yarns as weft yams, comprising a plurality of horizontal shafts (44) each carrying weaving spools (42) in side-by-side arrangement, and a device for rewinding the remaining warp yarns on a receiving beam (86).

7. The apparatus of claims 4 and 6, characterized by the fact that said horizontal shaft (44) is fitted with a constant torque center driving means.

8. The apparatus of claim 7, characterized by the fact that said center driving means is a hydraulic motor.