Apparatus for continuous dyeing of yarns

Abstract

The apparatus for continuously dyeing a yarn includes a plurality of U-shaped dye applicators angularly offset from each other about the axis of the yarn and each having a dye discharge aperture for discharging a dye onto said yarn.

Parent Case Text

This is a division of application Ser. No. 262,846, filed June 14, 1972, and now U.S. Pat. No. 3,808,618.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for continuously dyeing various forms of yarns of synthetic fibers, natural fibers or a mixture of these fibers, such as filament yarns, spun yarns or crimped yarns, at high speed, and especially to an apparatus suitable for dyeing these yarns in multicolors.

2. Description of the Prior Art

It has previously been a wide spread practice to dye yarns in the form of skeins or packages such as cheese or cone in order to obtain uniform dyeing, and a number of apparatuses used for this dyeing are known. One of the prior methods of continuously dyeing yarns comprises dipping a yarn in a dye bath while passing it therethrough, removing the excess dye liquor from the yarn using nip rollers to adhere a prescribed amount of the dye liquor to the surface of the yarn, and then heating the yarn to effect dye exhaustion. Another method involves bringing a yarn into contact with a revolving roller partly immersed in a dye bath to transfer the dye liquor on the roller to the yarn, and then heating the yarn. The former method has the disadvantage that the yarn tends to become flattened when held by the nip rollers, and it is difficult and inefficient to revolve the nip rollers at high speed yet to squeeze the yarn uniformly. According to the latter method, the dye liquor is scattered when the roller for applying the dye is rotated at high speed, and therefore it is difficult to dye the yarn at high speed.

The methods generally known to dye intermittently colored yarns or multicolored yarns include, for example:

1. A method in which a part of a skein is dyed by immersion in a dye bath, and then another part of the skein is dyed by immersion in a dye bath of a different color.

2. A method disclosed in U.S. Pat. No. 3,218,654 in which running yarn is vibrated and brought into intermittent contact along its length with a revolving roller partly immersed in a dye bath to transfer the dye liquor intermittently to the yarn, followed by a heat-treatment to effect dye exhaustion.

3. A method in which a running yarn is contacted intermittently with a mechanically operated dye applicator which is reciprocatingly moved over a small distance, thereby to transfer the dye liquor intermittently to the yarn, followed by a heat-treatment to effect dye exhaustion.

4. A method in which a yarn is knitted, and a desired pattern is printed on the resulting knitted fabric. The fabric is then treated with steam or a dry heat to fix the dye then the fabric is deknitted.

However, these methods have various disadvantages. In method (1), it is difficult to obtain a yarn having a dyed portion of a short length because of the necessity for immersing a part of the skein in a dye bath, and moreover, the productivity of this method is low. According to method (2), the tension of the yarn becomes non-uniform, and yarn breakage tends to occur. Method (3) has the disadvantage that it is difficult to operate the dye applicator at high speed, and at high speed, the dye liquor scatters. According to method (4), fuzzes or fluffs tend to occur during the knitting and deknitting operations, and moreover, the productivity of this method is low.

It is an object of this invention to provide an apparatus for dyeing yarns, which is free from the above described disadvantages of the prior art.

It is another object of this invention to provide an apparatus for continuously dyeing yarns in desired forms composed of various fibrous materials at very high speed.

It is still another object of this invention to provide an apparatus for obtaining intermittently colored yarn or multicolored yarn.

SUMMARY OF THE INVENTION

The present invention provides an apparatus for continuously dyeing a yarn. The apparatus comprises means for heating a running yarn to a temperature above the boiling point of a solvent in a dye and dyeing the yarn by contacting the yarn with one or more dyes discharged from a plurality of dye applicators each having an aperture for discharging the dye.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing one embodiment of this invention.

FIG. 2 is a perspective view of a dye applicator 5 shown in FIG. 1.

FIGS. 3A and 3B are views illustrating the use of two dye applicators, FIG. 3A showing their arrangement on opposite sides of the yarn, and FIG. 3B showing their arrangement on the same side of the yarn.

FIGS. 4 and 5 are sectional views of the yarns obtained by the method of this invention.

FIG. 6 is a side elevation of the yarns obtained by the method of this invention.

FIG. 7 is a sectional view of one embodiment of a means for discharging the flow of dye intermittently.

FIG. 8 is a sectional view of the principal parts of one dye applicator device from which three different dyes are discharged.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a yarn 2 is unwound from a cone 1, passed over a guide roller 3, heated by a heater 4, and then contacted with a dye applicator device 5. A dye is applied to the yarn 2 using this dye applicator 5. The dye is stored in a tank 6, and supplied to the dye applicator 5 by a metering pump 7. The dye is then discharged from a small aperture provided in the applicator 5. After application of the dye, the yarn 2 is dried in a dryer 8, passed over a guide roller 9, and is taken up on a winder 10.

The details of the dye applicator device 5 in FIG. 1 are shown in FIG. 2. In FIG. 2, the reference numeral 13 represents a U-shaped groove through which the yarn 2 runs in contact therewith. A dye discharge aperture 11 is provided near the central portion of the bottom of the U-shaped groove. The dye which is supplied through a pipe 12 is discharged from this aperture in the appropriate amount, and applied to the yarn 2 which is running through the groove 13 in contact with the bottom of the groove including the discharge aperture 11. The diameter of the dye discharge aperture and the opening angle of the U-shaped groove differ somewhat according to the thickness of the yarn to be dyed. Generally, however, it is desirable that the diameter of the discharge opening ranges from about 0.1 to 1 mm, and the opening angle of the groove through which the yarn passes ranges from about 15.degree. to 145.degree..

In FIG. 1, only one dye applicator device is shown. By providing two or more dye applicators, it is possible to dye a yarn with more than one color. The use of two applicators is illustrated in FIG. 3.

Referring to FIG. 3A, the running yarn 2 comes in contact with one of the dye applicators 5, and the dye is applied to one side of the yarn from the aperture 11. This yarn then comes in contact with the other applicator device 5' disposed opposite to the applicator 5, and a dye the same color as or a dye a different color from that applied by the applicator 5 is applied to the opposite side of the yarn 2. When different dyes are applied, the yarn is dyed in two colors as shown sectionally in FIG. 4, and the two colors are separately continuous along the length of the resulting yarn. FIG. 3B illustrates the arrangement in which two dye applicator devices 5, 5' are provided on the same side of the running yarn, in which the same or different dyes can be applied to the yarn from the respective discharge apertures in the applicator devices. Likewise, when three applicator devices are provided around the yarn, the yarn can be dyed in three colors as shown in FIG. 5. When such a yarn is used for conventional knitting or weaving, torsion occurs in the yarn during the knitting or weaving process, and therefore, a random colored fabric is obtained as a result of the weaving or knitting.

Various multicolored yarns as shown in FIG. 5, A, B and C can be obtained by changing the amount of the dye or the position of the dye applicator, as desired. FIG. 5A illustrates a section of a multicolored yarn obtained by discharging small amounts of the dye. FIG. 5B shows a section of a multicolored yarn in which two adjoining colors are mixed with each other as a result of discharging large quantities of the dye. FIG. 5C shows a section of a multicolored yarn which contains undyed portions as a result of arranging the dye applicators around the yarn at unequal intervals.

When a yarn is dyed using one or more of the dye applicators shown in FIG. 2, it is possible to obtain variously dyed yarns by changing the amount of the dye discharged. Thus, the yarn can be uniformly dyed similar to conventional dip dyeing, or it can be dyed randomly to obtain a yarn having intermittent dyed portions along its length, i.e., intermittently colored yarn or to obtain multicolored yarns. For example, when the dye is continuously discharged from the aperture of the dye applicator, it is possible to obtain a yarn having a continuous dye portion along its length as shown in FIG. 6A. If, on the other hand, the dye is fed intermittently and discharged, a yarn colored intermittently along its length can be obtained as shown in FIG. 6B. Any desired means can be employed to obtain an intermittent flow of the dye. One method involves the incorporation of air bubbles in the dye. For example, an air pump can be provided somewhere in the pipe for feeding the dye in order to introduce air bubbles thereinto. By changing the amount of air bubbles fed by the air pump, the distances between the colored portions can be varied as desired. In order to prepare very fine bubbles, a gas such as air or carbon dioxide gas is dissolved under pressure in the dye and the bubbles of these gasses may be generated in the dye in the vicinity of the discharge openings where the pressure approaches normal atmospheric pressure. Or these gasses dissolved in the dye may be converted into bubbles by heating in the vicinity of the discharge openings. Alternatively, a chemical generating a gas upon heating, such as sodium bicarbonate, can be incorporated in the dye, and by heating it near the discharge openings, bubbles are generated.

The interruption in the flow of the dye can also be effected using an apparatus of the structure shown in FIG. 7. Referring to FIG. 7, a piston 22 is moved reciprocatingly in the direction of A by an electromagnet 21. When the electromagnet is inoperative, the piston 22 is held in contact with a dye liquor discharge opening 26 using a spring 23, thereby to stop the discharge of the dye liquor. The reference numeral 24 represents an inlet for the dye, and 25, an outlet for the dye. An electric wire is shown at 27. The flow of the dye which enters the apparatus through the inlet 24 and the outlet 25 is interrupted by actuating the electromagnet 21 intermittently thereby reciprocating the piston 22 and closing and opening 26 intermittently.

By discharging two or more dyes from one dye applicator device alternately or randomly using such an apparatus, there can be obtained a yarn which is dyed continuously or intermittently in two or more colors along the length, as shown in FIG. 8. Referring to FIG. 8, a yarn 31 runs in contact, with dye applicator device 32 which is shown in detail as reference numeral 5 in FIG. 2. From a discharge aperture 33, dyes a, b and c of different colors are continuously or discontinuously discharged at varying intervals, and applied to the yarn 31 repeatedly in any order of a, b and c, or in a random sequence. The dyes which have been fed into dye intermitting devices 34, 34' and 34" through delivery pipes 35, 35' and 35" are intermitted here, and discharged from the discharge opening alternately or in a random sequence, and thus applied to the yarn 31. At this point, the dyed portions may be rendered continuous; or discontinuous, that is, undyed portions may be formed.

In conventional pad-dyeing the yarn to which the dye has been applied is steamed or subjected to a dry heat-treatment in the form of a package such as a cone or cheese, or in the form of a skein thereby to fix the dye to the fibers. However, the steaming method has the disadvantage that longer periods of steaming time are needed to achieve sufficient dyeing, and the efficiency is poor. The dry-heat-treatment has the advantage that the treatment can be completed within shorter periods of time but still poses the problem of the decomposition and sublimation of the dye because of the high-temperature treatment. Accordingly, in the present invention, the yarn is preheated to a temperature above the boiling point of a solvent in the dye prior to the application of the dye to the yarn, and then the dye, which can also be preheated if desired, is applied to the yarn, followed by a drying and a winding up of the yarn. This preheating of the yarn contributes to an activation of the molecular movement of the fibers, and the dye is applied to the yarn in the condition in which the internal structure of the fiber is relaxed. Thus, it is possible to dye the yarn instantaneously, and to dye at high speeds.

The heating temperature applied to the yarn prior to the application of the dye varies depending upon the type of the fiber but, usually, it is higher than the boiling point of the solvent employed in the dye and not higher than the point at which the physical and chemical properties of the yarn drastically change. The temperature of the dyes applied to the yarn is controlled within the range of 30.degree.C below the boiling point of the solvent of the dye up to its boiling point. For example, when water is used as a solvent for the dye, temperature of 70.degree. to 100.degree.C are suitable. At a temperature below 70.degree.C., long periods of time are needed for drying, and it is impossible to dye the yarn at high speed.

The yarn to which the dye has been applied is dried by passage through a dryer, and wound up to complete the dyeing operation. Usually, the dyeing operation is completed at this point, and post-treatments such as washing or soaping are unnecessary. A great advantage of this invention is that the dyeing is completed in this state. Where a darker color and a high fastness are desired, the wound up yarn may further be steam set.

The yarns that can be dyed by the method of this invention may be any yarns, such as spun yarns, continuous filament yarns or crimped yarns, composed of natural fibers such as cotton, wool or silk, synthetic fibers such as polyester, acrylics, polyamides and the artificial cellulose fibers such as viscose rayon, cellulose acetate or mixtures of these fibers.

The dye to be used in this invention can be chosen according to its suitability for the fibers to be dyed. If desired, a swelling agent for the fibers, a carrier or a solvent may be added to the dye in order to achieve the objects of this invention more effectively.

The dyeing according to the method of this invention can be carried out at a speed as high as 500 to 1,500 meters per minute without changing the tension of a running yarn, irrespective of whether the yarn has a non-uniform thickness or whether it contains knots.

The present invention will be illustrated in greater detail by reference to the following Examples.

EXAMPLE 1

A false-twisted nylon 6 yarn (70den/24fil/2ply) was passed at a speed of 600 m/min. through an apparatus shown in FIGS. 1 and 2 using a hot plate held at 200.degree.C as the heating means. A dye of the following formulation was passed through an applicator and discharged from an aperture having a diameter of 0.25 mm, and applied to the yarn, and after drying, the yarn was wound up on a cheese. The wound-up yarn was formed into a skein, and steamed for 5 minutes at 110.degree.C. A intermittently colored yarn having good quality was obtained.

______________________________________ Dye Formulation Amount (parts by weight) ______________________________________ CI Acid Red 219 50 Ethyl Alcohol 400 Benzyl Alcohol 40 Water 510 ______________________________________

EXAMPLE 2

A false-twisted nylon 6 yarn (1260den/80fil/3ply) was passed over through an apparatus of the type shown in FIG. 1 using a heater held at 200.degree.C and 0.1 cc each of the following three dyes A, B and C was intermittently discharged alternately 900 times per minute. Each of the dye was applied to the yarn which was running at a speed of 350 meters per minute. A tufted carpet having a uniform multi-colored pattern was produced using the resulting dyed yarn.

______________________________________ Dye Component Dye Formulation (parts by weight) ______________________________________ A B C CI Acid Yellow 114 5 8 16 CI Acid Black 64 1 2 6 Benzyl Alcohol 60 60 60 Ethyl Alcohol 200 200 200 Water 734 730 718 ______________________________________

EXAMPLE 3

A crimped nylon 6 yarn (840den/80fil/2ply) was passed at a speed of 500 m/min. through an apparatus of the type shown in FIG. 1 using a heated plate held at 200.degree.C, and a dye of the following formulation was applied to the running yarn at a discharge rate of 20 cc/min. During transit of the dye through a discharge pipe, air was introduced using an air pump into the dye 100 times per minute to form bubles, whereby the discharging of the dye was intermittingly interrupted. After drying, the dyed yarn was wound up on a cheese. An intermittently dyed yarn of good fastness was obtained.

______________________________________ Dye Formulation Amount (parts by weight) ______________________________________ CI Acid Black 58 30 Benzyl Alcohol 30 Water 940 ______________________________________

EXAMPLE 4

A polyester filament yarn (75den/24fil) was passed over a heater held at 210.degree.C at a speed of 700 m/min., and then the following dyes A, B and C were heated to 90.degree.C discharged each at a rate of 0.8 cc/min. from three dye applicator devices to apply them to the surface of the yarn. The yarn was then passed through a non-contact heater held at 150.degree.C., and wound up. The would-be cheese was formed into a skein, and steamed for 5 minutes at 140.degree.C. The surface of the yarn obtained was dyed three separate colors of very high fastness. Such a yarn has not been available heretofor.

______________________________________ Dye Formulation Amount (parts by weight) ______________________________________ Dye A: CI Disperse Yellow 42 10 Water 990 Dye B: CI Disperse Orange 13 20 Water 980 Dye C: CI Disperse Red 100 5 Water 995 ______________________________________

EXAMPLE 5

A spun yarn of wool (worsted count 40/3; 100% wool) was passed over a heated plate held at 160.degree.C at a speed of 700 m/min., and the following three dyes heated to 65.degree.C were discharged each at a rate of 16 cc/min. from three dye applicator devices, and applied to the surface of the yarn. The yarn was passed through a non-contact heater held at 140.degree.C to dry it, and wound up. The wound-up cheese was formed into a skein, and steamed for 10 minutes at 105.degree.C. A weft knitted fabric being of a sprinkled pattern of extreme clearness was produced using the resulting multi-colored yarn.

______________________________________ Dye Formulations Amount (parts by weight) ______________________________________ Dye A: CI Acid Yellow 141 6 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 534 Dye B: CI Acid Orange 56 5 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 535 Dye C: CI Acid Red 131 3 CI Acid Blue 138 2 Benzyl Alcohol 60 Ethyl Alcohol 400 Water 535 ______________________________________

EXAMPLE 6

A spun yarn of acrylic fiber (worsted count 20/2; 100% acrylic fiber) was passed over a heater held at 170.degree.C at a speed of 600 m/min., and 23 cc/min. each of the following three dyes A, B and C heated to 65.degree.C was discharged from each of three dye applicators shown in FIG. 2, and applied to the surface of the yarn. The yarn was dried by passing it through a non-contact heater at 130.degree.C., and woundup. The wound-up cheese was formed into a skein, and steamed for 10 minutes at 100.degree.C.

______________________________________ Dye Formulations Amount (parts by weight) ______________________________________ Dye A: CI Basic Yellow 11 6 Ethyl Alcohol 400 Water 594 Dye B: CI Basic Orange 33 12 Ethyl Alcohol 400 Water 588 Dye C: CI Basic Violet 26 15 Ethyl Alcohol 400 Water 585 ______________________________________

EXAMPLE 7

A spun yarn of cotton (cotton count 20/1; 100% cotton) was passed over a heater held at 170.degree.C at a speed of 600 m/min., and the following three dyes heated to 65.degree.C were discharged at a rate of 8 cc/min., from dye applicators of the type shown in FIG. 2 and applied to the surface of the yarn. The dyed yarn was passed through a non-contact heater held at 140.degree.C., dried, and wound-up.

______________________________________ Dye Formulation Amount (parts by weight) ______________________________________ Dye A: CI Reactive Orange 5 10 Soda Ash 10 Urea 100 Water 880 Dye B: CI Reactive Blue 17 25 Soda Ash 10 Urea 100 Water 865 Dye C: CI Reactive Black 6 20 Soda Ash 10 Urea 100 Water 870 ______________________________________

While the invention has been described in detail and in terms of preferred embodiments thereof it will be apparent that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims

We claim:

1. An apparatus for continuously dyeing a yarn comprising means for providing a running yarn, means for heating said running yarn, means for applying a dye to said running yarn, means for drying said dyed yarn and means for winding up said dyed yarn; said means for applying a dye comprising a plurality of dye applicators disposed in sequence along said running yarn and angularly offset from each other about said yarn, each of said applicators having a U-shaped groove, a dye discharging aperture disposed at the bottom of said groove and means for supplying a dye through said aperture.

2. An apparatus as set forth in claim 1 further comprising means for selectively controlling the supply of dye through the aperture of each applicator.