Yarn dyeing device

The present invention relates to a device for dyeing a moving yarn that comprises a liquid dye supply line, a first nozzle positioned above the yarn and configured to deposit dye on a first surface of the yarn, a second nozzle positioned above the yarn and configured to deposit dye on a second surface of the yarn corresponding to a surface opposite the first surface relative to the axis of the yarn, a synchronization mechanism for actuating the nozzles as a function of the movement of the yarn such that, between the first and the second nozzle, the yarn is able to pivot axially under the effect of the gravity of the dye deposited by the first nozzle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority benefits from Europe Patent Application No. 19315057.0 (“the '570 application”), filed on Jul. 4, 2019. The '570 application is hereby incorporated in its entirety by this reference.

FIELD OF THE INVENTION

The present invention relates to the field of the textile industry, and more particularly to the field of treating yarns by dyeing.

BACKGROUND

In the context of an industrial production of yarns for textile use, one essential operation that partly conditions its marketing relates to the step of coloring the yarn by dyeing it. The yarn is configured to be moved axially between two bearings such that the movement axis of the yarn crosses an ink jet intended to color it in a controlled manner. Currently, the deposition of the ink is carried out in the form of a continuous ink jet sprayed by a nozzle. The moving textile yarn passes through the ink jet. According to one exemplary embodiment, controlling the deposit of ink on the yarn involves a mechanism of periodic deflection of the ink jet with respect to the moving yarn when certain segments of the yarn are not intended to be dyed. The ink deflected so as not to dye the yarn is then recovered.

Although such a mechanism makes it possible to perform a controlled deposition of dye on the yarn with a movement speed of the yarn on the order of 600 meters per minute, it has the drawback of requiring that a large volume of dye be sprayed so that the yarn is colored over its entire section.

SUMMARY

The present invention aims to address these drawbacks by proposing a dyeing mechanism for a textile yarn that makes it possible to reduce the consumption of dye necessary for dyeing a yarn while allowing movement of the yarn at speeds of more than 500 meters per minute.

The invention therefore relates to a device for dyeing a yarn driven in movement, characterized in that the device comprises:at least one supply line for liquid dye,at least a first deposition nozzle positioned above the moving yarn and configured to deposit a liquid dye on a first surface of a portion of the length of the yarn,at least a second deposition nozzle positioned above the moving yarn and configured to deposit a liquid dye on a second surface of the same portion of the length of the yarn, the second surface corresponding to a surface arranged at the face opposite the first surface relative to the axis of the yarn,a mechanism for synchronizing the successive actuation of each of the deposition nozzles as a function of the movement of the yarn so that, between the first nozzle and the second nozzle, the portion of the length of the yarn is able to pivot axially under the effect of the gravity of the liquid dye deposited by the first nozzle.

The invention also relates to a method for dyeing a yarn using a device according to the invention, characterized in that the method comprises:a step for depositing a dye on a first surface of a portion of the length of the yarn by a first deposition nozzle,a step for axial movement of the colored portion of the length of yarn together with an axial pivoting of the colored portion of the length of yarn under the effect of the gravity of the deposited liquid dye,a step for depositing the same dye on a second surface of the same portion of the length of the yarn by the second deposition nozzle.

DETAILED DESCRIPTION

The invention relates to a device1for dyeing a yarn2driven in movement, characterized in that the device1comprises:at least one supply line3for liquid dye,at least a first deposition nozzle4positioned above the moving yarn2and configured to deposit a liquid dye on a first surface of a portion of the length of the yarn2,at least a second deposition nozzle5positioned above the moving yarn2and configured to deposit a liquid dye on a second surface of the same portion of the length of the yarn2, the second surface corresponding to a surface arranged at the face opposite the first surface relative to the axis of the yarn2,a mechanism6for synchronizing the successive actuation of each of the deposition nozzles4,5as a function of the movement of the yarn2so that, between the first nozzle4and the second nozzle5, the portion of the length of the yarn2is able to pivot axially under the effect of the gravity of the liquid dye deposited by the first nozzle4.

The expression “surface of a yarn portion” should be understood as referring to a part of the peripheral surface corresponding to a length of an arc on the order of 180° centered on the axis of the yarn2and along a length of the yarn2along the axis of the yarn2. Thus, during a movement along a substantially horizontal axis or along an axis forming an incline relative to the vertical, the yarn2comprises a yarn portion surface that is greater, that is to say oriented substantially upward, at which a deposition nozzle4,5is capable of depositing an amount of liquid dye.

The dyeing device according to the invention is thus configured to perform two successive dye deposits on each of the opposite faces of a same length portion of the yarn2by causing an axial pivoting of the yarn2. The successive positioning of a different face of the yarn2in front of a respective deposition nozzle4,5makes it possible to deposit dye on different surfaces of the same length portion of the yarn2. The inventive device is configured to allow the axial pivoting of the yarn2moving between the two deposition nozzles4,5. According to one preferred implementation of the inventive device, only a limited amount of dye is deposited by the first nozzle4on the first surface of the yarn2, so that the thickness of the yarn2is not impregnated with the dye and that, by gravity and under the imbalanced weight of the dye deposited on the first upper surface of the yarn2, the yarn2pivots axially by placing the first colored surface, initially upper, in the lower position and simultaneously pivots the second blank surface, initially lower, in the upper position.

According to a particular construction example of the device, the coloring of a length portion of the yarn2only requires depositing dye volumes strictly suited to the surfaces to be dyed. Indeed, while in the devices of the prior art, the coloring of a yarn length portion involves depositing dye at a first surface so that the dye passes through the thickness of the yarn to also color the surface of the yarn opposite the second surface, the inventive device allows the dye to be deposited at each opposite face of a length portion of the yarn2without requiring the presence of dye in the thickness of the yarn2. Also, in the context of a device1according to the invention, the volume of dye necessary to dye a length portion of the yarn2is less than that used in the context of a device of the prior art. This difference in required volume makes it possible to save dye by avoiding unnecessary coloring of the internal thickness of the yarn2.

According to another particular construction example, complementary to the previous particular example, the first nozzle4and the second nozzle5are supplied with liquid dye by a common supply line3. This arrangement makes it possible to deposit, by each of the nozzles4,5, the same color on each of the opposite faces of the thickness of the yarn2. Furthermore, this arrangement also makes it possible to obtain a uniform pressure at the liquid dye moving in the supply line3, so that the jet of dye obtained at each of the nozzles4,5is substantially identical.

According to another particular construction example, complementary to the various previous specific examples, the device1comprises a mechanism for managing the pressure of the liquid dye near at least one deposition nozzle4,5. This mechanism for managing the pressure of the liquid dye positioned on a part of the dye supply line3in particular allows a reduction in the pressure at the deposition nozzle4,5so that the quantity of dye sprayed by the deposition nozzle4,5is reduced in proportion. The pressure management mechanism thus makes it possible to manage the quantity of dye sprayed and to obtain an adjustable deposit of dye on the surface of the yarn2.

According to a specific feature of this other particular construction example, the pressure management mechanism comprises at least one dye ejection nozzle7. This dye ejection nozzle7, positioned on a part of the dye supply line3, for example near a deposition nozzle4,5, is controlled to reduce the pressure at the supply line by decreasing the quantity of dye present in the supply line3. The actuation of the opening of this ejection nozzle7is controlled by a control unit10. This control unit10can be connected to at least one sensor for the dye pressure inside the associated supply line3. This control unit10is preferably designed to manage the internal pressure of the associated line3automatically. According to a complementary preferred construction, the control unit10operates under the control of a programmed interface that predefines the quantity of dye to be deposited at least at a portion of the treated yarn2. Since the treated yarn2is in continuous motion, the quantity of dye to be deposited at a defined portion is then calibrated as a function of the pressure of the dye inside the associated line3. In fact, the higher the pressure inside the supply line3, the greater the quantity of dye sprayed at the deposition nozzle4,5. The pressure exerted by the dye inside the supply line3is generated by the continuous operation of a supply pump positioned upstream from the supply line3. Also, when the deposition4,5or ejection7nozzles are closed, the pressure inside the supply line increases. According to an alternative preferred construction feature, the dye supply flow from the pump is greater than the dye outlet flow at the set of deposition nozzles4,5associated with the supply line3, so that an operation of the deposition nozzles4,5with a permanent opening when no ejection nozzle7is open also allows an increase in the pressure inside the supply line3. The dye supply flow by the pump is also calibrated so that the opening of an ejection nozzle7performs a withdrawal of dye from the supply line3that is sufficient to reduce the pressure and/or increase this pressure generated by the continuous operation of the supply pump. According to a preferred construction, the adjustment of the pressure inside the supply line3involves several ejection nozzles7arranged at the same supply line3and controlled by the control unit10so that, by opening/closing only one of the ejection nozzles7or several ejection nozzles7simultaneously, the internal pressure of the supply duct3is able to be adjusted more finely, but also more quickly. Alternatively or additionally, the adjustment of the internal pressure of the supply line3involves one or more variable-flow ejection nozzles7. These variable-flow ejection nozzles7for example incorporate a diaphragm that adjusts the opening of the orifice of the ejection nozzles7as a function of the desired dye flow. Also, managing the pressure of the dye inside the associated line3via the control unit10allows an adjustment of the quantity of dye ejected at the deposition nozzle4,5and intended to be deposited on the moving yarn2. According to a specific embodiment of this feature, the control unit10operates in association with the synchronization mechanism6of the successive actuation of each of the deposition nozzles4,5of the device. According to an additional specific feature, this control unit10is integrated into the synchronization mechanism6of the actuation.

According to another particular construction example, complementary to the various previous specific examples, the device1comprises a mechanism for axial pivoting of the yarn2. According to an exemplary embodiment, this pivoting mechanism involves controlling the tension of the yarn moving between the two deposition nozzles4,5such that the traction produced on the yarn as part of its movement does not generate too great a tension on the yarn likely to prevent its axial pivoting. According to another exemplary embodiment, this pivoting mechanism comprises an interface for unbalancing the first colored surface of the yarn2, so that the yarn2pivots axially under the effect of the weight of the deposited dye. According to another exemplary embodiment, this pivoting mechanism comprises an interface for driving the axial rotation of the yarn2about its own axis. It should be noted that the pivoting mechanism integrated into the inventive device can be made by one or a combination of these exemplary embodiments of the pivoting mechanism.

According to another particular construction example, complementary to the various previous specific examples, the dyeing device1comprises:a supply line3,8for supplying liquid dye for each primary color and/or for the black color,a plurality of deposition nozzles4,5,4′,5′ aligned along the movement axis of the yarn2, so that each liquid dye supply line3,8supplies at least one deposition nozzle4,5,4′,5′.
One specific feature of this particular construction example makes it possible to carry out a combination of deposits of differing liquid dyes at opposite surfaces of a moving yarn2when the device1comprises two deposition nozzles4,5and each of these nozzles4,5is supplied with a respective color. Another specific feature of this particular construction example also allows the positioning of pairs of deposition nozzles4,5,4′,5′ supplied with a liquid dye of a respective primary color. Also, the presence of a pair of deposition nozzles4,5,4′,5′ for each primary color of liquid dye makes it possible to dye the moving yarn2in a wide range of colors owing to the combination of liquid dye deposits of one or more different primary colors. Each of the pairs of deposition nozzles4,5,4′,5′ is thus supplied by a respective supply line3,8. Each of the nozzles4,5,4′,5′ of a same pair is thus configured to color a different surface of the yarn at a same length portion. Furthermore, in this particular construction example, each of the liquid dye supply lines3,8is associated with a respective dye ejection nozzle7,7′ that participates in the mechanism for managing the pressure of the device.

According to another particular construction example, which is complementary to the various previous specific examples, at least one deposition nozzle4,5is associated with a mechanism9for interrupting the spraying of dye comprising at least one interface for deflecting the jet of dye sprayed toward a receiving tray. This mechanism9for interrupting the spraying of dye onto the moving yarn2makes it possible to maintain a constant flow of liquid dye sprayed by the deposition nozzle4,5while spreading the sprayed jet of dye relative to the moving yarn2. This mechanism9for interrupting the spraying by deflection of the jet thus authorizes an interruption in the deposition of liquid dye for a reduced time interval, on the order of 2 milliseconds. This mechanism thus allows precision in the deposition on the one hand, and in the absence of dye deposition on a yarn2moving at a speed on the order of 600 meters per minute on the other hand. Preferably, the mechanism9for interrupting the spraying of each of the deposition nozzles4,5,4′,5′ is associated with the mechanism6for synchronizing the actuation of the nozzles4,5,4′,5′. This synchronization mechanism6thus plays a role, in cooperation with the different nozzles4,5,4′,5′ that it actuates, in distributing one or more dyes along the length of the moving yarn2. This synchronization mechanism6preferably operates under the control of a programmed interface that predefines the desired coloring for at least a portion of the treated yarn2.

According to a preferred arrangement of the device1according to the invention, the liquid dye sprayed outside the supply line3by a deposition nozzle4,5,4′,5′ or by a dye ejection nozzle7,7′ and which is not deposited on a surface of the yarn2, is recovered at a dedicated interface to be reused, or even reinjected into the supply line3.

The invention also relates to a method for dyeing a yarn using a device1according to the invention, characterized in that the method comprises:a step for depositing a dye on a first surface of a portion of the length of the yarn2by a first deposition nozzle4,a step for axial movement of the colored portion of the length of yarn2together with an axial pivoting of the colored portion of the length of yarn2under the effect of the gravity of the deposited liquid dye,a step for depositing the same dye on a second surface of the same portion of the length of the yarn2by the second deposition nozzle5.

According to a particular embodiment feature of the inventive method, the method comprises at least one step of depositing a dye using a deposition nozzle4,5correlated with a step of opening a dye ejection nozzle7upstream from the deposition nozzle4,5so as to control the quantity of dye sprayed by the deposition nozzle4,5.

Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.