DE1935105A1 - Method and device for crimping yarn - Google Patents

Description

The invention relates to methods and processes directions for treating a running strand of yarn and "relates in particular to methods and devices for Achieving a uniform crimp in a thermoplastic Yarn as well as devices for maintaining uniform tension in a running yarn strand, while the skein of yarn is used for structuring serving treatment or the like.

It is already known a thermoplastic yarn thereby structure to give it the desired elasticity and to give a strong bulk by being the yarn for the purpose of crimping over a "sharp cutting edge" leads; measures are carried out at the same time, to continuously bend a heated strand of yarn over its entire length, so that latent tensions in the yarn or the yarn is crimped, so that an elastic yarn product is obtained. The crimped yarn can then be heated to this To develop tensions to a greater extent, so that

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a very fluffy textile yarn product is created.

A typical device for crimping yarn through Passing a strand of yarn over a cutting edge usually includes a heater to increase the temperature of the yarn to above the so-called glass transition point, a crimping element, e.g. a knife, a wire or a 'rod that is frictional with the heated one Yarn works together and the yarn sags to make it crimps, as well as yarn guiding and transport devices, by means of which a strand of yarn is continuously withdrawn from a supply spool and continuously longitudinally a predetermined path past the heater and around the crimper to a collector to be led.

In order to achieve even crimping of the To facilitate yarn skein, it is useful to keep the running yarn skein in the area of contact between the Skein of yarn and the crimping element under an even Zugspinung to hold, so that the frictional contact between the yarn strand and the crimping element to generate results in more uniform latent tensions in the yarn. Since thermoplastic yarns contract when heated, it is also expedient to keep the yarn strand under a relatively small amount during its heating and before it comes into contact with the crimping element. To keep tension, so that he can contract unhindered .. They are various devices have been proposed to accomplish these objectives. In the U.S. Patent 3 028 654- is a curling device with a Cutting edge or edge described in the case of the drivable Rollers or lollipops serve to inevitably make the skein of yarn at a first linear speed to the heating zone. and the heated yarn from the tendon

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the curling element inevitably peeled off at a slower speed than the average To compensate for the contraction of the yarn as it is heated. Such a necessarily working device however, it is not suitable for feeding and withdrawing the yarn, to compensate for the irregular contraction of the yarn during its heating due to uneven pressures and stresses to which the skein of yarn is exposed due to its different position on the supply spool. Because of this irregular contraction of the strand of yarn while it is being heated the strand of yarn exposed to different tensions on the crimping element, so that the evenness is reduced with which tensions are generated in the yarn by the crimping element in order to produce a crimp.

In U.S. Patent No. 5 01? 684 is a. Described crimping device working with a cutting edge, in which the tension in the running yarn strand on the exit side of a knife-like crimping element is regulated in that a tension sensing device is provided on the outlet side of the knife, which serves to slow down the rotational movement of two with a variable to cause the yarn strand cooperating wheat or rolls, which are arranged on the singang side of the heating zone upstream of the crimping blade, so that the frictional resistance acting on the yarn can be varied in order to adjust the tension of the yarn running over the blade. However, this device only maintains an even tension in the yarn strand on the run-off side of the blade if the tension applied to the yarn by the brakable pods remains greater than any brief increase in tension that occurs in the running yarn strand in front of the rollers

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BATH ORIGINAL

193510

can occur. Any sudden change in voltage ^ art that the voltage exceeds the force applied by the rollers voltage, longitudinally of the yarn strand acts beyond the rollers from die.noch an enlargement of the deviations cause, as well as ^in: the crimping zone, so \ that results in an irregular crimp of the yarn. Ha is the amplitude of the tension acting on a strand of yarn while the strand of yarn is being pulled from a

effective

Gate body, e.g. a coil, / significantly changed, depending on the respective position of the running yarn strand on the outside of the bobbin as well as the way in which the thread is withdrawn from the bobbin, must be the tension in the yarn heating zone and the curling zone, i.e. in the area of the curling organ, must always be higher than the highest tension applied to the Garnzuführuhgsstelle can occur if an even tension is to be maintained »This requires of course the maintenance of a relatively high tension in the strand of yarn within the heating zone it is desirable to operate at low tension in order for the skein to relax in the desired manner and can move in together

The aim of the invention is now to create Methods and apparatus for uniformly crimping a continuous strand of thermoplastic yarn which the above-described disadvantages of the known methods and devices are avoided. Further sees the invention methods and devices for uniform Before crimping a running thermoplastic yarn strand, in which it is possible to get the yarn ' heat while it is at a relatively low voltage. is set so that it can contract freely and that allow the yarn to pucker after it has been heated, while giving it a uniform

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Voltage is exposed to ensure that in the Yarn even tensions are generated, so that too a uniform crimp is achieved. In the end the invention provides a device which makes it possible in a running strand of yarn a uniform To maintain tension while the yarn is being textured or subjected to other treatment

The invention and advantageous details of the invention are explained in more detail below with reference to the mathematical drawings of an embodiment.

Pig. 1 is a schematic perspective illustration of a yarn structuring device for uniform Crimping a running thermoplastic yarn strand according to the invention.

2 is one drawn to a larger scale perspective "representation of the clamping device, by means of which in the running yarn strand on the outlet side of the crimping element of the structuring device Fig. 1 a uniform tension is maintained.

The illustrated yarn structuring device according to the invention generally comprises a first yarn transport device IO and one located at a distance therefrom. arranged second yarn transport device12 'for compulsory ■ _. . * ■: continuous movement of a strand of yarn along a predetermined path, furthermore a heating device arranged in the path of the yarn between the two transport devices. 14 for heating the yarn fed to it, a crimping device 16 arranged in the path of the yarn between the heating device .14 and the second yarn transport device 12, which works in a frictional manner with the heated running yarn strand so that the yarn strand is continuously bent over its entire length

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and latent tensions arise in the strand of yarn, as well as one in the path of the yarn between the crimper 16 and the second transport device 12 arranged device'20 for sensing the tension in the between the curling device and the second Transport device extending part of the strand of yarn and to regulate the speed at which the yarn "is moved by the second transport device / in such a way that in the run off from the crimping device Maintain even tension on the skein of yarn will. ■ "- - ':

The first yarn transport device 10 comprises two rollers 22 and 23 cooperating with the yarn strand, which are inevitably driven in order to pull a yarn strand 21 off a yarn supply, for example a yarn bobbin 24, and to pull the strand continuously, inevitably and under a relatively low tension of the heating device 14 - To be supplied, which, according to FIG. 1, comprises an electrically heated plate 26, by means of which the temperature of the yarn. Strand is increased to a value that lies between the first and the second transition point. The heated yarn 21 running off the plate 26 is brought into frictional contact with a crimping device 16 which, as shown in FIG. 1, comprises a blade 28 with a sharp edge, and is drawn by the second yarn transport device 12 under a higher tension over the sharp edge of the blade so that the strand of yarn is continuously bent over its entire length in order to generate latent tensions in it. The crimped strand is then continuously collected with the aid of a device that takes up the yarn under low tension, ie it is wound up with the aid of a ring spindle 30, for example. -

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The yarn transport device shown on a larger scale in FIG. 2 in connection with the sensing device 20 for maintaining a uniform tension in the yarn strand on the sequence side of the crimping blade comprises two conical transport rollers 32 and 34. According to FIG. 1, the conical rollers 32, 34 and the cylindrical rollers 22j 23 as well as the winding spindle 30 are connected to the drive shaft 41 of an electric motor 42 by drive belts 36, 38, 40 and pulleys used a different diameter. According to FIG. 2, the right-hand conical roller 32 is positively driven by the belt 36, while the left-hand conical roller 34 is mounted on an axle 35 "and is driven by its frictional contact with the driven roller 32". The conical rollers can from the consist of the most varied of materials; however, one must choose a material which guarantees an unavoidable transport of the yarn strand 21 along the intended path The circumferential surface of the roller 34 consists of a soft material, for example rubber, in order to ensure that the yarn strand is inevitably transported through the conical rollers _e

The sensing device 20 comprises a rotatably mounted guide arm 50, one end of which in the path of the Yarn on the input side of the conical rollers 32 and 34 is arranged, and the tension in which he pulls— the skein of yarn is felt, and the transport is speedy. speed of the strand by regulating the position of the Path of the yarn opposite the circumferential surfaces of the conical Rolling varied. The guide arm 50 is between his

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Ends by, supported by an axis 52 and at one end, provided with a thread guide eye 53 which is arranged so that it the thread skein 21 in tangential direction to that of the viewer of Pig. 2 applied side of the conical roller 34- leads so that the strand of yarn wraps around the roller 34 within a considerable angular range before it enters the gap between the two conical rollers; occurs, so that an inevitable Iran port of the strand is ensured by the rollers' shown in FIG. 2 causes a change of position of the yarn strand along the axes of the conical rollers as indicated by the broken lines P ¹ and P ",, a Increase or decrease the speed at which the strand of yarn moves along the intended path. ',

At the other end of the guide arm 50 is means a spring 54- a weight 56 attached, through which on a constant torque is applied to the arm 50 according to FIG. 2 in order to preload the arm clockwise » The spring 54 forms a resilient link through which the mass of weight 56 relative to the sensing device is isolated, so that sudden shifts in weight during pivoting movements of the arm 50 to shift the haul of yarn to be avoided · It should be noted that one the weight for biasing the guide arm easily by another device for applying a essentially constant torque on the Ann. . ' could set, e.g. by a constant torque generating motor or some other elastic member with a relatively small spring constant that is within a relatively small deformation area takes effect TJm to prevent excessive deflections of the guide arm 50, when a movement of the arm 50 to correct the trans- ' Port speed of the yarn has been initiated, one can provide a damping device, e.g.

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pneumatic cushioning cup that works together with "one piston 58 »whose piston is connected to the guide arm and serves to control the speed of movement of the To regulate the guide arm ,, ·

When operating the device according to FIG. 1, the Strand 21 made of thermoplastic yarn is drawn off in the axial direction from the supply reel 24 and passed through the transport rollers 22 and 25 inevitably fed to the heating plate 26, in the area of which the yarn under a relative low tension, so that it is during its Heating can contract unhindered. Due to the inevitable supply of the strand of yarn to the heating zone Help the driven transport rollers 22 and $ 2 to the Irregular tension changes, in particular in the running yarn strand in front of these rollers, are in the heating zone occur when pulling the strand of yarn from the supply spool, kept away from the heating zone, so that sudden undesired increases in the tension of the yarn within the heating zone and on the crimping blade 28 are avoided » The heated yarn is after passing the heating plate 26 driven by the conical rollers 32 and 34 to the cutting edge of the crimping blade 28 is drawn around to continuously taper the strand of yarn over its entire length bend and generate latent stresses in it. The part of the yarn strand running off the crimping blade 28 moves upwards, then through the miter eye 53 of the pivotable arm 50 and finally between the conical rollers 32 and 34, when the tension of the strand of yarn is on the downstream side of the crimping blade temporarily increased, the guide arm 50 is counter to counterclockwise the biasing force of weight 56 " pivoted so that the path of the yarn auf'den. Circumferential surfaces of the conical rollers in the direction of the thinner ends of the rollers is shifted, whereby the

Speed of pulling the yarn from the crimping blade reduced and the tension of the yarn is reduced to the "preselected target value. Correspondingly effected a temporary reduction in the tension of the strand of yarn on the downstream side of the crimping blade, that the guide arm 50 is pivoted clockwise to the path of the yarn towards the thicker ends of the conical rollers so that the yarn is drawn off the crimping blade at a higher speed and its voltage is kept at the setpoint o

To the sensitivity of the guide arm 50 for this To bring small changes in the yarn tension to an optimal value, it is useful if the web of the strand of yarn between the blade 28 and the guide eye 53 substantially at right angles to the longitudinal axis of the arm and to its axis of rotation, while extending from the guide eye 53 to the circumferential surface of the conical Roller 34 - part of the strand of yarn preferably running is held generally parallel to the bearing axis of the guide arm 50, so that the skein of yarn in an optimal manner over the circumferential surfaces of the transport rollers 32 and 34-passed will.

Although it was mentioned above that in the crimping device according to the invention, a heating plate for Heating * and a blade is used to pucker the running yarn, but it should be noted that this is done Other devices could also be provided for purposes within the scope of the invention. For example, the heating device designed as a heatable shell or as a heatable tube while the device, which comes into frictional contact with the running yarn, is supported by a rod, a wire, an air stream or a part of the running yarn strand itself can be formed »Furthermore, the

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Tension of the yarn on the downstream side of the crimping blade can be determined with the help of other sensors, e.g. measuring transducers, the mechanical signal proportional to the yarn tension into an electrical pneumatic or hydraulic Convert the signal and control a variable-speed drive motor for the transport trolleys.

The previously described inventive combination of a yarn transport device with a tension in the yarn strand approaching this device, which senses the transport speed of the yarn strand changed in each case so that the tension in the incoming yarn strand remains the same, can also be done with others Yarn treatment devices than the crimping device described be applied. It therefore has an independent inventive significance.

From the above description it can be seen that the invention enables in the strand of yarn on the downstream side the crimping blade to constantly maintain an even tension, so that in the strand of yarn in substantially uniform tensions can be generated and a uniformly crimped yarn is obtained. Because an additional Apparatus is provided by means of which the yarn is inevitably fed to the heating zone in such a way that the yarn is in the heating zone When exposed to relatively low tension, the yarn is free to contract, thereby creating a uniform crimp is further facilitated.

Claims;

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Claims (7)

PATENIDANSPEU CH E A method for evenly crimping a tepid thermoplastic yarn strand, characterized in that the yarn strand is continuously withdrawn from a yarn supply, that the yarn strand is inevitably fed to a heating zone in order to protect the yarn strand during its withdrawal from the To isolate tensions acting on the yarn supply and to keep the yarn strand in the heating zone under a relatively low tension, in order to make it easier for the yarn strand to contract while it is being heated, that the yarn strand in the heating zone is heated to a temperature between its first and its second transition point , and that the heated skein of yarn is drawn around a friction-generating surface to continuously bend it over its entire length and to generate latent stresses in it, the speed of pulling the skein of yarn from the friction-generating surface is controlled so that in the Cooking running down from this area an even tension is maintained. " 2. The method according to claim 1, characterized in that g e k e η η -, records that the speed of "peeling." of the skein of the friction generating surface thereby it is regulated that the voltage in that of .dl · et? Felt part of the strand of yarn running off * ia $! and that the speed deg removing the # araet * | ii ^ ir in .. 903884/1646 ■ - ^: M \ ^ Depending on changes in the tension of the strand of yarn is varied. 3. Device for carrying out the method according to claim or 2, characterized by a first yarn transport device (22, 23) and a second yarn transport device (32, 34) arranged at a distance therefrom for the positive movement of a yarn strand (21) along a predetermined path , a heating device (14) arranged in the path of the yarn strand between the first and the second yarn transport device for heating the yarn strand fed to it by the first yarn transport device, a device (28) arranged between the heating device and the second yarn transport device which frictionally touches the heated yarn strand, in order to continuously bend it and to generate latent tensions in it, as well as a device (20) arranged between the device frictionally engaging the yarn strand and the second yarn transport device for sensing the tension of the part of the yarn strand extending between these devices and towards m controlling the transport speed at which the yarn strand is moved through the second Garntransportvorrichtung such that a uniform tension is maintained in the running of the frictionally engaging the skein device part of the yarn strand, in order to facilitate the production of uniform tension in the running yarn strand. 4. Apparatus according to claim 3, characterized in that the second yarn transport device comprises two drivable conical rollers (32,34) which cooperate with the yarn strand along part of their peripheral surfaces in order to pull the yarn strand over the edge of the blade, and that the Device (20) for sensing and regulating the tension of the strand of yarn comprises a yarn guide device (50, 53) arranged near the entry side of the conical transport rollers, the position of which depends on changes in the tension in the part extending from the edge of the blade to the conical transport rollers 9098 84/1646 -3.- J9351Q5 of the strand of yarn changes, um, the position of the path of the strand of yarn on the circumferential surfaces of the conical transport rollers to vary so that the transport speed of the strand of yarn is increased or decreased. 5. Apparatus according to claim 3, characterized in that the device (20) for sensing and Regulating the tension of the strand of yarn (21) a lever (50) rotatably mounted between its ends with a lever on one of its ends Ends arranged yarn guide (53) and a device (54,56) comprises the lever in one direction of rotation pretensioned to support the strand of yarn and feed it to the gap between the conical transport rollers (32,34), Each change in tension in the running strand of yarn causes the lever to rotate, to vary the position of the path of the strand of yarn on the circumferential surfaces of the conical transport rollers and the speed, with which the strand of yarn is transported, to increase or decrease accordingly. 6. Apparatus according to claim 5, characterized in that g e k e η η, that the lever (50) prestressing device in one direction of rotation is a weight (56) which over a spring (54) hangs on the lever. 7. Apparatus according to claim 5 or 6, characterized in that g e k e η η shows that the lever (50) is engaged by a device (58) which dampens its movements. 90938A / 1646