EP1203840B1 - Device for applying size to a yarn and method for adjusting the degree of sizing of a yarn - Google Patents

Abstract

To apply size to a yarn (17), and set the size coating, the yarn is treated with water and then the size is applied to the yarn from a bath (4) while some of the water carried by the yarn is dispersed into the size bath. The size concentration in the bath is at a given concentration balance. Size is transferred from a size supply bath (5) to the applicator bath during sizing, to maintain a constant concentration. To size yarns, the volume of size to be transferred from the supply bath to the applicator bath is determined by a monitor (7), calculated as the actual size coating value, which is set by the pressure on a roller assembly (9) where the actual and nominal size coating values are compared and controlled. In the initial stage, the yarn is passed through a roller assembly (8) to give it the required water content. An Independent claim is included for an assembly to size yarns, with a control system (6) at the sizing bath to maintain the size level. Preferred Features: The sizing assembly (1) has an additional monitor to measure the volume of size fed from the supply. The control system (6) has size level monitor (23), linked to a valve (24) to give a dosed delivery of size from the supply to top up the sizing bath. The system has an electronic control.

Description

The present invention relates to an application device from sizing to a yarn to produce an adjustable Degree of sizing on the yarn and a process for Setting the degree of sizing of a yarn.

The warp threads of a fabric are used during the weaving process subject to considerable mechanical stress. About warp thread breaks as much as possible during the weaving process Avoid, especially the warp threads are sized before weaving. The size treatment gives the thread smoothness, Compactness, strength and resistance to mechanical stress, especially against breakage. The sizing is a weaving tool; after weaving, if possible completely removed from the tissue. From cost and Environmental considerations should make the finishing job an optimal one Do not exceed the degree of arbitration. The optimal one The degree of sizing of a yarn is primarily dependent of the yarn type and of the subsequent weaving machine type.

Applying upstream of finishing has been advantageous of the yarn, with water, i.e. moistening the yarn proven in a separate step. The procedure and the Devices for this are described in DE-42 37 962 and in DE-4 234 279. The yarn is due to the moisture absorption on the finishing prepared. Due to the water content inside the thread remains the size essentially on the surface of the yarn, without significantly penetrating the inside of the yarn. this leads to Sizing agent savings compared to finishing the dry threads and after drying to an even thick sizing film.

The disadvantage of an upstream yarn moistening lies in the water input caused by the moistened yarn into the sizing container, resulting in a dilution of the ones there Sizing concentration leads. The finishing process itself on the other hand, a decrease in the absolute amount of size in the Sizing container, which is made by adding sizing from a Storage container must be balanced. These two processes, the water entry and compensation with sizing to relatively large fluctuations in the size concentration and thus to uneven degrees of arbitration from the Size container made of yarn. The degree of arbitration of the yarn must therefore in the prior art with expensive and complex measuring devices can be measured on the yarn. This Measurement is necessary to prevent it from being inadequate size yarn, especially warp threads, for warp thread breakage and thus leads to expensive loom downtimes.

The object of the present invention is to avoid the Disadvantages of the prior art. In particular, there is Task in a method and a device for adjustment a reproducible and uniform degree of sizing of a yarn for the entire duration of the To provide the finishing process. This procedure is supposed to enable complex measuring devices to determine the To dispense with the degree of conciliation.

Furthermore, a method for finishing and a device are intended for applying size, which are provided the sizing agent consumption to the technically required Minimum reduced.

These tasks are solved by an adjustment procedure the degree of sizing on a yarn in which the yarn water is applied in a first step and in a second step sizing from a sizing container is applied to the yarn, part of the with the thread transported water from the first step into the Size container is delivered, the size concentration in the wash tank of a predetermined equilibrium concentration corresponds to and the level of the size in the size agent container by regulating the addition of size a sizing reservoir during the sizing process is kept essentially constant

A similar process is known from EP-A-0 302 219, however used herein in connection with wet-on-wet treatment of a web.

In a preferred embodiment, the amount added Sizing from the sizing reservoir using a measuring arrangement detected. To compensate for the dilution effect the size concentration in the size reservoir is higher than the size concentration in the size container.

The equilibrium concentration is the size concentration (g dry mass / g H ₂ O) in the size tank, which is established after a certain time during the size process. After reaching the equilibrium concentration of the size in the size tank, the amount of water supplied from the moistened yarn and the amount of size (dry matter) from the size storage tank corresponds to that of the removed amounts of water and size (dry weight) from the size tank. The equilibrium concentration of the size in the size container is an experimentally determined variable. It depends on the difference between the size of the sizing agent between the storage tank and the size tank, the amount of water supplied per linear meter of yarn, the thickness of the yarn, the moisture content of the yarn during sizing, the type and composition of the yarn (e.g. natural fibers, synthetic fibers) of the chemical or mechanical Pretreatment of the yarn, the size of the size during the size, the composition of the size, the distance between the device for moistening and the application of size to the yarn, room temperature, etc. For example, in a given device at an initial concentration of 18%, the size in the Size container and with an 18% size concentration in the size storage container (g DM / g water) an equilibrium concentration of the size in the size container of 12% by weight after approx has an average water content of 55 to 60% by weight at squeezing pressures of 10/8 kN and was applied at a water temperature of 85 ° C. The equilibrium concentration is therefore a variable which can be determined individually and empirically for each yarn type.

The adjustment of the equilibrium concentration can be done as before mentioned depending on the given method and Machine parameters require a longer period of time to take.

In contrast, in the method according to the invention Size concentration in the size tank to match the yarn type adjusted and experimentally predetermined equilibrium concentration set from the beginning of the finishing process. During the finishing process, the level the size in the size tank by regulation essentially kept constant. The size concentration gives way so that it does not move away from the Equilibrium concentration. In ideal conditions, in particular with constant pinch pressures of the roller arrangements after finishing, there would be a constant equilibrium concentration in a constant uniform The degree of sizing of the yarn results.

Since the conditions are not always constant in practice, is actually realized in the method according to the invention Degree of sizing is advantageous over the measured added Finishing quantity calculated from the finishing hopper. This calculation is based on the fact that in Equilibrium state the supply of dry matter sizing agent is equal to the removal of dry matter sizing agent. The feed Dry matter is the product of the quantity supplied from the size Size storage container and the size concentration in the Reservoir. The removal of dry matter corresponds to the product from the liquor absorption [%] (kg size / kg yarn) and concentration the size in the size container and is synonymous with the degree of sizing (degree of sizing = Fleet absorption x concentration of the size in the size tank). Furthermore, the amount of size supplied corresponds to the balance the amount of size removed. So that the actual Degree of coating by measuring the quantity supplied Sizes from the size storage container with knowledge of other parameters, especially the concentration of the size in the sizing container and the running meter of yarn can be calculated. From the entry of a theoretical target value of Degree of sizing with that from the measurement of the size supply calculated actual value of the degree of arbitration results there is still the possibility of regulating the degree of conciliation in an advantageous embodiment of the invention. In an advantageous embodiment, this happens about the squeezing pressure of the roller arrangement after the finishing.

The size concentration results accordingly from the All of the loosened and / or suspended sizing agents in water. Not only the actual ones contribute to the solid content Sizing agents, such as chemically / or physically modified Natural substances (swelling starch, hydroxypropyl starch, galactomannans etc.) or synthetic polymers (polyvinyl alcohols) at, but also the auxiliaries and additives, such as waxes, Defoamer, oils, etc.

Part of the invention is also a device for loading from sizing to a yarn to produce an adjustable Degree of sizing on the yarn, the device a water tank, an arrangement for adjustment of the liquid content of the yarn and a size container comprises, wherein the water-loaded yarn the size container is feedable and the size container for receiving of water removable yarn Water is provided, the sizing container still a control arrangement for keeping the fill level constant Has size in the size container.

In a preferred embodiment, the device comprises additionally a measuring arrangement for measuring the quantity supplied Sizing from the sizing reservoir.

The amount of water carried with the yarn, i.e. the Water entry into the sizing tank is dependent or can are controlled via the squeezing pressure, which the yarn follows Subjecting the yarn to water. The Yarn can either pass through the water bath, followed by Roller arrangements for the desired moisture content of the yarn. In an alternative embodiment water is applied and squeezed off immediately on top of each other through the same roller arrangement.

The sized thread is also squeezed off by pairs of rollers. The squeezed amount of size must be so that the Calculation of the degree of arbitration is not falsified Quantity of size in the size container can be added. advantageously, this is done by a roller arrangement in the way that the squeezed size is in the size container flows back directly. Alternatively, the squeeze rollers however also arranged outside the size container be measured with the squeezed amount of size and taken into account when calculating the degree of arbitration must become. Applying size to the yarn can with the same two arrangements as the loading of the yarn with water. The yarn can hold the size container either run through or the sizing is done using roller onto the yarn.

The device further comprises a control arrangement for the Keeping the size level in the size container constant. This Control arrangement includes a level sensor and one with the Level sensor in operatively connected valve. In a preferred one Embodiment is a mechanical Control arrangement in the embodiment of a float. The Float is on one side above one in vertical Towards the movable arm with the container wall in a predetermined Height connected from the bottom of the container. On the other He is firmly on one side with an immovable arm Means for sealing attached with which the size feed of the sizing reservoir is sealable. Does that move Sizing level below the predetermined liquid level (Level), the means for sealing gives the size feed free. So much sizing has flowed in that the predetermined one Fluid level is reached again, so the float raised and the sealant closes the Simple supply.

In a further preferred embodiment, the liquid level with an electronic control system at constant Level maintained. The concept of regulation is in the present invention as defined in DIN Used in 19226. The controlled variable in the present case is that Level (i.e. the fill level of the wash in the wash tank), which is continuously recorded, compared with the setpoint and dependent the result of this comparison in the sense of an approximation is influenced to the setpoint. The resulting one Effectiveness takes place in a closed control loop instead of. The amount / volume of size supplied is in both Cases recorded using a measuring device.

Figure 1

Querschnitt durch eine erfindungsgemässe Vorrichtung in stark vereinfachter Darstellung.

The invention is explained in more detail with reference to drawings.

Figure 1

Cross section through a device according to the invention in a highly simplified representation.

According to FIG. 1, a device designated overall by 1 comprises to apply sizing to a yarn 17 one Water tank 2, a water reservoir 3, one Sizing container 4, a sizing reservoir 5, one control designated as a whole, a measuring arrangement 7, a roller arrangement in operative connection with the water tank 2 8, one with the sizing container 4 in operative connection standing roller arrangement 9, and feeders 10, 11.

The feed 10 can be switched over by means of a valve 12, so that the water from the storage water tank 3 either over the feed 10a can be fed to the water tank 2 or via the feed 10b to the size container 4. The Water tank 2 is up to a predetermined via the feed line 10a Water level filled. The amount of water / the volume of water is supplied via a measuring arrangement 13 and preferably regulated. In the embodiment shown, the Water level in the water tank 2 during the sizing process kept constant via an arrangement for level control 13. The arrangement for level control 13 comprises a level sensor 14, a valve 15 and preferably electronic Control arrangement 16. The water tank 2 is preferred with the exception of the recess for the roller assembly 8 and Feed arrangement 10a closed. However, this is not mandatory.

In the size storage container 5 there is size with e.g. an 18% concentration. The size container 4 is up to to a predetermined fill level with size of a predetermined Equilibrium concentration filled. The equilibrium concentration the size was determined in preliminary tests. For filling, water is taken from the water reservoir 3 via the feed line 10b together with size from the Sizing reservoir 5 via the feed line 11 to the sizing container 4 fed. A circulation pump is preferably used (not shown) during the filling and the duration of the Coating an optimal mixing of the water with the Schlicht. Preferably the water and sizing is close the sizing tank 4 fed to the suction port of the pump In any case, the equilibrium concentration is lower than the size concentration in the size storage container 5. About the measuring arrangements 13 and 7 can water from the water reservoir 3 and size from the size storage container 5 be dosed exactly. By entering the water content of the Yarns after passing through the roller assembly 8, the desired Degree of arbitration, the fleet admission and the Pinch pressure curve, determined by a connected to the control 6 Computer the size concentration to be applied in the Sizing container 4. The required sizing and amount of water calculated and automatically filled into the size container. The refill process is triggered by a corresponding command on the computer triggered.

The size container 4 is also in the present exemplary embodiment with the exception of recesses for the roller arrangement 9 and the feed 11 closed.

The roller arrangement 8 is in the present exemplary embodiment a ten ton squeeze. The yarn 17 is in the direction of the arrow passed through the roller assembly 8. The roller assembly 8 guides the yarn, wets it with water and squeezes it onto the predetermined moisture content. Applying with In the exemplary embodiment, water is realized in that a of the two rollers 18 of the roller assembly 8 into the water of the water tank 2 is immersed, causing a film of water forms on the roller surface of the roller 18. The water film provides a water wedge at the point in the roller arrangement 8, where the lower roller 18 meets the upper roller 19 20. The yarn is passed through the water wedge, charged with water there and immediately afterwards at Running through the nip to the desired moisture content brought. The moistened thread 17 is then passed through the roller assembly 9 and there with Simple applied. Also the application of the moistened Thread with size is carried out in the same way like loading the thread 17 with water. On by immersing the lower roller 21 in the size forming sizing film on the roller surface ensures a size wedge between the lower roller 21 and the upper roller 22 when the yarn enters for a film on the yarn 17, which after passing through the roller assembly 9 on a predetermined value is squeezed.

The control arrangement 6 consists of a level sensor 23, a Control valve 24 and an electronic control arrangement 25. Das moistened yarn 17 leads for the duration of the sizing on the one hand to the wash tank 4 water. Leads to the other the yarn 17 size through the sizing process from the Size container 4, whereby the fill level (actual value) below the predetermined level (setpoint) falls. The actual value is compared to the target value in the arrangement 25; is the deviation too large (± 5 mm from the setpoint), then open by of the valve 24 size from the size reservoir 5 fed to the size container 4 via the line 11 as long as until the setpoint matches the actual value. The amount of supplied sizing from the sizing reservoir 5 measured in the measuring arrangement 7.

The degree of arbitration can be calculated using one of the control arrangements 25 connected computers (not shown) occur.

In a preferred embodiment, by squeezing pressure control the roller arrangement (9) the degree of sizing Yarns (17) can still be adjusted.

The degree of sizing can be determined via the quantity of size supplied of the yarn, as already described, can be calculated.

In a preferred embodiment, a setpoint of the Degree of conciliation with that determined at certain time intervals Actual value of the degree of conciliation compared and in case of deviations the actual value via the tolerance value of the setpoint via a correction of the squeezing pressure on the roller arrangement (9) adjusted to the target value.

Claims (11)

1. Process for adjusting the degree of sizing of a yarn (17) by steps which include a first step of applying water to the yarn (17) and a second step of applying size from a size container (4) to the yarn (17), wherein a portion of the water transported with the yarn is discharged into the size container (4), characterized in that the size concentration in the size container (4) corresponds to a predetermined equilibrium concentration and in that the addition of size from a size stock reservoir container (5) is closed loop controlled to keep the level of the size in the size container (4) substantially constant during the course of the sizing operation.
2. Process according to Claim 1, characterized in that the amount of size added from the size stock reservoir container (5) is measured using a measuring instrument (7).
3. Process according to Claim 2, characterized in that the measured amount of size added from the size stock reservoir container (5) is used to calculate the current value of the degree of sizing.
4. Process according to any one of Claims 1 to 3, characterized in that the pressure exerted by a roll arrangement (9) is used to adjust and closed loop control the current value of the degree of sizing to the target value for the degree of sizing.
5. Process according to any one of Claims 1 to 4, characterized in that the yarn (17) in the first step is brought to a predetermined water content by means of a roll arrangement (8).
6. Apparatus (1) for applying size to a yarn (17) to produce an adjustable degree of sizing on the yarn (17), the apparatus (1) comprising a water container (2), an arrangement (8) for adjusting the liquid content of the yarn (17) and a size container (4), the water-treated yarn (17) being feedable to the size container (4) and the size container (4) being provided to receive water removable from the water-treated yarn (17), characterized in that the size container (4) comprises a closed loop control arrangement (6) for keeping the fill level of the size in the size container (4) constant.
7. Apparatus according to Claim 6, characterized in that the apparatus (1) further comprises a measuring arrangement (7) for measuring the amount of size fed from the size stock reservoir container (5).
8. Apparatus according to either of Claims 6 and 7, characterized in that the closed loop control arrangement (6) comprises a level sensor (23) and a valve (24) for metering the amount of size fed from the size stock reservoir container (5), said valve (24) being in operative communication with the level sensor (23).
9. Apparatus according to Claim 8, characterized in that the operative communication is an electronic controller.
10. Apparatus according to any one of Claims 6 to 9, characterized in that the arrangement (8) for adjusting the liquid content of the yarn (17) is a roll arrangement.
11. Apparatus according to any one of Claims 7 to 10, characterized in that the apparatus (1) comprises a roll arrangement (9) for adjusting the degree of sizing.

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