The winding process is the transfer of the yarn from the bobbin or bobbin it is wound to another bobbin. This process is also called bobbin transfer. After the threads are produced, they are wound on cops or bobbins as in the open-end spinning system. After this stage, there are two ways to yarn. or it will be handled as a raw material in the enterprise and shipped to the weaving or knitting enterprise. COILINGoperation is done.
Because there is a small amount of yarn (60 gr on average) on the cops shipped from Ring spinning machines. In winding machines, these cops are combined and made into coils weighing 1,8 kg - 2,0 kg. Here, the thin and thick places on the yarn, double yarn and fish errors are cut and removed by the cleaner. If knitwear yarn is worked in the bobbin machine, paraffin is given to the yarn. The thick places on the yarn create a faulty surface in knitted or woven fabrics, especially if the beard or double yarn type errors reach the needles of the knitting machines, they both break the tissue and break the needle. These errors, which directly affect the costs, must be cleared from the yarn during the winding process.
DUTIES OF THE COIL MACHINE
Combining the yarns wound as cops on a 1-ring spinning machine, to turn them into bobbins weighing 1,8 kg - 2,0 kg.
2-To eliminate yarn irregularities (neps, fish, knots, thickness and fineness, etc.) that may cause weaving-knitting errors and breaks in machines.
3-For yarns that will be dyed as a bobbin, winding them on perforated dye bobbins that will allow the dye to spread easily on the thread.
Since the twist is given in a short distance in the 4-ring spinning machine, the twist distribution is not uniform. Smoothing the twist distribution when passing the yarn from the cop to the bobbin.
ERRORS DURING YARN BOBBINING
1-thin-thick place in the thread:
Thick places in the yarn are less twisted places. Thick places reduce the strength of the yarn and cause breaks in weaving. Thin places are the places where the fiber is low in the yarn. It causes breaks and fabric defects.
2- Knot in thread:
The knots on the yarn can be of different sizes. Warp threads with knots do not pass through the lamellas, they break. In knitting, it causes needle breakage.
Insertion errors occur because the end, which is taken from the unspun part during breakage in the spinning machine, is placed under the yarn delivery cylinder together with the other end and delivered.
These are the errors that occur when the fly in the spinning mill is wound on the yarn.
5-Vegetable and animal wastes:
Vegetable and animal wastes are residues that can reach from bale to yarn. It causes errors during weaving.
6-Double thread error:
It is formed by twisting and winding two yarns coming out of the last drafting cylinder in the spinning machine on a spindle. It creates particularly significant surface defects.
MAIN ELEMENTS IN CLASSIC AND MODERN COIL MACHINES
It is the element that ensures that the yarn is conveyed on the bobbin bobbin crosswise or straight during winding. Especially found on cross-wound bobbin machines.
It is the element that provides the winding of the yarn at a constant and certain tension and also helps to clean it. There are varieties with spring cylinders and discs.
It provides the process of removing the thin, thick, knotted, twisting faults from the yarn by cutting with the help of a knife during the spinning of the yarn from the cop to the bobbin.
4- Thread probes:
The task of the yarn detectors is to make the bobbin stop at the moment of breakage. Yarn checkers are located after yarn clearers.
In the winding machine, all the spindles on which the bobbins are seated must be in the same position and when viewed from above, the spindle must be visually vertical. The position difference between the spindles directly affects the yarn tension. When the yarn path is examined from the bottom up, the yarn untied from the cop seated on a spindle at the bottom passes through the balloon breaker (anti-balloon device).
Here, the yarn balloon is narrowed. In the pre-cleaner, especially the trash remaining on the yarn and as much neps and fly as possible are cleaned. After the precleaner, the thread passes through the tension hook. The task of the tension hook is to push the end of the yarn forward and ensure that it is wound at a certain tension. The upper suction arm provides to find the end of the yarn wound on the bobbin.
The thread passing through the tension hook passes through the sensor. Its task is to control the line of the yarn and ensure the winding of the yarn. The forked probe (tension) checks if the yarn is present. If the thread is not felt by the forked probe (i.e. no thread), the lower bobbin is replaced. Then the thread passes through the brake assembly (sensor).
The aim is to provide controlled winding of the yarn and to break the weak places on the yarn with tension.
If knitwear yarn is being worked, the yarn is paraffinized. The suction nozzle (upper suction arm), also called “deveboynu”, absorbs this yarn when the yarn breaks. It is cleaned from yarn faults in the yarn clearing device. In the thread knotting device, the two ends of the broken thread are added to each other. The two ends of the yarn are not knotted and the yarn ends are welded with the help of compressed air (with the help of the Splicer). Finally, the yarn is wound on the bobbin, which is rotated by the grooved drum as a result of rubbing.
Balloon breaking device:
The balloon breaker shrinks the balloon that occurs while the yarn is unwound from the cop. In other words, it prevents further stretching of the yarn and allows working with high winding speeds. The cop, in its position, centers the anti-balloon assembly and the brake assembly inlet. By means of the rotated bobbin, the yarn is started to be unwound from the cop.
Thus, a tension begins to appear in the moving yarn. Continuation of bobbin winding will require the emptying of the bobbin, and when the bottom of the bobbin is reached, the tension in the yarn will reach its maximum value. The reason for this is that the small balloon in the filled cop grows in parallel with the emptying of the cop. As the winding speed increases, the tension generally increases. Another task of the anti-balloon device is to ensure that the yarn is unwound from the cop without spiraling. In this way, it is possible to work with high bobbin speeds without over-stretching the thread, and the density in winding the thread on the bobbin does not change. This is very important for paint coils.
The pre-cleaner (sensor) is under the yarn brake and prevents the breaks in the bow-shaped yarn that may come from the cop due to twisting from entering the brake area. The yarn is guided through a slit formed by the edge of the guide plate and the movable clamp arm. The narrowest adjustment distance of this slit is 0.5-0.7 mm. Slit spacing 0,5-2,0 or 2,6 mm by means of adjusting knob with scale and adjusting lever-It can be adjusted steplessly up to
Thread brake assembly :
The task of this device is to give a homogeneous tension to the yarn. Thus, the weak places on the yarn will be broken with the effect of this tension and the bobbin will be wound with a certain stiffness. The most suitable braking force (ie tension) that can be applied to the yarn is approximately 8 -12% of the breaking strength of the yarn.-should be around . If the tension is increased, the elasticity on the yarn is lost and this causes dense yarn breaks especially in weaving. If the tension is kept low, the weak places on the yarn will not break.
Yarn suction nozzle and closing flap:
If the yarn being wound on the winding machine breaks, the yarn suction nozzle sucks the lower yarn between the guide plate and the cop. The closing flap closes the mouth of the yarn suction nozzle. At the time of yarn breakage, the yarn suction nozzle absorbs the lower yarn and keeps it tightly sucked through the continuous suction air in the duct. Closing flap, by means of magnet; It closes the mouth of the thread suction nozzle during the binding of the lower and upper threads after the thread breakage and during the replacement of the full bobbin.
Electronic yarn clearer:
The electronic yarn clearer, located after the yarn brake, removes errors such as thick places, thin places and double yarn on the yarn. In order to achieve this, the electronic cleaner controls the yarn passing through it and sends it to the computer of the bobbin spindle; It sends signals such as static yarn signal, dynamic yarn signal, thick ground signal, thin ground signal and double yarn signal. Electronic yarn clearer works according to optical system and capacitive system. In the optical system, the diameter of the yarn is measured by light, and in the capacitive system, the mass of the yarn is measured with capacitors.
Settings that can be made on the electronic yarn clearer
2-Thread number: The actual yarn count determined in the laboratory is set on the scale.
3- Thread diameter adjustment:The thickness of the yarn diameter is specified in %.
4-Speed adjustment: The value of the winding speed in the winding machine is set on the scale.
5-Error size adjustment : It is the cutting of the faults above the acceptable fault length of the knitting and weaving thread on the fabric.
6-Thread knotting device :
The yarn knotting device consists of a splicer system in which the yarn ends are not knotted but welded to each other and there is no end in the joint and even the joining place cannot be noticed. Splicer; It is the knot-free joining of the yarn ends with the help of compressed air. With an air splicer, the twisting of the yarn ends is first prepared by opening it with air, then it is mixed together and twisted together with air tubulance. The strength of this joint of the yarn is close to the normal yarn strength.
7- Thread delivery drum:
The yarn controlled by the yarn probe is wound on the bobbin which is rotated by the drum bar. Since the bobbin sits on the grooved drum, with the rotation of the grooved drum, it rotates the bobbin by touching it from the periphery, while the yarn that enters the channel on it moves left and right. The benefit of driving a bobbin from the periphery is that the winding speed does not change regardless of the diameter increase. Grooved drum according to the usage area of the coil
The course of the grooves in it is 1,5 - 2,5 ways. In other words, it means that the yarn is wrapped around the bobbin 1,5 - 2,0 or 2,5 times from one edge of the bobbin to the other. Since the drum and the coil rotate together, the inclination angle of the channels on the drum becomes equal to the coil winding angle. The slope of the channels can be symmetrical or asymmetrical.
8-Belt breaking device :
The bobbin is rotated around the circumference by the grooved drum during winding. As the yarn is wound, as the diameter of the bobbin increases, the number of revolutions of the bobbin decreases, while the number of revolutions of the grooved drum will remain the same, so the revolution rate between the bobbin and the drum changes. In cases where the revolution ratios coincide with non-fractional numbers, the windings made one after the other very often come together and form a belt. In case of winding the dye bobbin, as these belts cause abrasive yarn dyeing, several winding layers may jump out from each other during unwinding. The task of the belt breaking device is to prevent the yarn layers from winding up on each other by shifting the grooved drum a little compared to the bobbin during winding.
9-Stop devices on full coil :
The fullness of the coils being wound in each winding head is determined by the metering system and the diameter measuring system, and the filled coil is stopped and replaced.
a-Length measurement system:
This system serves to obtain the desired length of coil. During the winding process, the bobbin spindle computer measures the length of the yarn wound on the bobbin. When the desired length of yarn is wound on the bobbin, the bobbin spindle computer stops the drum and the bobbin is changed.
b-Diameter measuring system:
When the bobbin reaches the desired diameter, it is stopped by the diameter stop device. The spindle computer continuously detects the bobbin diameter from the speed ratio between the yarn guide drum and the bobbin. when the desired diameter is reached the spindle computer will stop the bobbin and the full bobbin will change.
PURPOSE OF INVISIBLE CONTROL OF BOBBIN YARN
Unevenness on the yarn; occurs in weaving, knitting, dyeing, finishing and ready-made clothing. These errors cannot be corrected in subsequent processing steps. For these reasons, it is absolutely necessary to check the unevenness of the bobbin yarn. The purpose of the evenness control of the bobbin yarn is to accurately measure the change in mass and weight per unit length. way is observed. In unevenness, the diagram is used to identify the characteristics of significant deviations. In the unevenness device, the test of the packaged yarn is made and this test is evaluated. The following criteria are important in the evaluation.
% U unevenness value (thin place, thick place, neps)
% CV change coefficient
According to the type, quality and type of yarn produced, the quality of the yarn is determined by TSE, ASTM, ISO and unevenness statistical values.
% U Measures affecting mass change
1-% - 50% thin place
2-+50% thick place
3-% + 200 neps (ring)
4-% + 280 neps (open end)
Coiled yarn is not a perfect yarn. The general characteristics of the blend, the machine, equipment and air conditioning conditions at the production stage cause faults in the yarn. Despite all care and control, yarn faults such as thin places, double yarns, thick places, neps, hairiness and fish occur on the yarn. Sample bobbins are taken from the winding machine to check for unevenness. It is brought to the laboratory. It is kept for 20 hours under standard atmospheric conditions (Temperature, 2± 65 oC, humidity 2± 24%). Coils that adapt to laboratory conditions are checked.
It is to increase the resistance of the yarn against friction. The resistance of the yarn against friction is extremely important in terms of the processes it will see later. Especially knitting and sewing threads are threads that are exposed to high friction. It is possible that excessive friction will occur in the yarn due to the characteristics of the machines during the processes, and as a result, the strength will decrease. This type of yarn must have a very high resistance to friction. Friction; It prepares the ground for negativities such as deterioration in the yarn, abrasion, loss of strength. With paraffinization, these problems are tried to be reduced. The process of covering the surface of the yarn with small paraffin particles and giving the surface lubricity is called paraffinization. The yarn obtained as a result of this process is called paraffin yarn.
The waxing process is done in two ways:
1-Solid waxing: It is generally used in yarns whose raw material is produced from natural fibers.
2-Liquid waxing: It is mostly applied in filament yarns.
First of all, the paraffin should penetrate the surface of the yarn well. 0,5 g to 1,5 g paraffin is given to one kilogram of yarn. In other words, if the waxing rate of the yarn is between 0,05 and 0,15 %, it means that the waxing process has been done correctly. The variation of the friction coefficient in the yarn differs according to the amount of paraffin. The amount of paraffin in the yarn should neither be too much nor too little. Being more or less than necessary affects the coefficient of friction. The following conditions should be considered when choosing paraffin:
1-Type of yarn (raw material, place of use, etc.) 2- Ambient temperature (season, environmental conditions, etc.) 3-How to get wax of each yarn (solid or liquid)
Paraffin selection and waxing is done according to the above conditions. But the most important thing is the change in the friction coefficient in the waxed yarn. The amount of paraffin in the yarns was determined by experiments. As a result of the experience gained, the amount of wax removal in all yarns has been determined as 0,5-1,5 grams per kilogram of yarn.
Acceptable humidity value of cotton fiber is 65 at 2% _+20 relative humidity and 2-+ 8.5 °C, which are accepted as standard conditions for production stages. Commercial humidity is 14% in wool yarn, washed wool and wool fabric. It is 12% in flax, 13% in mohair, 11% in silk, 13% in viscose, 5% in polyamide, 0.4% in polyester, 1.5% in orlon. % moisture is the ratio of the amount of water absorbed by the textile material to the weight of the moist material.
In spinning mills, it is necessary to process the product (yarn) with minimum waste and high efficiency. In order to protect the twist, reduce the hairiness rate and prevent the loss of strength, the moisture values of the yarn must be in certain amounts. Humidity is also very important in the buying and selling of yarn. For these reasons, the moisture control of the yarn is made.
Conditioning is done to bring the bobbin yarn to standard atmospheric conditions. Commercial humidity is packaged as 8,5%. At the same time, the necessary moisture is given to the yarn.
There are different moisture measurement methods in bobbin yarns. The most common and practical ones are portable humidity measuring devices. The device we use in our measurements is such a device, the "Moistmeter" humidity measuring device. The humidity measuring device has two measuring ranges, “LOW-low” and “HIGH-high”.
COIL DIAMETER AND WEIGHT CONTROL
In order to ensure that each of the coils can be produced in the desired diameter and weight, the coil diameter and weight are checked. The bobbins taken from the bobbins produced in the bobbin machine in order to control their diameter and weight are called sample bobbins. At least five numbered bobbin samples are taken from the working bobbin machines according to the yarn quality plan. Filled coil samples whose filling time is completed are selected. The spindle (baraban) numbers are written inside and brought to the laboratory. It is ensured that the filled coils get the desired humidity by keeping them in the laboratory environment for at least 24 hours. The bobbin is formed according to the desired thread length or bobbin diameter. In both cases, the maximum coil diameter should average 320 mm.
Posted by %AM, 10% 414% 2016 10%:%Mar in Yarn Read 5760 times