With the increase in technological developments, people's lifestyles, relationships, living standards and expectations are also increasing. Accordingly, the ability of companies to maintain and strengthen their competitive positions, both in the textile sector and in other sectors, depends on their ability to base their growth and productivity gains and to create new areas of comparative advantage.
While the race to create new areas and products by utilizing advanced technology while developing, industrializing and industrializing technology reaches an advanced level day by day, the power achieved in this way brings a great competitive field for nations in the world markets. The basic conditions of being successful in this race become clear as continuous quality, access to advanced technology, richness in product variety, educated and qualified workforce and cheap cost. In other words, instead of a raw material and labor-intensive industry, a quality-dominated industrial approach is dominant, based on owning knowledge, technology, both through production, development and transfer.
In the textile and apparel sectors;
To increase product quality,
Creating a new market
Reducing labor cost,
To increase the product variety,
Creating a market abroad,
To comply with the requirements of standards and legislation,
To increase production flexibility,
reduce energy consumption,
To reduce environmental pollution,
Reducing raw material consumption,
Developing new products to replace outdated products
If desired, companies must attach importance to technological innovation and R&D activities.
Finishing and dyeing processes are carried out in order to improve the appearance, attitude and usage properties of textile materials. Coloring processes, which are carried out in order to create more attractiveness on textile surfaces and to create an allure, are done by dyeing and printing. The dyeing of the yarns is done in four different ways: dyeing on bobbin, hank dyeing, bell dyeing and warp beam dyeing.
Bobbin dyeing is the most common area of use in terms of both its low cost and ease of application. Even though bobbin dyed yarns do not have the softness and bulkiness of hank dyed yarns, they can be sent to weaving as they are without requiring additional processing after dyeing, can be worked at lower liquor ratios, can dye large batches at once, and have the ability to dye all kinds of fibers with all kinds of dyestuffs in HT boilers. .
It is the dyeing of the yarns as coiled with cross winding on special bosses for dyeing. The dyeing of the crossbows is carried out in universal dyeing apparatuses. That is, the coil is stationary, the liquor is moving. Wrapped bobbins are placed on the dyeing machine, in which the dye solution moves from the center to the outside and from the outside to the center. Coil dyeing is done in various dyeing apparatus. Painting apparatuses are made in cylindrical form and can be used vertically or horizontally. The bobbins to be prepared for bobbin dyeing must first be wound with the required winding properties in the winding process. According to the properties of the yarn to be dyed, in the winding process, which is a preliminary preparation process, the yarn is wound in forms where the dye can penetrate and sent to dyeing.
The winding process is the transfer of the yarn from the bobbin or bobbin it is wound to another bobbin. After the yarns are produced, they are wound on cops or on bobbins as in the open-end spinning system.
After this stage, there are two ways to yarn;
• Either it will be presented to the market as a final product.
• Or it will be handled as an intermediate product within the enterprise and sent to the appropriate production stages (weaving, knitting, ready-made yarn and other production departments).
If it is to be put on the market as raw yarn, since it cannot be sold in cops, the winding process is carried out in order to present it to the customer in a suitable way. Cops from the yarn circle contain 100–150 g of yarn. There are some faults on these cops such as thick joints, thin and thick places, foreign materials such as cocoon and shell pieces, flies, tension differences. All these reduce the efficiency during weaving or knitting and cause faulty surfaces and unevenness in the woven or knitted fabric. For this reason, the cops coming out of the spinning machine are subjected to the winding process as the first step of the preparation process before weaving or knitting.
Purpose of coiling
In general, the main purpose of bobbin winding is to prepare bobbins containing large and same length threads for further processing, to remove foreign materials, errors that occur during spinning, and to eliminate unevenness in the thread diameter.
The main bugs fixed during coiling are:
• Thin and thick places in the yarn:
The thick parts of the yarn are the less twisted regions. For this reason, their strength is low and they cause breaks in the weaving. If they do not break during weaving, they create defects in the fabric. The thin parts in the yarn are the places where the fiber is low or the twist is high. They cause breakouts or fabric defects. The knots on the thread can be of different sizes. In this case, the warp thread does not pass through the lamellas, breaks or causes excessive friction. If used in knitting, it can cause yarn breaks and needle breakage.
• Insertion errors from the spinning mill:
In the spinning mill, first a double-wound part and then a thick part occur as a piecing error, which occurs after a break during spinning. This error occurs because the end taken from the non-spun part during breakage is placed under the yarn delivery cylinder together with the other end and delivered.
• Fly wrapped in yarn:
This error is caused by the fly in the spinning mill mixing with the yarn.
• Vegetable and animal wastes (nopes):
These are residues that can reach from the bale to the yarn, creating a weaving error.
Postures are of great importance in warping machines. A break in the plain warp represents the stop of 500 to 800 threads that are warped at the same time. This greatly reduces the efficiency of the warp. It is unthinkable to work from cop in warping machine. Because the cops often run out, cop changing operations will take a lot of time. At the same time, these stops will reduce the quality of the warp. In order to eliminate this negativity, it is wound into properly shaped bobbins whose weight is 10-20 times more than the yarn weight in the bobbins and which is easier to unwind. In weaving machines without a shuttle, the weft thread can be thrown without stopping for a long time, but only by using a large bobbin. Likewise, high-efficiency operation is possible in the folded winding machines by using the coil. The waxing process required for knitting yarns is also provided by winding. Therefore, it is very important to perform the winding process.
Points to be considered in the winding process:
Colored bosses designated for color, quality and number separation should definitely be used.
The setting and tension chosen for each type of yarn must be meticulously maintained.
Cleaning of flats and machines should be done frequently.
In non-automatic machines, knots should be tied small and firm.
With the empty spinning of the bobbins, the thread should not be frayed.
Care should be taken to ensure proper winding in the coil.
Periodic maintenance of the machines should be regular.
Possible errors in the coil and their causes:
Mixing of foreign materials into the coils. This error is usually due to the carelessness of the worker.
The coil is not wound properly. This error is mostly due to the faulty and out-of-adjustment of the winding mechanism.
Very small or large coils. The size setting of the coil diameter is out of order or the coils up to a certain size have not been removed by the worker.
Soft wound coils. It is caused by not giving the necessary tension to the yarn.
Coils in the big knot. It is caused by the worker not properly tying the knot.
Mixed yarn wound bobbins. It is a mistake made by the worker as a result of carelessness.
Coils with defective bosses. It is worker error and causes confusion in further processing.
Oily and dirty coils. It is the worker's fault, it requires attention and meticulousness.
Winding properties in winding
In the winding process, there are some parameters for the winding process and the coil. These vary according to the winding purpose. These parameters directly affect the quality of the bobbin, the winding process and the efficiency of the winding machine.
The main winding features are:
• Crossover angle
• Winding angle
• Yarn number
• Winding density and winding stiffness
• Coil shape and dimensions
• Yarn length in winding
Coil winding machines
Coil winding machines According to the basic winding shape;
- • Parallel winding,
- • Cross-winding machines
According to the coil shape;
- • Cylindrical coil,
- • Conical coil machines
According to the type of yarn walker;
- • Propeller blades
- • Slit blades
- • Grooved cylinder
- • Coiling machines
According to the purpose of coiling;
- • Coarse winding
- • Precision winding machines
They are grouped as
Machine elements in conventional winding machines;
yarn probe, yarn clearing knife, yarn brake, balloon breaker, bobbin spindle, waxing device, bobbin transport device, suction equipment for flies.
In semi-automatic winding machines; Yarn knots and cop changing are done by machine.
In fully automatic winding machines; A full cop is placed instead of the finished cop, and the end of the cop is found and connected to the bobbin.
In some machines, the full bobbin is removed and replaced with a new boss. End tying and cop changing is done by the knotting robot, and bobbin changing is done by the changing robot.
Bobbins prepared for dyeing
The winding structure of the yarns prepared for dyeing and the structure of the wrapped boss are at the forefront of the processes that affect dyeing. In addition, dyeing regime and dyestuffs are important parameters for dyeing process.
The winding structure is defined as the structure obtained by wrapping a material around a winding tool under certain conditions and prepared for use in subsequent processes. The winding structure is a technical structure created not only in the textile industry, but also in other technical industrial areas and used according to its purpose.
For example, in textile and apparel, wadding, tops, hank, ball, bobbin, bobbin, beam, various yarn-wrapped structures used in sewing machines, fabric and paper balls wound in rolls, cable reels of different sizes, various wire-wrapped structures produced and used in electronics and electrotechnical fields There are winding structures such as tape-wrapped film and other purpose cassettes, rope-wrapped structures used in hoists.
The concept of winding structure is a concept that includes the essence of textile and is among the basic subjects in textile technology. Because, from the beginning to the end of the technological stages in spinning, weaving and knitting production, material changes and winding-unwinding and unwinding-winding processes are carried out at every stage. These processes, on the other hand, are carried out by using winding structures with various features, which are semi-finished or ready-made products of the production stages. The poor quality or faulty of these structures negatively affects their use, production or service in the next stages.
Especially the winding structure; It is seen that the quality of the dyed yarn in the bobbin dyeing and finishing processes has a significant effect on the yarn waste and the efficiency of the production. When the winding material, the equipment that performs the winding, the winding conditions and the usage conditions of the winding structure change (which is taking place at a rapid pace today), it is important to improve the quality by developing the winding structure accordingly. Therefore, it is seen that it is important that research and development studies are carried out continuously on the subject of winding structure.
There are special dyeing bosses for winding the coils. Some of these bosses are flexible, some are not. Flexible ones are used for winding very shrinking yarns. The yarn, whose weight is between 500-1500 gr, is wound on conical or cylindrical cross bobbins.
It is important that all sides of the winding are at the same frequency and that the sizes of the windings to be dyed in one batch are equal. While preparing the windings, it should be ensured that they are not too tight, considering that the threads will shrink and swell more or less.
For example, cotton threads are wound with loose tension.
Since swelling will be higher in regenerated cellulose fibers, care should be taken to ensure that they are wrapped loosely and that the wrapping thickness is less.
Wool can be wrapped tightly as it stretches with water and heat.
In synthetic yarns, on the other hand, since the shrinkage is high due to the temperature, the yarn is either drawn first, then rewound and dyed, or it can be wrapped in special elastic bosses so that the pattern can shrink and not get too tight as a result of drawing. In case of different winding densities, the liquor will pass through the loose part of the winding and this part will be dyed dark. It will be difficult for the liquor to pass through very tight windings.
After the windings are made, it is ensured that the crossed bobbins are bent by pressing them from the top and bottom before placing them on the apparatus. Process; In principle, it starts with placing the coils on metal tubes of equal diameter with the coil core and on which holes are drilled in a row. Metal tubes are connected to the liquor circulation system and the dyestuff solution inside the tank can be circulated through the coils both inside-out and outside-in. In coil dyeing, it is important to place equal length bobbins on all dyeing rods.
Factors affecting the dyeing process of yarns on the bobbin
• Type of dyed yarn
• Type and quality of dyestuff used
• Parameters of the dyeing process (dyeing ambient conditions
• Painting process
• The temperature of the dye solution
• Circulation speed
• Circulation method
• Pumping pressure
• Technical parameters of the painting apparatus)
• The quality of the winding structure of the coils
• The surface structure of the boss.
The winding structure of the bobbins used for dyeing should ensure that the dye solution is distributed evenly throughout the winding. For this, the winding density of the bobbins prepared for dyeing should be less than the hard bobbins. According to the researches, the optimal value of the winding density of the coils was found to be around 0,33-0,37 gr/cm3 (Gordeyev and Volkov 1974). However, when dyeing regime under high pressure is applied, the winding density of the coil can be increased up to 0-39 gr/cm0,40. Therefore, examining the winding structure of the bobbins prepared for dyeing, especially determining the optimal values of the factors affecting the winding density, is very important for dyeing.
Important features that determine the winding structure of the coil;
• Raising (winding) angle of the yarn during winding
• Cross angle of the yarn coils in winding
• Density of the winding structure (specific gravity of the winding)
• Type and number of wound yarn
• Winding type (precision winding, ordinary winding)
• Shape and dimensions of the winding structure
During bobbin dyeing and finishing processes, the most important factor affecting the dyeing and drying quality is the winding density of the bobbin. The winding density varies depending on the type of yarn, the value of the cross angle, the tension of the yarn during winding and the pressure of the yarn loops. There are many methods and devices for determining the winding density. Density is determined by indirect and theoretical methods, usually by direct measurement.