It is the machine that removes the unevenness of the band coming from the carding machine and ensures the cleaning of the flies formed during the drawing.
DUTIES OF THE DRAWING MACHINE
1-To obtain a homogeneous band by combining (at least two – maximum eight) bands crosswise by dubbing (folding)
2- Pulling and thinning or condensing the comb bands by means of roller pairs rotating at different speeds
3- Correcting the hooked structure at the ends of the fiber (the rear end of the fiber is corrected in the first passage, and the other rear end of the fiber is fixed in the second passage).
4-To obtain traction bands in the desired number
5- Stacking the obtained band in buckets spirally with the coiler device.
In general, the working principle of the draw frame is examined in three parts:
Belt feeding-creel part
The characteristics of the sliver coming out of each card are unique. The slivers are brought to the full state by giving numbers to the draw frame, carding cans or by tying the slivers. As a result of this process, the bands to be connected to the creel part are arranged in such a way that the same comb buckets do not come together. This process is called crossover. Thus, the targeted homogeneous mixing ratios are one step closer.
The slivers from the cans are transferred to the draw frame drafting section by sliding them over a table or passing them through a pair of rotating carrier metal rollers. The roller pairs not only carry the band in a certain order, but also act as a switch when the band breaks, and stop the machine.
In general, 6 to 8 duplications are made on drawframes. More than one tape is sent to the draw frame at the same time and drawn as a single tape.
The drafting assemblies consist of 3 or 4 roller pairs. These cylinder pairs are.increment distance.
The distance between two cylinders is called the gauge distance. The retraction distance is adjusted according to the average fiber length. Pull; it means that the front roller rotates faster than the rear roller, but as an exception, condensation operations can also be performed on the servo motor draw frames. to thin the fiber by pulling, to make the fiber parallel to each other and to open the hooks at the ends of the fiber due to its natural structure.
Drawing devices in draw frames; It consists of drafting shaft, printing cylinders, gauge distance, drafting force, factors affecting drafting and air suction units.
Draft shaft (grooved transport roller):
It is made of hardened and helical grooves parallel to the axis. The reason for using grooved cylinders is to provide a more controlled transport of the material and to open the hooks at the fiber ends.
Pressure rollers (sleeve):
They are rollers with a certain shor hardness, synthetic on the top, between the grooved rollers and the pressure gun. The position of the sleeve is in different places on each draw frame. The sleeves are slotted into the pressure gun or on the draft rollers. Generally, cot diameters, rear and front draft cots are the same diameters. The diameter of the front drafting sleeve is slightly smaller. It gets its motions from the drafting rollers.
Gauge distance (setting)
Briefly; The distance between two cylinders is called gauge setting (distance). The gauge distance is adjusted according to the average fiber length.Epurpose in kartman setting; to minimize fiber breakage and to clean the fibers and small particles shorter than the gauge distance through the upper and lower air suction systems in the drafting box.
If the gauge adjustment is shorter than the average fiber length, the long fiber will wind up on the cots or break, which will cause unevenness problems. If it is wider, drafting will not take place between the rollers. Because when the rear roller leaves the fiber in the form of drafting, the front roller should be able to hold the fiber. Before the rollers release the fiber, the fiber should be slightly stretched so that the fiber hook ends can be opened.
gravitational force (pressure gun force)
The amount of pressure in the drafting box that allows the fiber between the drafting rollers and the sleeves to be drawn is called the drafting force. The pulling force setting varies according to the tape number. As the tape number gets thicker, the gravitational force should also increase. The amount of pressure in the drafting box increases or decreases according to the parallelism of the fibers and the instantaneous number fluctuation of the incoming band. As the gauge distance widens, the amount of pressure decreases. Because if wide retraction is done, it means fine thread will be made. For fine yarn, tape with a minimum of short fibers will be used.
Factors affecting shooting
The factors affecting the shooting process can be listed as follows:
1-Pinch or gripping point between the rollers
2-The circumferential speeds of the cylinders
3- Retraction distance between cylinders
4-Ribbling ratios of the lower drafting rollers
5-Surface hardness of printing cots
6-The distribution of gravity along the cylinder surface
7-The number of the tape at the entrance
Winding part (outlet device) on the draw frame
The belt, which comes from the pre-drawing roller in the form of cheesecloth, passes through the band funnel, passes through the calender roller pair and the turntable (gooseneck), and is filled into the buckets in desired quantities, generally circularly, via the bucket table.
The task of the tape funnel
Nickel-plated steel or aluminum metal is designed not to affect the direction change of the fiber and re-bands the fiber assembly in the form of muslin. The volume of the new tape is measured at the entrance of the funnel with the pneumatic system or the electrical system, and the volume of the ascending tape is transmitted to the probe rollers at the entrance. Thus, it is expected that the servo motors will adjust the band number given to the machine memory. The volume of the new band is measured at the entrance of the hopper with the pneumatic system or the electrical system, and the volume of the ascending band is transmitted to the probe rollers at the entrance. Thus, the servo motors are expected to adjust the band number given to the machine memory.
Calender roller pair
It consists of two inwardly rotating rollers or roller pair discs with a grooved top. Mission; It is to compress the band coming out of the hopper and transmit it to the rotary table in a certain form, tension and speed. Thus, band accumulation in the funnel is prevented.
The belt coming to the turntable is passed through a nickel-plated bent metal pipe resembling a gooseneck and wrapped in buckets. The length of the bent pipe is about 50 cm. The band moves through the pipe at an average speed of 1000 meters/minute along this distance. Since there is no area where the dust particles that occur due to friction can escape from the high speed moving belt, these dust particles accumulate at the gooseneck pipe outlet and are sent to the next machine with the band wrapped at the top when the bucket is filled and removed. These dusts are cleaned by the workers, but this process causes a waste of time. The tape coming from the gooseneck inside the buckets is usually wrapped in a circular manner at the desired diameter. The diameter of the winding into the bucket is realized by the adjustable lower bucket winding mechanism under the bucket.
MAKING FRAME BAND IN WOOL SPINNING
Pull tape has an important place in wool spinning. For this reason, the number of folding (dubbing) becomes directly important. This also plays a big role in the unevenness.
Purpose of Making Tensile Tape
With the bands obtained from the wool comb, the process applied to give more direction to the fiber, to straighten the fibers and to facilitate combing, to balance and smooth the weights of the bands per unit length, to obtain bands of certain fineness, and the machines used for this purpose are called drawing machines. Each applied drawing is also called a passage..The belts coming out of the carding machine are fed to the drawing machines as tops or by buckets; those coming from the carding machine are fed by buckets.
DUTIES OF THE DRAWER IN WOOL SPINNING
1- To reduce number deviations by minimizing unevenness by bringing together the thin and thick parts of the bands fed randomly with the help of folding (dubbing).
2-By bringing together more than one band with the help of folding, ensuring that the mixture becomes homogeneous.
3-To provide the mixture by bringing together different types and colors of fiber bands with the help of folding.
4-To open the fiber hooks in both directions by passing the fiber through at least two drafting machines.
5-Thinning the tapes at every stage with the help of shooting.
6-Band is to achieve.
The tapes from the cans and tops are fed into the drafting section through the feeding table and through the feeding roller. The bands fed by joining to the drafting part are pulled and turned into fiber tulle. It is fed into the band hopper smoothly over the delivery plate. The fibers in the form of gauze are transferred to the bucket by means of the receiving rollers by re-entering the form of a band in the band funnel. Drawing machines used in wool spinning, because the wool fiber is a long staple fiber, the drafting zone of the machine is long. Various elements have been used to provide fiber control to the elongated drafting region. These elements can be in the form of chain helmets or cylinders.