Carding machine; It is not only a machine in which the cotton in the form of fiber clusters is turned into a band, but also a machine that is at the center of the preparation process and determines the quality and production to a large extent.
DUTIES OF COTTON CARDING MACHINE
1- To open the fiber masses, which are turned into fiber lumps by opening in the blow room, until they become single fibers.
2-Removing the shell and core pieces, dust and dead fiber in the cotton mass.
3-Removing the short fiber.
4-Removing neps formed during ginning and blowroom transports.
5- To give the fiber a longitudinal direction and parallelize it.
6- To form a smooth comb band with no variation in number.
7- Stacking the obtained tape in the bucket in a regular manner.
The working principle of the carding machine is examined in three groups.
1- Feeding and pre-opening part
FEEDING AND PRE-OPENING SECTION
This part consists of pellet feeder, feed table, feed roller, licker-in, licker-in blades and licker-in screens. The raw material is fed into the machine chamber through a pipe channel. Properly compressed fiber is collected in the chamber. The fiber is conveyed to the feeding system with the feeding roller. This system delivers the fiber layer of the feed roller very slowly to the licker-in area. This transmission speed is low enough to have a holding effect relative to the peripheral speed of the licker-in. The saw-type teeth on the licker-in are at the frequency of 2-5 pieces per cm6. In cotton spinning, the licker-in with a diameter of 250 mm rotates at a speed of 900-1500 d/min per minute. The teeth of the licker-in clothing rip the fiber bundles from the cotton wad extending forward from the feed roller into small pieces with surface speed and take them to the surface. The fiber bundles engaged in the teeth of the licker-in are pulled down. First, it is conveyed forward over the grates by passing through one or two licker-in blades set very close to the licker-in. With the effect of centrifugal force created by the effect of the environmental velocity, some of the foreign materials in the opened fiber fall from the grid spaces and move away from the fiber. The task of the knife is to separate the cotton seed crumbs from the fiber. The blade, which is as long as 100 cm in width, is adjusted exactly parallel to the licker-in. The blade should be sharp and with a slippery surface. The task of the screen is to remove impurities in the fiber from the fiber, to prevent the loss of long fibers, to provide a relative control over the forward propulsion and airflow. The cotton layer spread on the clothing lined surface of the licker-in is 80% opened.
This part consists of drum grille, front back plate and caps. The circumferential speed of the large drum is approximately 100% higher than the circumferential speed of the licker-in. Due to this speed difference, the wires on the large drum strip the fiber attached to the teeth of the licker-in and take it to its surface. The drum is covered with different structure and finer wires. The distance between the licker-in and the drum wires should be set as close as possible to transport the fiber. Carding, one of the most important tasks of the carding machine, takes place between the large drum and the flats. The wires on the drum are steel clothing wires with little stretch. On the hat, there are flexible wires that are placed and mounted in layers. In the carding position, the wire directions of both elements are opposite to each other. With the effect of centrifugal force, foreign materials in the thin fiber layer are intensely pushed to the flats. The cotton layer, which is brought in the form of a thin tulle by the large drum wires, is opened as a single fiber by combing between the drum and flat wires due to the different wire directions and the superficial speed difference. Only 100-120 of 40-45 flats in a flat set are in carding position. Others move backwards to clean and recard. When the hats reach the front of the card, they are cleaned by a special brush comb. In other words, the short fibers and small foreign substances embedded between the wires on it are separated from the hats, these wastes are called hat waste.
The task of the screen under the big drum is to prevent the long fiber from spilling from the drum surface and to control the air flow. At the same time, very short fibers and foreign substances that are free in the material are poured out of the cavities of the grid with the effect of centrifugal force and move away from the cotton fiber.IR.
This part consists of doffer, saw (stripping, picking) rollers, printing cheesecloth rollers, calender rollers and coiler assembly. The cotton fiber is piled on the doffer after passing between the drum and the front plate. Its peripheral speed is very low compared to the speed of the drum. The directions of the metallic clothings on the drum and the doffer are opposite to each other. It also has the feature of working at low speed so that the amount of waste does not increase during the web bonding process.
It is a roller stripping system that takes the fiber from the doffer in the form of fine cheesecloth. The doffer is covered with fine wires. These separate and parallelize the fibers. The fine fiber gauze is taken by the receiving rollers and passed through the hopper and the pressure rollers to become a band.
EXIT FUNNEL AND CALENDER CYLINDERS
The delivery of the cheesecloth in the form of a band is carried out by the exit funnel and the squeezing (crushing) rollers. The crushing rollers placed between the stripping roller and the funnel where the band is formed affect the working conditions. These rollers crumble the core and shell fragments and deform the neps. As a result of the researches, it has been understood that collecting the cheesecloth as a band has a great effect on the foam-free operation of the carding machine. Particularly at the edges of the web, the impurities that disturb the band formation process by being taken away later by the web should not be collected. In the calender rollers, the cheesecloth is collected by the funnel and becomes a round strip. The diameter of the funnel is selected according to the desired band number in order to ensure smoothness.
COILER ( SCREW STACKER )
It is a mechanical arrangement that ensures the helical placement of the belt coming out of the carding machine into the carding bucket and while doing this, it tries to minimize the fiber mixing and unevenness that may occur during the unwinding of the belt. There is an upper rotary table connected to the machine chassis and moving, and a lower rotary table under the bucket. There is a coil-shaped spring in the comb buckets. This spring; It ensures that the distance between the clamping rollers of the belt and the filling point of the bucket remains constant throughout the entire placing process. Thus, since the belt is prevented from stretching with its own weight, the smoothness of the belt is preserved. The cleaned and rounded cotton fiber is properly looped with the coiler device and placed in the comb bucket.
SOME AND CAUSES OF FAULTS IN PRODUCTION IN THE REEDING MACHINE
1-Irregular edge on the web: If the width of the inlet lap is wider than the width of the drum, there will be flaking on the edges. Thus, the web edge deteriorates.
2-Edge floaters: If the drum grid is too narrow, irregularities will occur in the lap feeding. It occurs because the drum front and rear settings are broken and crooked.
3- Trash cheesecloth: It is caused by the unadjusted distance between the licker-in and the blade.
4-Cloud cheesecloth: It is caused by the change of the input number and the incorrect setting of the gauge at the entrance.
5-Band slip: It is caused by the uncontrolled attraction between the calender roller and the coiler rollers.
6-Excess rash: If the gauge adjustment of the flat is too wide, the flat clothing wires are damaged; This may be due to the fact that the flat cleaning apparatus does not do its job properly and that a high amount of waste is mixed into the blend.
7-Strip is uneven: The lap is uneven. The distance between the licker-in and the feeding table is too open, the licker-in wire is bent or blunt, the distance of the cheesecloth take-up roller to the doffer, and the excessive tension between the receiving roller and the coiler roller.