In carding, different organs rotated at different speeds, which affected the quality of the silver. As fibers are opened with blow room and fed to card in the tuft form, they are opened again, and individualization takes place between cylinders and flats, before being converted into slivers. To obtain better sliver quality, the setting parameters of the card and the machinery conditions are important. Even small deviations in the settings and speeds of the machinery can produce inferior sliver quality. card clothing and card setting is a important task in cotton spinning. I this article, I will brief describe major setting point of the carding machine and different card clothing that are used in carding machine.
- To know about different setting distance of carding machine.
- Effect of carding setting on fibre.
- Different carding clothing name.
- To come to learn different carding clothing method.
Major Setting Points in Carding Machine:
|Setting distance(thou)/1thou= 1/1000 𝑖𝑛𝑐ℎ
|Feed plate to taker-in
|Taker-in to cylinder
|Flat to cylinder
|Doffer to cylinder
|Doffer com to doffer
|Mote knives to taker-in
|Upper knives(10 thou) lower knives(12-15 thou)
|Cylinder under casing to cylinder
|Back-12 thou, Middle-32 thou, Front-64 thou
Effect of Card Setting:
1. Feed Plate to Taker-in(9-12thou):
The object of this setting is to detach cotton in very small tufts form the lap without damaging the fiber. The setting varies with the staple length of cotton, hank of lap and the speed of taker-in. if the setting is too close the longer fibres will be damaged and the waste will increase. If it is too wide it results in plucking of lap with insufficient opening ,large tufts in the taker-in.
2. Taker-in to Cylinder (7 thou):
The object of this setting is to transfer the fibers to the cylinder and enable the taker-in to present cleans teeth to the lap fringe. An unreasonably wide setting would not ensure removal of the cotton from the taker-in and in an extreme case, if the taker-in became covered with cotton, its action of taking small tufts of material from the lap which would be performed inefficiently, and nep would be formed.
3. Flat to Cylinder (10 thou):
The object of this setting is to card the fibers well so as to produce clean web hold. A close setting tens to produce cleanser web, where as an excessively wide setting results in insufficient removal of nep and a poor appearance of the web.
4. Doffer to Cylinder(5 thou):
The object of this setting is to take all good cotton from cylinder to doffer. A wider setting makes many fibers go found the cylinder unnecessarily more times and they get weakened by the time they are transferred to doffer and a patch or cloudy web will result. The closer setting will damage each other and leading hook may result.
5. Doffer Comb to Doffer(12-15):
The object of this setting is to remove as much good fibers as possible without touching. The setting should be sufficiently close to remove as much good staple fiber as possible but if it is too close contact between the comb teeth and doffer wire may occur, leading the offer wires being damaged and the comb teeth may worn away. For heavy sliver production the setting may be increased slightly.
6. Mote Knives to Taker-in:
The setting should be sufficiently close to remove heavy impurities on the taker-in surface. If the setting is too close, loss of good fiber may occur and if it is too wide the mote knives operate inefficiently.
7. Cylinder Under Casing to Cylinder:
These setting influence air currents and production of fly. Too wide setting causes loss of good fiber.
On the other hand, card clothing contributes significantly to the quality of yarn. The term ‘card clothing’ refers to a continuous length of ‘wire’ containing teeth wound under tension on a plain cylinder and secured at the ends. In cross-section, the wire is shaped like an L with teeth upstanding. The base establishes the spacing between the teeth across the width of the cylinder by forming a foundation in contact with it. The bottom of the L-shaped wire rests on the cylinder’s periphery. Because the tips of the teeth need to be hard enough to withstand wear, careful heat treatment is necessary during manufacture of the wire. As a result, the metal becomes brittle, so tempering is necessary for the main body of the tooth to maintain its toughness.
There are three types of card clothing:
- Flexible Card Clothing.
- Semi-rigid Card Clothing.
- Metallic Card Clothing.
1. Flexible Card Clothing:
This feature is composed of round or oval wire hooks attached to an elasticized, multi-ply cloth backing. Hooks are bent into a U-shape and have a knww that flexes under bending loads and returns to its original position after the load is removed. In short-staple spinning mills, this clothing is now found only on card flats.
2. Semi-rigid Card Clothing:
The wires are set in a backing that is less elastic than flexible clothing, so they have square or round cross-sections and sharp points. This backing comprises multiple plies, including layers of cloth and plastic, compared to the backing of flexible clothing. Wires with flat surfaces do not have knees, but wires with round surfaces may have them. In addition to being unable to bend, the wires are embedded so deeply in layers of cloth and foamed material that they are virtually immovable. Because they are less flexible than flexible clothing, they do not yield under bending loads. In addition, they can only be found on flats.
3. Metallic Card Clothing:
In these self-supporting, circular wire structures, teeth are cut at the smallest spacing possible by a process resembling punching. The clothing is referred to as saw-tooth clothing if the teeth are relatively large, as in licker-ins. Today, metallic card clothing is used on the licker-in, main cylinder, and doffer.
A carding machine’s taker-in, cylinder, doffer and flat are covered with fine, closely spaced and specially bended wires called card clothing. This experiment taught us how to set distances for card machines and different types of carding. Additionally, we learned about the effect of setting the distance of the carding machine. It will be helpful for our future lives if we conduct this experiment.
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- Klein, W. (2019). The Rieter Manual of Spinning. Switzerland: Rieter Machine Works Ltd.