There is no doubt that the draw frame is the quality filter of the spinning mill. When there is a mistake in the sliver of the draw frame, there will be defects in the yarn as a result. Thus, quality cannot be improved after the draw frame, meaning that sliver quality must be monitored carefully, metre by metre, at the last passage of the draw frame to ensure that the quality of the slivers meet the self-set quality standards at the drawing frame point.
- To know about draw frame.
- To learn important task of draw frame.
- To know passage diagram of draw frame.
- Come learn different parts name of draw frame.
Some important task of draw frame:
The draw frame plays an important role in improving equal ness over short, medium, and long-term variations. Drawing is always equalized by doubling and can be equalized by auto-leveling an optional second process.
2. Parallelizing and straightening:
The fibers in the yarn must be arranged parallel to one another for the yarn to have optimum strength. To create this parallel arrangement the draw frame is responsible for creating it. As a result of every drafting step, it accomplishes this task by straightening the fabric’s fibers using the draft method.
3. Fiber orientation:
A sliver of fiber from a carding machine is oriented in all directions, contains a leading and trailing hook, and is crimped. During drawing, these un-oriented fibers become oriented towards the sliver’s axis. It is achieved by drafting in the draw frame method.
Although modern blow room processes can achieve through blending, blending after carding improves the fiber composition of the sliver. When several slivers are fed through a draw frame and recombined at the front, the fibers in the individual slivers are blended well, resulting in a more uniform fiber composition across the length of the final sliver than a card sliver.
5. Dust removal:
During drawing, there is a high level of friction between fibers and fiber and metals during the drafting process, which makes the draw frame a good dust-removing machine. The dust from the incoming air is more than 80% on high-performance draw frames equipped with appropriate suction or removal systems.
Some important draw frame terms:
It is one of the processes used to manufacture yarn to draw the yarn after it has been carded. The share of drawing cost in yarn cost has minimal effect on the production cost of yarn, but the drawing process (draw frame) plays a significant role in enhancing the quality of yarn in many ways, such as evenness, strength, elongation at break, and degree of hairiness, which are all essential factors in making yarns suitable.
A doubling process involves feeding two or more carded slivers together. As a result of the drawing process, a combined sliver of the same linear density is obtained. In the doubling process, six or eight slivers are usually combined into a single sliver. As a result, the resulting sliver is more uniform, and linear density has been improved. During doubling, how can the evenness of the sliver be improved? By applying the law of doubling, we can understand this.
In the process of drafting, the input sliver is weighed less per unit length. In the sliver, hooked and curled fibers are straightened, and fiber arrangement is improved by making fibers parallel along their length. In the drafting process, fibers are blended. Sliver dust is also eliminated through the drafting process. A pair of drafting rollers are used to perform the drafting action. The rollers rotate higher during the drafting process.
4. Creeling and Doffing:
The process of replacing the cans of feed material at the back of the machine and joining the new can of sliver with the old can is referred to as creeling, and the process of removing the full delivery cans from the front of the machine is referred to as donning.
1= Card sliver can
2= Pair roller.
3= Drafting arrangement.
5= Calendaring roller
6= Sliver passage.
7= Draw sliver can
Working Principle of Draw Frame:
The drafting arrangement (3) receives four to eight card slivers. Each card sliver can(1) is topped with a pair of fed rollers (2). Positive drive is used to drive the fed rollers. The slivers running into the drafting arrangement(3) .The slivers runs into the drafting arrangement, are subjected to a draft of 4 to 8 and leave it as a web and condensed into a sliver immediately. It is then required that this sliver of metal is guided through a tube (4) via a passage (6) of the tube gear and into a can (7), in which it has to be laid in clean coils utilizing as much of the space as possible within the can by compressing the sliver and passing it through calendaring rollers (5).
|Raw materials||Cotton, man-made fibers, blends, fiber length up to 60 mm|
|Doubling [fold]||up to 8|
|Feed [ktex]||12 – 50|
|Draft [fold]||4.0 – 11.6|
|Delivered sliver weight [ktex]||1.25 – 7.00|
|Delivery speed [m/min]||up to 1 200|
Draw Frames are machines that double or combine slivers, blend and mix them, and level and attenuate them transiently, through a series of pairs of rollers, all at once. It is important to note that each pair of rollers in the drafting arrangement moves faster than the previous pair. During this experiment, we learned how the drawing machine worked, what the parts were called, and how it worked. In the future, this will be helpful to us in our job field.