The roving quantification is an important process parameter of the roving process, and its deviation directly affects the quality of the yarn. Therefore, only by controlling the difference in roving weight within a certain range, the unevenness of the weight of the roving and the spun yarn can be reduced, and the quality of the yarn can be improved.
1 control the difference in weight of roving feeding sliver
During the feeding of the guide bar behind the roving frame, the sliver is not enough to withstand the tension between the self-weight elongation and the guide roller when it is taken out from the can, resulting in an unexpected elongation of the sliver (away from the rear roller) The two rows of slivers are called the rear row, and the two rows of slivers that are close to the rear roller are called the front row, and the accidental draft of the rear row of slivers is larger than the front row.
Therefore, in daily work, we must strengthen the maintenance of the guide frame part, make the guide roller run flexibly, reduce the tension draft between the rear roller and the guide roller, and reduce the accidental drafting generated during the feeding of the sliver.
The edge of the top hole of the roving frame of the roving machine to the front roller is the spinning section, and the depression of the front roller handle is small, which easily causes the unexpected elongation of the yarn.
The spinning section of the front row of the roving is long, and the depression area is also long. The roving strength is worse than that of the inner row, and the accidental elongation is also large. However, there is a big difference in the yarn guide angle between the inner and outer rows of the A456C roving frame, which makes the spindle difference of the A456C roving frame more prominent.
We have adopted a new high-efficiency false twister installed in the inner and outer rows to reduce the difference of the yarn guide angle and increase the twist of the spinning section. Due to the application of the new high-efficiency false twister, the length of the depression area is significantly shortened. The length of the depression area is shortened to increase the strength of the spinning spinning section, reduce the accidental elongation, and reduce the unevenness of the roving weight.
The roving machine will produce an unexpected elongation after the machine front, and we can reduce the unexpected elongation between the rovings by reasonable matching.
The matching method: the tampon in the back row corresponds to the roving spindle in the inner row, and the tampon in the front row corresponds to the roving spindle in the outer row, thereby adjusting the tension difference between the front and rear rows of barrels and the inner and outer rows of spindles during the spinning process, Reduce accidental elongation and reduce the weight difference between the roving frame ingot and the ingot.
2
Reduce roving tension differences
Since the strip of the front roller output is twisted into the stroke of the bobbin, the friction between the hollow arm of the top end of the flyer and the palm of the palm must be overcome.
For normal winding, the winding length of the bobbin should be slightly larger than the front roller output length, so that the roving maintains a certain degree of tension during the winding process. This tension is called roving tension. It is also a must in the process.
The roving tension has a great influence on the production. When the roving tension is not suitable, the elongation of the roving of each stage of the doffing is different. When it is wound, it will be too loose or tight, affecting the winding length and destroying the uniformity of the normal strip. At the same time, it will increase the roving break and defects, which seriously affect the product quality and output.
In addition, the roving breaks and other defects will also be increased during the unwinding of the spun yarn. In severe cases, the data of the yarns will be uneven, the CV value of the strip, the unevenness of the strands, the tension and other test items will deteriorate, exceeding the national and enterprise. Internal quality standards.
Therefore, attention should be paid to the design and adjustment of the roving tension, which is an important basis for the quality and output of the product.
The design and adjustment of the roving tension is determined by the influence of the raw material, number, twist, winding condition, moisture regain, temperature and humidity of the roving.
In the doffing process of the roving frame, the output speed of the front roller is constant, but the diameter of the roving wound on the bobbin is continuously increasing, and the winding speed of the roving is increased to affect the roving tension. The change, therefore, for each additional winding of the roving, the bevel wheel belt moves by one unit of movement to adjust the winding speed of the roving so that the winding line speed remains consistent with the front roller output speed.
3
Strictly control the temperature and humidity of the workshop to strengthen maintenance management
When the temperature of the workshop is high and the humidity is too large, the frictional resistance between the roving yarn and the machine increases, the winding tension increases, the increase of the winding diameter decreases, and the cohesion between the fibers increases due to the increase of the resurgence of the fiber. The relative slip caused by a certain external force is inevitably reduced, and it is reflected in the spinning section that the sliver is loose.
At this time, the tension is increased, the elongation is not necessarily increased, and the produced roving is loose, and the hairiness is significantly increased.
Now we have a large number of bobbin holes in the production line to expand and expand, and shake when the machine is turning; the outer diameter of the bobbin is different; there is bending deformation, which causes the roving elongation to be caused by the difference of the winding speed. These factors can increase the roving frame. The difference in elongation between the ingot and the ingot.
In order to reduce this difference, the inspection and repair work of the roving bobbin should be strengthened, and the outer diameter should be consistent. If the bobbin has obvious shaking, it should be scrapped in time.
When operating the car, the car must be operated according to the operating procedures and process requirements.
That is, the yarn guide holes at the upper end of the roving flyer must be divided into 1/4 or 3/4 according to the process requirements. After the perforated roving passes through the flyer channel to the palm press, it is also divided into single or double winding according to requirements. .
These two points must be operated according to the process requirements. This is solely to make the roving of the same type of the same type of friction on the flyer the same, so that the tension and elongation reach the relevant standards.
It is impossible to make the equipment without any defects, so the process must be properly formulated with the equipment, and the improper process will also cause problems. Simply starting from the equipment side does not eliminate the uneven weight of the roving.
Grasp the co-management, anti-micro-duration. In the case of reducing employment and increasing the number of watchers, it will inevitably increase the difficulty of production management. On the one hand, the equipment maintenance personnel should strengthen the patrol inspection force above, and the air-conditioning workers should rush to patrol, and adjust the temperature and humidity for the spinning difficult areas; more importantly, the shifting workers, the doffing workers, and the machine repairing When paying attention to the work, the workers pay attention to the problem and find out the problem in time.
To sum up, enterprises should establish a sound quality feedback system and find out that there are quality problems should be immediately feedback, and find the reasons to take measures in time.
In normal times, all departments should pay attention to controlling raw materials, quality, moisture regain, keeping the temperature and humidity in the workshop relatively stable, optimizing process parameters, reducing accidental drafting under the conditions of spinning process, controlling the quality of semi-products in each process, and ensuring qualified production. The roving is supplied to the subsequent processing and production.
