Roving Frame Workflow and Related Calculation

 

As an important production equipment of cotton mill, roving frame belongs to the preparation process from combed sliver to spinning into yarn in the production process. Roving production is the last of the preparatory stages for spinning.
The tasks of the roving production
 (1) Drafting the sliver to a finer one whose weight per unit length is made to allow a draft at the ring frame in the approximate range of 4 to 12;
(2) Using two suspended flyers to inserting few twists to the roving to make it strong enough to sustain the tension in further processing;
(3) Winding roving into the bobbin in proper way.

Drafting

The drafting system is the key to the rubbed roving frame, which adopts 3- roller -2-apron drafting arrangement can make the friction boundary distribution reasonable, the floating zone is small, can effectively control the fiber movement, the total draft multiple is high, and the roving eveness is good.
The bottom rollers are fluted steel and the top rollers are covered with synthetic rubber. When the top pendulum is latched down, springs are, compressed to apply pressure on the top rollers for good, strong contact with the bottom rollers. Located in the front draft zone are top and bottom aprons, necessary to suppress drafting waves caused by roller drafting.
Drafting roller spacing is the distance between the nip lines of successive roller pairs. This distance, as with all roller drafting systems, is adjustable to accommodate the fiber length to be drafted. Total draft is determined by the surface speeds of the back and front roller pairs. The draft in the back zone is referred to as break draft, and it should be as low as feasible so that the largest portion of the total draft will take place in the front zone where apron control of fiber movement is located. Most roving frames are designed to allow a large range in total draft from 4 to 20 and above. A more practical range 4 to 12 has been found to yield a better quality product.

Twisting

The suspended flyer is a twisting mechanism, and the suspended flyer turns once and adds a twisting. Doffer does not need to pull out the flyer, easy to operate, reduce the work intensity, is conducive to automation. Good rigidity, high rotation stability, suitable for high speed and large roll.
Twist multiple in roving should be sufficient to prevent stretching of the strand in normal handing and in its travel in the spinning creel. The method of calculating the twist in roving is to relate flyer speed to the velocity of the strand exiting the front roller:
In roving production, a combined twist insertion and bobbin build device is used to insert twist to the attenuated strand, and wind the roving into the bobbin.
More information about the roving frame can be found here.

Comments

Post a Comment

Popular posts from this blog

Twist Test Methods and Influencing Factors

Image
  Twist test is an important part of yarn inspection. It is related to the strength, elongation, appearance, style, etc. of yarns and fabrics. Different yarns have different structural characteristics, and their twist testing methods are also different. Basic concept To understand twist testing, you must first understand what twisting is. Twisting is a necessary condition for yarn formation. Short fibers can be made into yarns with certain physical and mechanical properties through twisting; filaments often need to be twisted in order to increase the tightness between single filaments, facilitate processing, and improve fabric properties. Number of twists Twisting is to cause two cross-sections of parallel straight fiber slivers to rotate relative to each other. The number of relative rotations of the two cross-sections is called the number of twists. Twist Twist refers to the number of twists per unit length of yarn . Twist coefficient In actual production, the twist coefficient is of
Read more

Combing Process in Spinning

Image
Before processing cotton, wool, and silk fibers into fabrics, the process of removing impurities and short fibers in the fibers with a combing machine is called combing. The texture, washability and durability of the fabric produced through this process are greatly improved compared with carded fabrics. The following introduces the composition of the combing machine and the combing process. The kinematic coordination relationship of the main parts on the combing machine is indicated by a dial. The disc is mounted on the combing machine and rotates synchronously with the cylinder, which is generally called the indexing disc. The index plate is divided into 40 equal parts along the circumference, and each equal part is 9°, which becomes one index. The working cycle refers to the time interval between the combing cylinder of the intermittent combing machine corresponding to the two actions of combing the whiskers. That is: the first row of needles in the combing cylinder goes to the botto
Read more

Garment Dyeing-Special Dyeing Method In Textile

Image
Garment dyeing is a relatively special dyeing process for textiles and garments. Many people may not know much about this dyeing process. In the impression of most people, textile and clothing products are dyed in the fabric period, and garment dyeing is a dyeing process that breaks people’s cognitive limitations on textile dyeing. ​What is garment dyeing ​Garment dyeing means that dyeing the one not in the fabric type but in the garment type itself. The garment type mentioned above include socks, towels, sportswear, shirts, plush toys (without fillers), T-shirts, pants, bathrobes, handkerchiefs, bath mats, carpets, scarves, etc. The material of these garments can be wool, linen, silk and cotton of natural fibers. But most garments are made of cotton or a cotton-rich blends. Garment dyeing imparts vibrant colors to garments. The clothes such as denim garments, tops, sportswear and casual clothing with garment dyeing can provide a distinctive special effect. Garment dyeing method Garmen
Read more