Yarn Breakage in Ring Frame: Mechanism, Reasons and Control
Md. Amir Khasru
B.Sc. in Textile Engineering
Department of Yarn Engineering, SARSTEC
Email: santo.amirkhasru2002@gmail.com
In the yarn manufacturing process, ring frame plays a vital role and it is the last step. A ring frame is used to produce yarn from roving fiber by drafting, twisting and winding. Yarn Breakage refers to the fault or cut of yarn for some reason. A ring refers to circle circle-shaped thing. In spinning, a circle-shaped ring is used to form yarn by rotating the fiber. Since there the Ring is used as the main constitution of spinning and so it is called Ring spinning or Ring Frame. [Fiber – Roving – Ring Frame – Yarn]
Figure 1: Ring and traveler of Saurer
Operation of Ring Frame:
Creeling: Hanging the roving bobbin into the creel.
Drafting: Through drafting the roving yarn is used to thin out.
Twisting: Twisting is used to form yarn from thin-out roving.
Winding: Twisted yarn is turned into a bobbin by winding.
Building: Giving the bobbin the proper desired shape for the next operation.
Doffing: Adding an empty bobbin and removing the winding bobbin is known as Doffing.
Figure 2: Ring Frame of Toyota
Type of Wastage in Ring Frame:
There are also many kinds of waste in ring frame. More than 1% wastage is not acceptable for a ring frame. We are mentioning some of them.
1. Soft waste (Useable)
Pneumatic waste 0.2% – 0.3 %
Bonda or roller waste 0.2% – 0.3 %
Roving waste 0.1% – 0.2%
Sweeping waste 0.2% – 0.3%
2. Hard waste (Un-useable)
Thread Waste 0.1% 0.2 %
3. Invisible waste (Un-useable)
Fly dust 0.1% – 0.3%
Pneumaphil waste: Pneumaphil is an impurity of the ring frame that does not warp in the bobbin throw yarn from the front roller.
Soft waste: The fiber’s forms of wastage in spinning are known as soft waste. Soft waste is reusable and used to make low-quality yarn.
Hard waste: The type of wastage is totally unusable without additional operations before use with soft waste is called Hard waste.
Invisible waste: Invisible waste is are type of loss that isn’t visible only measurable. The subtraction between net cotton consumption to net yarn production is invisible loss.
[Invisible loss = Net Cotton consumption–Net yarn production]
Figure 3: Ring frame of Rieter
Yarn Breakage or End Breakage in Ring Spinning: Yarn breakage is a major problem in spinning section. Breaking of yarn in ring frame is called end breakage in ring spinning. The breakage of yarn generally takes place just after the delivery from the front nip in the spinning zone between the thread guide and the front rollers’ nip. Yarn breakage take place due to imbalance in the tension imposed on the yarn and the yarn strength at the weakest portion. A very thin portion of yarn just after the delivery from the front nip also causes an end breakage in ring spinning.
End breakage in spinning reduces production efficiency and reason for fiber waste. Less breakage in ring means higher number of efficiency and less production cost waste. There are many reasons behind this.
Figure 4: Yarn after breaking by Eric Blond on researchgate
Theory of End Breakage During Tensile Testing: The mechanism of end breakage will offer a method to deal with end breakage to any conceivable degree. End breakage rate is an important spinning feature that affects both the maximum spindle speed and the quality of the yarn. Theory of the process via which yarn breaks in tensile tests. Yarn is virtually a multi-file cluster network with a 3-millimeter connection distance and the yarn’s link is where the separation occurs. When a yarn comes into contact to an external force, tension is created in the yarn, which is neutralized by friction resistance to avoid fiber slippage. As the ‘generates tension’ increases, the extension of the fiber increases, but a few weaker fibers with low extension may break at the weakest link in the yarn, reducing the load-bearing capacity of the surviving fibers. The weakest zone undergoes greater damage to fibers as the applied force gradually increases. The tension on the surviving fiber accumulates, allowing the rupture to spread more quickly throughout the cross-section. The surviving fibers’ load-bearing ability decreases, and the remaining intact fibers slide, causing the measured load to decrease, indicating yarn strength.
Mechanism of Yarn Breakage in Ring Frame:
Roving yarn is thinned by Drafting with Front Roller on Ring Frame and this thin yarn is twisted through Traveler to make yarn from roving fiber. The yarn obtained from the drafting zone is twisted with the traveler and wound on the bobbin. This knotted thread is used for further work. If the roving fiber obtained from the creel breaks up to the drafting roller for any reason, then it is called roving breakage. Similarly, if the yarn breaks from Roving yarn to Twisted Strong yarn, it is called yarn Breakage in spinning. In Ring Spinning Roving Yarn passed through drafting rollers. Back roller, Middle rollers and Front rollers are main drafting rollers. These rollers has draft the roving yarn when passes through yarn guide .The traveler help to twist the roving yarn and improved yarn strength and finally we get the required yarn. In this path, if some where and some how yarn got something wrong and cause yarn cut down and This cut down of yarn also known as yarn breakage. Yarn Breakage mainly happens between the front roller and the traveler Spindle of the bobbin rotate by motor which help in winding and finally yarns turned into bobbin.
Figure 5: Mechanism of Ring Frame
Reasons for Yarn Breakage in Ring Frame: There are two types of reasons for yarn breakage in spinning. Yarn breakage reduces production efficiency and financial loss for an industry. For better revenue must know the reason behind it and have to protest the reasons.
A. Mechanical Reasons:
1. Fault in the Drafting System: Faults in the Drafting System cause uneven drafting and sometimes miss drafts, which also cause yarn breakage.
2. Fault of gear and wheels: Faulty gear and wheels are responsible for the irregular speed of the ring frame. Irregular speeds mean irregular spindle and roller speeds, which cause yarn breakage.
3. Fault in apron: A fault in the roller apron causes a change in draft and produces less strong yarn, which is responsible for yarn breakage.
4. Spindle defect: The spindle is the main part of the ring frame; it helps in twisting and winding; it holds if defect occurs in their vibration; it has an incorrect center; and so many other problems are also present. These causes tend to cause yarn breakage.
Vibration
Wobbling
Incorrect Center
5. Damage or fault ring: Sometimes, the damage or fault ring cuts down the yarn and causes yarn faults.
6. Roving Breakage: Before drafting yarn, if the roving yarn breaks, the final yarn also breaks.
7. Slip of spindle tape: Spindle tape speed is also responsible for yarn breakage. Slips of spindle tape make the bobbin speed non-uniform, which also causes yarn breakage.
8. Feeding undrafted material: Feeding undrafted material reduces yarn strength and causes breakage very easily.
9. Thick and weak places in roving: Irregular drafting makes the roving thick and weak. Thick and weak places in roving are responsible for Yarn breakage.
10. Wrong setting of traveler: Wrong setting of traveler change the yarn dimensionally and break the yarn.
11. Double roving: Double roving opposes the twisting of yarn and reduces yarn strength.
12. More soft waste in mixing: Mixing of excess soft waste sometimes decreases yarn strength. Less strength means easy yarn breakage.
13. Some other problems:
Damage or a missing apron
Top roller cot problem
Incorrect spacers (between two aprons)
Misalignment of spindle tape
Wrong yarn guide (lappet) setting
B. Technical Reasons:
1. Unskilled operators and laborers: Operators and laborers not trained well for maintenance of the ring frame cause yarn breakage. Laborers should be trained first to get better results.
2. Bad (inferior) quality of roving materials: Bad quality of roving materials also causes roving faults and roving breaks. Roving faults cause yarn breakage.
3. More tension to roving due to improper position of creel: Improper setting of creels causes more tension in roving, which is responsible for yarn breakage.
4. Improper selection of ring and traveler: Improper selection of ring and traveler causes many problems in ring spinning. Due to improper selection, yarn breakage is the main phenomenon.
5. Incorrect bare bobbin diameter: If the bare bobbin diameter is lower, then yarn tension increases, and finally, higher yarn tension results in yarn breakage.
6. Incorrect roller setting: First of all, fiber breakage due to the closer roller setting is happed, and uneven yarn due to the wider roller setting occurs, which causes breakage.
7. Irregularity of yarn:
Thin place, less twist.
Thin place higher count.
Excessive short fiber in the roving.
Roving irregularity.
8. Improper humidity in the spinning department: The standard humidity and temperature of the spinning mill are 60%–65% RH and 32–35 °C, respectively. If humidity is lower than the standard value, static electricity will form. On the other hand, if humidity is increased, roller lapping forms; that’s improper humidity (RH)) and temperature, which cause yarn breakage.
9. Stretched roving:
Bad Creel
Faulty roving guide
Faulty building motion of the roving package during winding
10. Traveler fly out:
Worn out of travel
Improper flange selection
Higher spindle speed
11. More Yarn Tension: In general, tension should be 1 g/tax during twisting and winding. Increase in tension due to more traveler speed, excessive spindle speed, electric spindle, vibrating the spindle, and more ring diameter. Ring dia should be maintained with bobbin dia.
12. Excessive twist in roving:
Improper selection of TPI in roving causes more twists.
Less of a break draft.
How to Control Yarn Breakage in Ring Frame: To reduce yarn breaks, the following aspects should be taken. More than 3% breakage is not allowed. Less than 1% yarn breakage is okay.
Yarn breakage in the ring frame is connected to slippage of fiber at the spinning triangle for spinning tension peaks occurring in the fiber stand. A greater top roller pressure will improve the grip at the front drafting rollers. Using soft cots enhances the grip at the front rollers.
Ring and traveler friction reduction could decrease the peak tension during the rotation of the traveler..
Proper measurement is needed to reduce the mass irregularity of yarn straight after carding.
The front roller nip width should be reduced according to the spinning triangle.
The machine should be maintained regularly. Regular replacement of travelers, rings, and aprons according to an appropriate mechanical schedule.
Spinning speed in the ring frame should be maintained in relation to raw material selection. Spindle speed and traveler speed play vital roles in yarn breakage and end breakage. For cotton, a higher count needs a higher spindle speed to show higher production efficiency. 15, 20, 25, 30, and 40 Ne cotton at 12000, 13000, 14000, 16000, and 17000 rpm spindle speeds show 95% efficiency. In recent research, proper speed maintenance with yarn count has reduced end breakage (yarn breakage).
Twisting zones should be free from different kinds of disturbances. Centrifugal force, traveler’s gravitational force, dragging force, and other various forces act on the yarn at the twisting zone. Properly taking care of the twisting zone and making it free from all types of disturbances and selecting the right traveler number also reduces yarn breakage.
Relative humidity and temperature should be maintained. Low RH% will make the yarn brittle because there will not be inter-fiber coherence, and yarn breakage or end breakage will occur. Temperature should be 32°C to 35°C and RH up to 60%–65%.
Ring frame drafts should not exceed more than 40. More draft means more vibration. More vibration tends to cause yarn breakage.
The selection of a proper spacer reduces yarn breakage.
Conclusion:
In spinning, Ring frame play a vital role in yarn production. Here Roving to yarn is produced. There are many factors that affect spinning efficiency, and yarn breakage or end breakage is the most important factor in ring spinning. Too many reasons are responsible for yarn breakage, and it is impossible to avoid it, but we can reduce it. According to the study, understanding the proper reasons for yarn breakage, such as unskilled labor, excess soft waste mixture, thick and thin places in roving, and others,. Proper maintenance of the ring frame twisting zone, drafting zone, traveler, humidity, and temperature is possible to reduce yarn breakage.
Manual of Short Staple Spinning( Volume – II )– Mohammed Farhad Mahmud Chowdhury
Understanding Textiles for a Merchandiser – Engr. Shah Alimuzzaman Belal
Lecture Sheets of Short Staple Spinning -2 by Ashima Mollik, Lecturer SARSTEC.
Redwanul Islam, M., Chakrabortty, A., Ghosh, J., Iqbal, T., & Tanvir Hossen, M. (2021). Importance of spindle speed in ring frame. International Journal of Engineering & Technology, 10(2), 85-88.
Uddin, Md & Haque, Dr &Hasin, Dr & Hossain, H.M.Zakir. (2008). Identification of the critical factors of yarn breakage in ring spinning by design of experiment. 10. 66.
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