Reducing the breakage rate of yarn in the spinning machine is a complex project that involves multiple aspects such as raw materials, equipment, process, operation and environment. The breakage rate is a comprehensive indicator for evaluating the management and technical level of the spinning workshop.
The following are detailed measures and solutions sorted out for you from multiple perspectives:
1. Raw materials and semi-finished products (Prevention-oriented, Source Control)
There are many reasons for yarn breakage, and the quality control of semi-finished products is the foundation.
Quality of raw cotton: The blending of cotton should be stable and reasonable. Pay attention to indicators such as the fiber length, strength, fineness, maturity, and short fiber rate of the raw cotton. In particular, the short fiber rate. If it is too high, it will lead to poor control in the stretching zone, deterioration of the yarn quality, increased unevenness in strength, and is the main cause of breakage. When necessary, use a small amount of oil agent to reduce the friction between fibers and improve the processability.
Coarse yarn quality:
Carding moisture regain rate: An appropriate moisture regain rate (generally controlled at 6.5% to 7.2%) is beneficial for smooth drawing process, good fiber cohesion, less hairiness, and high strength. If it is too dry, there will be more fly fibers and more broken ends; if it is too wet, it is prone to wrap around the rubber rollers and roilers.
Coarse yarn structure: It is required that the coarse yarn has uniform yarn quality, moderate twist, and a smooth surface. Any unevenness, details, or hard points in the coarse yarn itself will directly lead to breakage of the fine yarn.
II. Equipment Status (Precision Maintenance, Consistent Standards)
The equipment status is a key factor affecting the cutting point. It is necessary to achieve the "three levels of flatness and three levels of accuracy" (rollers, spindles, and steel sheaths should be flat; spacing, stretch ratio, and twisting should be accurate).
Stretching component:
Rubber roller gasket: The surface should be smooth, round, without damage, aging or oil stains. Regular grinding and re-grinding should be carried out to ensure good grip performance and friction performance. The hardness selection should be appropriate.
Upper and lower pins: The positions are accurate, without burrs or wear, ensuring smooth operation of the rubber ring.
Lola: The rolls should be clean, without bends or wobbling, and the roll grooves should be clear without any wear. The roll bearings need to be lubricated regularly to ensure smooth operation.
Twisting and winding components:
Selection: This is the key to preventing breakage. Based on the yarn count, raw materials, spinning speed, and the condition of the steel leader (new or old), select the appropriate model and weight (number). If it is too heavy, the tension will be too high, which is prone to causing breakage. If it is too light, the air ring will be too large and collide with the inter-sheave plate, also leading to breakage and instability.
Cycle: Strictly follow the replacement cycle of the steel wire ring to prevent it from wearing out and damaging the yarn.
Spindle: It is a heart component. It must be vertical, centered, and stable. There should be no shaking or wobbling. Regularly clean the spindle, use spindle oil of the specified brand and model, and keep the oil level moderate.
Steel collar: It is a pair of friction surfaces with the steel wire ring. The steel collar track should be smooth, without wear or rust. When the steel collar reaches the end of its service life, it should be replaced promptly. A new steel collar needs to be broken in.
Wire loop:
Guide hook: It serves to guide the yarn and stabilize the air ring. It should be smooth, without any gaps or wear, and its position should be aligned with the center of the spindle.
Partition Plate: Its function is to separate adjacent air chambers to prevent them from colliding with each other. It is required to be installed at the correct position and have a smooth surface.
Cleaner: The gap should be adjusted properly. It should be able to effectively remove lint while not causing excessive scratching of the yarn.
Air ring (if used): Properly control the shape of the air ring to reduce the tension peak during the small yarn process.
III. Process Optimization (Reasonable Design, Fine-tuning Adaptation)
The process parameters should be adjusted promptly in response to changes in raw materials, temperature and humidity, and equipment conditions.
Twist design: While ensuring the strength of the yarn, appropriately increasing the twist can enhance the strength of the yarn and reduce breakage. However, excessive twist will affect production output and hand feel, so a balance point needs to be found.
Spindle speed (winding speed): The most direct and effective adjustment method. The breakage rate is directly proportional to the square or even higher powers of the spindle speed. When the breakage rate is high, appropriately reducing the spindle speed will have an immediate effect. Especially during the small yarn stage (when the tube bottom is formed), the air ring is long and the tension is high, and variable speed control can be adopted to reduce the speed when winding small yarn.
Post-zone stretching and lap distance: Reasonable post-zone stretching ratio and lap distance are beneficial for controlling the fibers, improving the yarn structure, reducing details and roughness, thereby reducing breakage.
Wire ring weight: As mentioned earlier, adjusting the wire ring size slightly according to the actual situation is an important method for the weaver and the maintenance worker to control the breakage during production.
IV. Temperature and Humidity Management (Creating a Stable Environment)
The textile industry is a "weather-dependent" sector, and temperature and humidity are of utmost importance.
Temperature: Generally maintained between 26℃ and 30℃.
Relative humidity: The relative humidity in the spinning workshop is generally controlled within 50% - 60%.
Excessive humidity: The fibers are prone to entangle the rubber rollers and roving, causing the "three-wrap" problem and resulting in breakage.
Too low humidity: more flyaway fibers, high static electricity, poor fiber adhesion, more hairiness on the yarn, strength decreases, and breakage increases.
The temperature and humidity in the workshop should be kept stable to avoid regional differences and drastic fluctuations.
V. Operation and Management (Execution is Complete, Forming a Closed Loop)
Standard Operating Procedures: The operator should perform the joint operation in a standardized and rapid manner to prevent defective joints from causing secondary breakage. Cleaning work should be carried out on time, but the methods must be correct to prevent flying debris from entering the yarn strand.
Preventive Maintenance (TPM): Establish and strictly implement the regular maintenance, cleaning, and overhaul cycles for equipment. It is not about repairing when something breaks down; instead, it involves regular maintenance, inspection, and replacement of worn-out parts.
Data tracking and analysis:
Record the breakage rate and analyze the distribution of breaks (such as which machine, which spindle position has more breaks).
Analyze the reasons for the breakage (was it due to the entanglement of debris? Or was it a lack of power? Was it a detail issue? Or was it a mechanical problem?), and address them specifically.
For the "bad ingots" that frequently break and fall off, they should be marked and given special maintenance to prevent the equipment from operating under faulty conditions.
Strengthen training: Enhance the technical skills and sense of responsibility of the guards and maintenance workers, enabling them to promptly identify and report problems.
Summary and Recommendations
Reducing the breakage rate of the spinning process does not have a "one-size-fits-all" solution; instead, a systematic and meticulous comprehensive management approach must be adopted.
Quick troubleshooting steps:
First, let's look at the raw materials and the roving: Check if there have been any changes in the quality and moisture content of the current batch of roving.
Then check the temperature and humidity: Make sure that the temperature and humidity are within the standard range and remain stable.
Then focus on the wire rope ring: This is the component that is most frequently adjusted. Ask the dockworker about the pattern of breakage. If there are large-scale breaks accompanied by an increase in frayed edges, it is likely that the wire rope ring selection was incorrect or it has reached the replacement cycle.
Check the equipment status again: If the breakage rate of individual spindles is high, it is likely that there are problems with the spindles, guide hooks, steel collars, etc.
Finally, consider the process: If everything is normal as mentioned above, then consider whether the vehicle speed is too high or the process design is unreasonable.
By implementing comprehensive control throughout the entire process from raw materials to finished products, establishing standards, strictly enforcing them, and continuously improving, the breakage rate of the spinning machine can definitely be kept at an ideal level.