Analysis of the causes of poor forming of 14 types of package yarns 1. Overlapping packages (1) What is an overlapping package? Overlapping winding means that the yarns are at or near the same position, falling together and winding to form a strip winding. (2) The consequences of harmful overlapping bobbins on the unwinding process of subsequent processes: A. High-speed unwinding breakage due to decoupling! B. High-speed unwinding and breakage (adhesion) due to involvement (3) The usual anti-overlap methods of self-winding machines are as follows: Method 1. Usually the anti-overlap mechanism disperses possible overlap by reducing or increasing the rotation speed of the groove drum. Winding, (the opening and closing time of the grooved drum motor is different from each other) thereby causing the grooved drum and the bobbin to slip and reduce yarn overlap. Common models include Murata 7-2, 7-5, 7-7, 21C, Schlafhorst 138, 238, 338, Lorian, Qingdao SMARO and other models! Method 2: This anti-overlapping mechanism uses a slight left-right swing of the bobbin cradle, that is, the pressure change range of the contact surface between the bobbin and the grooved cylinder, which causes the grooved cylinder and the bobbin to slip and reduce yarn overlap. Common models include early Savio and Qingdao ESPERO. Method 3: This anti-stacking mechanism realizes the anti-stacking of the bobbin by changing the number of groove turns of the groove barrel through program control. When using ordinary grooved cylinders, the phenomenon of bobbin overlap is most likely to occur when the diameter of the bobbin is close to a multiple of the diameter of the grooved cylinder. When using grooved cylinders with different number of groove turns, the diameter of the bobbin overlap will be different to a certain extent. The grooved drum takes advantage of the different diameters of the drums when overlapping bands occur, effectively avoiding the overlapping bands. Usually, the diameter of the overlapping band is much smaller when using a 2-turn trough barrel than when using a 2.5-turn trough barrel. This is common. The model is Murata 21C. The bobbin produced by using the changing grooved drum has obvious traces of interfering interference in the changing ring. (4) Causes and solutions of overlapping bobbins. When the diameter of the grooved drum and the diameter of the bobbin form an integer ratio, overlapping winding is most likely to occur. If the automatic winding machine is enabled with the above prevention When stacking the mechanism, the probability of overlapping bobbins under normal circumstances is low. When the bobbin winding conditions are abnormal and the bobbins are overlapping, the usual processing methods are: (1. Optimize the acceleration and deceleration of the grooved bobbin) Ratio. (Anti-stack dry winding setting); 2. Set to reduce the contact pressure between the bobbin and the trough (increase the balance air pressure of the cradle, the balance air pressure of the cradle is inversely proportional to the contact pressure between the bobbin and the trough); 3. The cradle or chuck is not operating properly; 4. Over-large diameter packages may cause overlapping packages. 5. The moisture in the spun yarn tubes or the humidity of the winding production environment is too high; 6. Slightly increasing the winding tension will be helpful in reducing overlap. Minimal effect. 2. Chrysanthemum core bobbin. (1) What is a chrysanthemum core bobbin? In the area where the package head is close to the bobbin, the yarn layer is squeezed to cause a “daisy core”. The reason is that the outer yarn is relatively small Caused by large pressure acting on the inner yarn. (2) Several factors that produce chrysanthemum core bobbins. Varieties with softer yarn characteristics, varieties with thicker yarn counts, high moisture regain of yarns, etc. When the linear elasticity is high, rotor spinning, wool-proof yarn, etc. are more likely to produce chrysanthemum cores (3) Causes and solutions of chrysanthemum core bobbins A. When the tension is too small and the contact pressure is inappropriate, it is easy to occur. The above parameters need to be optimized. ; B. Serious bobbin eccentricity is easy to occur, replace the qualified bobbin; C. The contact surface between the bobbin and the grooved cylinder is poor, please correct the relative position between the small end of the bobbin and the grooved cylinder. (The contact surface between the bobbin and the grooved cylinder is on the left If there is a certain gap between the sides, the core of the package will be softer after being rolled); D. Excessive increment during winding will also lead to chrysanthemum core packages. 3. Raised edge bobbin (1) What is a convex edge bobbin? The cause of side bobbins is that as the winding diameter of the bobbin increases, the corresponding contact pressure between the bobbin and the grooved bobbin increases, and the winding density of the yarn also increases, causing the inner yarn of the bobbin to be compressed and squeezed from the sides. Protruding. (2) Causes and solutions of convex bobbins A. Thick yarns, double-ply yarns, elastic yarns, and bulked yarns are prone to such poor forming phenomena; B. For the above elastic yarns, excessive tension If the contact pressure is too large, convex bobbins are prone to occur; C. You can try to use the tension and contact pressure gradually reducing device to solve the problem. 4. Random yarn layer bobbin (1) The formation and harm of the random yarn layer during the high-speed winding process Slight slippage occurs between yarn layers, resulting in the occurrence of random yarn layers. This slight slippage between yarn layers sometimes manifests itself as yarn adhesion during the high-speed unwinding process of the package yarn, resulting in breakage. (2) Causes and solutions to the disordered yarn layer A. Excessive suction static pressure may cause disordered yarn layer bobbins. Properly reduce the static pressure and install it on machines without suction motor inverters! B. Blowing When knotting, the big suction nozzle touches the bobbin. When the diameter of the small head is 120 mm, adjust the distance between the big nozzle and the bobbin to 5-6 mm. C. Repeat the knotting action several times in succession. Adjust the twisting quality and make a good order. Spindle maintenance work! D. The contact pressure of the bobbin is too low. Appropriately increase the package contact pressure (note: the balance air pressure is inversely proportional to the package contact pressure) E. The overlapping yarn layer is loose. Adjust the ON and OFF time ratio F of the anti-overlapping motor. This may occur when the yarn is slippery, the moisture regain is small, or when the distance between the large suction nozzle and the bobbin is too small during knotting. Appropriately increase the package contact pressure and air humidity (65%-70%), and optimize the parallel distance and negative pressure between the large nozzle and the package! G. The tension unexpectedly decreases or disappears at a certain moment in a short period of time. Repair, clean and clean the tension system. Strengthen on-site management! H. The chuck bearing of the bobbin cradle is running poorly. Repair and clean the bobbin cradle chuck! ��� I. Yarns with high friction coefficients, brittle fibers and yarns that generate high static electricity accumulation are prone to problems. Optimize the vehicle speed, tension and cradle pressure, and appropriately increase the air humidity of the production environment! J. Excessively high bobbin winding speed. Reduce the winding speed appropriately! 5. Cross-side (climbing head) bobbin (1) What is cross-side (climbing head) bobbin? The yarn is thrown out from the left or right end of the bobbin. See Figure (2) Causes and solutions of side-crossing (top-climbing) bobbins A. The bobbin contact pressure is too small, causing excessive slippage between the grooved drum and the package. Appropriately increase the bobbin contact pressure
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