Technical and management solutions for the problem of horizontal stripes produced by circular knitting machines

one. 1. The mechanical part is inaccurate. Due to the low precision of the equipment or the aging of the mechanical equipment, the single-piece leakage and flatness of the syringe, as well as the synchronization data exceeding the allowable range, will all cause changes and fluctuations in the yarn feeding tension, eventually leading to the formation of transverse paths in the coil size. Such transverse paths usually disappear after adjusting the mechanical data. 2. Problems with the yarn feeding tray and the wire feeder In some manufacturers with a large number of flying gears and poor dust removal systems, if the sliding blocks in the yarn feeding tray are not cleaned for a long time, the accumulated flying gears will cause the rubber sleeves of the sliding blocks to age, resulting in abnormal belt response, abnormal speed, cross-path caused by the speed of yarn feeding, accumulation of flying sparks in the yarn feeder, and the upper and lower reverse gears not being in the transmission position. Eventually, when the machine is started, the yarn is in a negative state, causing cross-path. 3 debugging problems When adjusting the machine, the triangular depths of the upper and lower presser pins are not uniform, resulting in different sizes of the fabric surface coils and creating transverse paths. Such issues usually follow a certain pattern. Since the depth of the upper triangular presser pin is rather difficult to observe with the naked eye, when adjusting the machine, we first set the lower presser pin to a presser pin depth position, and then adjust the upper presser pin. At this point, the tension of the yarn is used as the standard During this process, we will encounter a common phenomenon: for ribbed fabric, the size of the lane in the middle of the two circles perpendicular to the straight line on the fabric surface will sometimes change and sometimes decrease. The reason for this is that the upper pressing needle is not pressed evenly. This phenomenon also occurs in cotton and wool, and the fabric surface will look very ugly. In addition, the uneven distribution of the upper and lower triangular seats can also lead to this phenomenon. The concept of this equal division is that the upper and lower parts of the circumference are not evenly divided, so that the upper and lower needle pressing and straightening points are inconsistent during fabric formation. This problem is also difficult to be detected by the naked eye. 4. Raw material issue, raw material issue is relatively common, and the resulting horizontal path forms include yellow and white horizontal paths. Irregular cloud spot transverse paths, this type of transverse path can generally be solved after changing the yarn, but some are hidden transverse paths, which are the most troublesome. Poor yarn quality, uneven twist, and mixed yarn count can all cause such problems. The transverse stripes of spandex fabric are also a common issue. Some lower-quality spandex fabrics have more problems. For instance, excessive stickiness and fluffiness. 5. Color difference issue: Sometimes we encounter such a situation where there are no transverse paths on the rough blank, but when the smooth blank comes out, it is all transverse paths. At this point, the weaver would talk about the problem of dyeing and bleaching, and the dyeing and bleaching would talk about the problem of weaving. I once heard a friend tell me this: This is the color difference caused by the poor color absorption of the raw materials. It’s fine to dye light colors or bleach them. It seems to make some sense, but whether it’s really the case or not, I have no way to verify. Here, I’d like to invite a friend who is in the dyeing and finishing industry to share their thoughts on this topic. 6. Issues with the yarn guide mechanism of the yarn frame: This type of problem occurs in the spinning ring machine, especially when the F-number of the synthetic fiber filament is relatively high. Generally, it is caused by the yarn guide mechanism pulling or tightening the transverse path. Such transverse paths are not obvious, so some manufacturers’ commissioning technicians will check by feeling the tension between the floor-standing yarn frame or the yarn feeder. 7. The problem of the shutdown cross path is generally due to the clearance between the main shaft driving gear and the large disk gear, as well as the fit clearance between the large disk base and the large gear. The thicker the layout, the more obvious the shutdown cross path will be. For such cross path debugging, at most, it can be reduced. It is unlikely to completely eliminate it because it has been determined at the factory. Two The technology and management for solving the problem of horizontal stripes in knitting yarns will significantly reduce the probability of such stripes occurring. No matter under what circumstances knitting yarns produce horizontal stripes, it will cause considerable economic losses to knitting yarn and knitted fabric manufacturers. Whether knitting yarns will produce horizontal stripes in the subsequent dyeing process of knitted fabrics can only be known after dyeing. The appearance of horizontal stripes on knitted fabrics is due to problems in cotton mills as well as those in knitting mills and dyeing and finishing mills. Generally, the classification of horizontal stripes on knitted fabrics follows the following empirical rules: ① For those with regular patterns and obvious horizontal stripe shadows in cotton mills, it is usually caused by uneven twist of certain single yarns, wrong numbers, excessive weight deviations, or the mixing of single or multiple cotton yarns. ② Regular horizontal stripes produced in knitting factories are usually caused by uneven tension of certain needle holes on the knitting machine or by the factory’s use of mixed, wrong numbers or wrong batches of cotton yarn. ③ The horizontal stripes on knitted fabrics produced by dyeing and finishing factories are generally characterized by light color or no regularity at all. The main reasons for such horizontal stripes are that the knitted fabrics are washed in the dyeing tank for too long, or the knitted fabrics wrinkle in the dyeing tank, preventing the dyeing solution from penetrating, resulting in a large difference in the concentration of the dyeing solution between layers. Poor dyeing water quality can also cause dyeing horizontal stripes on knitted fabrics. The reasons for the irregular horizontal stripes are as follows: uneven blending of cotton, irregular replacement of raw cotton, large differences in the maturity of cotton, uneven mixing of cotton stripes, long and thick cotton yarn with many details, insufficient dyeing pressure, uneven concentration of dyeing liquid, insufficient temperature of dyeing steam, unclean dyeing VAT, and too long boiling time of cotton fabric in the dyeing VAT. ⑤ The causes of regular horizontal stripes: There are both factors related to the cotton mill and the knitting factory. The causes related to the cotton mill include uneven twist, misalignment and wrong batching, uneven blending of cotton, and uneven cotton batching. The reasons for the knitting factory include uneven tension and misalignment. Technical measures to solve the problem of horizontal stripes in knitting yarns include: stabilizing the quality of blended cotton, and it is best to transfer the blended cotton one batch at a time. Stabilize the replacement ratio and timing of cotton; Reduce the twist difference between spindles, control the uneven weight and weight deviation of carded, combed and combined strands, prevent the mixing of cotton yarns, and prevent the occurrence of long coarse knots and long details. Management measures include: formulating quality control standards for blended cotton and conducting package inspection, implementing operation management for defect-free spinning, strengthening the maintenance and care management of equipment, and strictly blocking the dead links that cause miscounting and misgrading in the spinning factory (such as wrong tubes, mixed tubes, and wrong tube colors, etc.)