Common Problems in Circular Knitting Machine Production

Circular knitting machines are crucial in the textile industry, enabling the efficient production of knitted fabrics. However, these machines can encounter several issues that affect the quality and consistency of the output. Below are detailed descriptions of common problems encountered in circular knitting machines, along with their potential causes.

Holes in the Fabric

Holes are a frequent issue in circular knitting and can be caused by several factors. Poor quality yarn, especially if too dry, or excessively dense ring density can lead to breaks and holes. Incorrect positioning of the feeding nozzle can cause improper yarn feeding, leading to uneven tension and holes in the fabric. Loops that are too long result in thin fabric, which is more prone to holes. Excessive weaving or winding tension can stretch the yarn too much, making it susceptible to breaking and forming holes. Ensuring high-quality yarn, appropriate ring density, correct nozzle positioning, and proper tension settings are crucial to avoid these issues.

Missing Needles

Missing needles disrupt the knitting process and can be caused by the incorrect positioning of the feeding nozzle. If the nozzle is not properly aligned, it may fail to deliver the yarn accurately to the needles, leading to missed stitches. Regular checks and adjustments of the nozzle position are necessary to ensure proper yarn feeding.

Loop Setting Phenomenon

The loop setting phenomenon occurs when loops do not form correctly. This can be due to low yarn tension, causing the loops to be too long and irregular, resulting in uneven fabric. Incorrect threading through the feeding nozzle can disrupt the yarn flow, leading to improper loop formation. Low winding tension can also result in loose loops that do not set correctly. Ensuring consistent yarn tension, correct threading techniques, and proper winding tension are essential for uniform loop formation.

Needle Tongue Damage

Damage to the needle tongue can significantly affect fabric quality. High fabric density can place excessive stress on the needle tongue, leading to damage. Pre-existing damage to the needle tongue can worsen over time, affecting the knitting process. If the settling plate is not fully withdrawn, it can obstruct the removal of loops, causing damage to the needle tongue. An improperly positioned feeding nozzle can cause additional stress on the needle tongue. Regular inspections, replacements of damaged needle tongues, and ensuring the correct position of the settling plate and feeding nozzle are crucial for smooth operation.

Firing Pin Heel Issues

Issues with the firing pin heel can arise from several factors. Lack of or improper use of oil can increase friction and wear, leading to firing pin heel issues. Damaged barrels, dials, or triangles can affect the firing pin heel, and inadequate cleaning of braiding components can cause them to slip. High-speed operation or high fabric density can strain the firing pin heel, and using poor quality yarn or yarn with unsuitable needle spacing can exacerbate these problems. Regular maintenance, proper lubrication, and using high-quality, compatible yarn are essential to prevent these issues.

Sedimentation Sheet Damage

Damage to the sedimentation sheet can result from insufficient lubrication, improper use of oil, and inadequate cleaning of the sinker triangle seat. Contact between the feed nozzle or fuel nozzle and the sinker can cause damage, and an incorrect gap between the sinker and the sinker triangle can also lead to issues. Regular cleaning and maintenance, proper lubrication, and ensuring the correct gap of 0.1-0.2mm between the sinker and the sinker triangle are necessary to maintain optimal performance.

Cross Thinning

Cross thinning involves ensuring consistency in several factors. The yarn count and low elastic yarn should be from the same batch, and the yarn count tension should be uniform. The correct setting of the delivery wheel file helps prevent cross thinning, and the settling sheet must be correctly positioned.

Hard Way Issues

Hard way issues require checking several components. Ensuring that the needle groove and settler groove are not too tight or coated with oil is important for smooth operation. Additionally, checking for damage to the knitting needle and settler helps prevent hard way issues. Regular inspections and maintenance of these components are necessary to ensure smooth operation and high-quality fabric production.

Conclusion

By understanding these common problems and their causes, operators can take preventive measures to maintain the efficient operation of circular knitting machines. Regular maintenance, proper alignment, and the use of high-quality materials are essential for optimal performance and high-quality fabric production.