Pulling and straightening roller: a flat dual effect carrier for metal strip processing

2025-09-05 11:19:46

In the deep processing of metal strips (such as cold-rolled strip, stainless steel strip, aluminum strip), the raw materials often generate internal stress due to uneven rolling and cooling, accompanied by deformation problems such as wave shape, side bending, and ladle bending, which directly affect the accuracy of subsequent stamping, welding, coating and other processes. As the core component of the straightening machine, the straightening roller is different from the roller body with a single straightening function. Through the synergistic effect of "stretching+straightening", it can eliminate residual stress inside the strip and repair surface flatness, achieving the processing standard of "uniform stress and flat plate shape" for the strip. It can be called the "dual effect carrier of stress relief and flatness" in metal strip processing.

The core value of the Straightening Roller comes from its structural design and working logic that adapts to the "stretching straightening" composite process. From the overall structure, the straightening roller system consists of an inlet tension roller, a straightening roller group, an outlet tension roller, and a support mechanism. The division of labor for each part is clear: the inlet tension roller is driven by a motor to provide stable tension, stretch the strip to near the yield limit, and break the original stress balance; The central correction roller group is the core working unit, which adopts multiple sets of staggered roller bodies (usually 6-20 sets) arranged vertically. The roller spacing is adjusted according to the thickness of the strip (thin strip spacing is small, and there are many roller groups). When the strip passes through the correction roller group under tension, the roller body applies continuous bending force to it, causing plastic deformation in various parts of the strip and gradually eliminating stress unevenness; The export tension roller maintains stable tension for subsequent transportation, avoiding rebound of the strip after correction.

The application field of straightening rollers focuses on the fine processing of metal strips, and the application characteristics vary significantly in different industries. In the automotive industry, for the straightening treatment of cold-rolled steel plates and hot formed steel used in car bodies, the flatness error of the strip needs to be controlled within 0.05mm/m, while eliminating internal stress to ensure that it is not easy to crack or rebound during subsequent stamping and forming, and to ensure the dimensional accuracy of components such as doors and engine covers; In the home appliance industry, stainless steel strip straightening is suitable for refrigerator side panels and washing machine inner tubes. The flexible roller surface design protects the surface glossiness of the strip, avoiding scratches that affect its appearance, while ensuring that the strip is flat for subsequent welding and coating; In the electronics industry, aluminum and copper strips used for lithium battery lugs require high-precision micro convex roller surfaces to ensure uniform thickness in the width direction of the strip (deviation ≤ 0.005mm), while eliminating stress and preventing deformation of the lugs during subsequent cutting and welding; In the building materials industry, for the straightening of color coated plates and aluminum buckle plates, it is necessary to balance flatness and surface protection, avoid damaging the surface coating of the strips during the straightening process, and ensure seamless splicing of the subsequent processed plates; In the metallurgical industry, it is used for pre production straightening of strip steel and aluminum coils. Through the combination process of "coarse straightening+fine straightening", the strip steel meets the national standard requirements for plate shape and stress indicators, meeting the processing needs of downstream customers.

The use and maintenance of straightening rollers should revolve around "maintaining accuracy" and "extending lifespan", with three key points to focus on. One is the matching of process parameters, adjusting the tension and correction roll pressure according to the material and thickness of the strip - soft strips (such as aluminum strips) need to control the tension at 30% -50% of the material yield strength to avoid excessive stretching and thinning of the strip; Hard strips (such as stainless steel strips) can be appropriately increased in tension to 50% -70% to ensure sufficient stress relief; The second is daily inspection and cleaning. Before each start-up, check whether there are scratches, pits, or impurities accumulated on the roller surface. If impurities are found, use a soft cloth dipped in neutral cleaning agent to wipe them off to avoid impurities pressing into the surface of the strip; Regularly measure the convexity of the roller surface. If the convexity wear exceeds 0.05mm, it should be promptly ground and repaired to prevent the occurrence of "medium waves" or "edge waves" in the strip; The third is lubrication and anti-corrosion maintenance. The roller neck bearings need to be regularly lubricated with high-temperature grease (such as lithium based grease) to ensure flexible rotation and reduce friction losses; For humid and corrosive environments (such as galvanized strip processing), anti rust oil should be applied to the non working surface of the roller body to avoid rusting of the roller neck and affecting the rotation accuracy; When idle for a long time, the straightening roller should be disassembled and wrapped in rust proof paper, and placed in a dry and ventilated environment to avoid oxidation or deformation of the roller surface.

With the development of metal strip towards "thinning, high precision, and high hardness", the technology of straightening rollers is also constantly upgrading. Nowadays, some straightening equipment uses servo motors to drive straightening rollers, achieving precise closed-loop control of tension and roller speed, and adapting to dynamic adjustment of different material strips; There is also a product integrated roller surface wear monitoring function, which detects real-time changes in roller surface convexity through sensors and automatically alerts maintenance needs; In special fields such as ultra-thin metal foil straightening, ceramic coated straightening rollers are used, with a surface hardness of HV 1200 or above, further improving wear resistance and smoothness, which can meet the straightening needs of micrometer sized strips. As a "dual effect carrier" for metal strip processing, the straightening roller will continue to provide reliable support for deep processing of strips in various industries with stable stress relief ability and high-precision leveling effect.