A cut-to-length (CTL) uncoil and level a coil of material, cuts it into sheets of precise lengths and stacks those sheets into a bundle. Functions can include, but not be limited to, coil stocking and coil loading, uncoiling and coil opening, straightening of the leading edge of the coil, edge trimming, scrap cutting, and sheet stacking. In-line equipment used in a system can vary according to the width, thickness and incoming coil weight and may include coil storage, uncoiler and coil loading, leveler, flattener, roll feeds, shears, sheet stacker and related tooling and accessories.
A cut-to-length line processes metal coil rolls by uncoiling, straightening, shearing to length and stacking of sheet metal blanks. These lines provide automation that ensures accurate feeding, flattening & shearing for a variety of industries.
A CTL or a Blanking Line will take a master coil of flat-rolled steel from the integrated or mini-mill and unroll, flatten and cut to length sections to a precise length and stack the sheets into a bundle. Equipment will vary according to the width, thickness and incoming coil weight. Depending on the final end product to be utilized from the cut sheet, flatness may be a critical point and use of a double leveler, skin pass or stretcher leveler may be employed in the process.
Stop-Go Lines are less expensive than continuous CTL’s. The strip is fed through the line quickly and then deaccelerated and comes to a complete stop. The stationary shear fires and a sheet or blank is produced to a predetermined length. Tight-line configurations can be a good choice if the footprint inside your plant is limited because they usually are shorter than free-loop designs. The foundation costs are lower because a looping pit isn’t required, and the thickness capacity of tight-line machines is virtually unlimited, making them ideal for heavy-gauge applications. Tight-line machines with stationary shears have the lowest cost of any cut-to-length line but have the lowest productivity as well. In addition, tight-line machines may damage thinner materials because visible roll marks can appear where material stops in the leveler. A flying shear can be installed to increase production especially in the case of heavy gauge. The flying shear must be synchronized perfectly with the speed and location of the moving strip. Synchronization can be achieved, but the cost is usually substantial
In this variant of a CTL, the strip is fed out of the master coil and through the flattener and or leveler. The strip is now fed at a constant rate into a looping pit of a desired depth according to the thickness and speed of cutting to length. At the other end of the loop, a separate servo feeder measures and feeds the material to the shear. The shear can be stationary or flying type. The continuous CTL is preferred when lighter gauges are cut to length generally less than 3mm.