March, 2024- Cut-to-length and multi-blanking lines convert ferrous and nonferrous flat-rolled metal coils into sheets and precision dimension blanks. Generally, the lines are custom designed and built to meet customers’ raw material specifications and production requirements, so every line includes unique elements that contribute to the desired results and productivity.
Schiller Park, Illinois-based Braner’s new multi-blanking cut-to-length lines can process coils up to 40 tons—hot-rolled carbon steel, galvanized, coated, painted, stainless steel and aluminum up to 1/4-inch thick. These high-speed lines are designed to handle large volumes quickly and efficiently.
Braner’s 72-in.-wide by ¼-inch-thick, six-cut-mult multi-blanking line.
The five-high cassette leveler processing diamond plate material.
PRECISION LEVELING
The multi-blanking line features a cassette leveler with multiple work roll cassette cartridges to process material ranging in thickness from 0.018 up to ¼ inch thick. Interchangeable work roll cassettes increase the material thick-ness range. The machine can be equipped with one, two or more leveler cassettes in four-, five-or six-high work roll arrangements. Typical cassette work sizes range from 1.25-inch to 3.5- inch diameters. Interchangeable work roll cassette levelers are quickly replaced in and out of the machine in a matter of minutes onto a cassette storage and transfer shuttle.
DEAD FLAT
The entry work rolls are adjustable to correct strip shape edge wave, center buckle and crossbow defects. Braner’s hydraulic levelers have the additional ability to bend the exit work rolls independent of the entry ones to give the operator more control to achieve dead-flat material. Each adjusting cylinder is precision controlled by a linear transducer for exact roll positioning.
A touchscreen interface through a programmable controller automatically positions leveler setups for a given coil thickness, width, yield strength and penetration from light to heavy. Entry and exit work roll gaps are automatically adjusted. Work roll bending to eliminate shape defects is displayed via bar graphs on the operator setup screen. The operator can fine tune the leveler position settings and commit those to a memory table.
The leveler work rolls are driven through a proprietary TorqueMaster leveler drive. Unlike traditional roller levelers that are driven by a single motor and multiple output distribution gearbox, the TorqueMaster levelers drive each roll independently through dedicated motors and gearboxes, providing flatness and memory stabilization through their ability to plunge level work rolls deeper.
Deeper penetration allows the leveler to remove trapped stresses necessary to produce memory-free, flat sheets. High-strength materials require a great deal of torque to be transmitted to the work rolls. Traditional levelers that are driven by one, sometimes two motors via a multiple distribution gearbox with output shafts are problematic because all the work rolls are all geared together. There is no allowance for speed mismatch between the rolls, resulting in huge wind-up stresses in the gearbox and universal shafts.
Levelers with ordinary drive trains can experience gearbox and drive train failures; however, TorqueMaster levelers overcome these problems by driving each work roll individually.
An advantage of cassette levelers is ease of maintenance. Cassettes can be removed from the line for cleaning, inspection and work roll changes while running the line with the other cassette. The top set of rolls can be pulled off and opened for easy access. A cassette turner to flip open the upper set of rolls aids the process. Work rolls can be replaced in a day, unlike the multi-day job required to service traditional fixed-in-place levelers.
The slitter heads can be tooled off line and interchanged in a matter of minutes.
ADDING VALUE
Top/bottom side PVC protective film and paper can be applied with an applicator. An expanding mandrel air shaft coupled to a pneumatic tension brake applies protective film or paper interleaving. An electrostatic charge bar secures paper to the material processed. The applicators can be positioned in and out of line for easier roll changes.
Edge trimming and multi-blanking is accomplished with two or more quick-change packed arbor slitter heads. The slitter heads can be tooled off line and interchanged in a matter of minutes. Packed arbor slitters can hold much tighter width tolerances and hold material flat as it is cut. When processing full-width sheets, the slitter heads are positioned off line so material doesn’t need to pass through the unused slitter heads.
A precision non-marking servo roll feed positions material into the highspeed shear. Full-width large diameter rolls are specially coated to suit the application, ensure grip and length accuracy. The clamping pressure is adjustable and the rolls are driven by an AC motor and anti-backlash gear train to hold precise length tolerances. Quick-change separator tooling bars and motorized squaring guides are positioned coming out of the looping pit and into the feeder on wide centers to ensure precise diagonal tolerances.
A hydraulic shear with an adjustable blade clearance cuts material to accurate lengths. Traditional mechanical shears using a clutch-andbrake mechanism have many moving parts and bushings that are prone to wear, high shock and dynamic loading. Braner’s shear employs a hydraulic system capable of cycling up to 60 cuts per minute. The shear is quieter than those of other makers, and doesn’t generate the dynamic floor and shock loading of comparable mechanical shears. The clearance between the upper and lower knives is adjustable for the thickness range processed to ensure precise cut edge quality.
LAST STEPS
Once sheared, material is fed onto a belt conveyor, where it can be inspected for flatness and measured without having to pull sheets and blanks out of line. A pop-open feature allows operators to reject material and cut scrap.
The conveyor feeds material into the stacker. When processing fullwidth sheets, rollers support sheets entering the stacker and are opened to drop sheets into the stacker. Blanks are guided in tapered squaring skirts to process six or more sheets simultaneously. An adjustable-speed air blower is used to support and cushion stacked material.
A powered end stop with a tamping feature ensures that stacks that come out looking like blocks. Squaring and side skirt adjustments are powered for ease of setup. A scissors lift end or side discharge conveyor automatically lowers to remove finished packages from the machine.
Braner USA Inc., 847/671-6210, braner.com.
