Many multi-blanking slitters are installed after the looping pit, slitting the strip in a start-stop cycle synchronized with the strip feeder cycle. By comparison, the J&F slitter is installed before the looping pit, slitting the strip at a constant line speed synchronized with the Cassette Leveler. By slitting at a uniform non-stop line speed, J&F is able to avoid problems associated with knife slippage and produce uniform high-quality close-tolerance slit edges on all multi-blanks.

To minimize slitter set-up time, the J&F Turret Head slitter employs a custom designed precision shimless tooling package specifically designed for side trimming and the production of multi-blanks 5" and wider. The Turret Head slitter, with the custom tooling package, is able to produce precise ±.002" slit width tolerances while also allowing multi-blank set-ups to be accomplished in 1/4 to 1/3 the time normally required to complete a typical coil slitter set-up. Depending upon the number of cuts and widths, coil slitter set-ups can take as long as 45 minutes to complete. But with the quick loading and lightweight tooling design of the Turret slitter plus the advantage of the custom multi-blank tooling, J&F can finish a typical multi-blank set-up in about 15 minutes. Special spacers that are 53% lighter than conventional spacers are a key element in the custom-tooling package, and the lightweight spacer design makes extra-wide spacers feasible. Employing extra-wide spacers to generate 2 to 5 multi-blank strips dramatically reduces spacer "piece-count" and set-up time is reduced. For example, a shimless coil slitter set-up for eleven 3.125" and eight 2.875" x .030" strips would need 283 spacers and about 45 minutes to set-up. With J&F’s custom tooling package, a multi-blanking set-up for one 30.000" and one 29.500" x .030" blank would need only 43 spacers. 43 spacers versus 283, or 1/6th the number of pieces. Since set-up time is directly proportional to the number of pieces that have to be loaded and removed, it makes sense that less pieces means less set-up time. The J&F Steel Turret Head slitter equipped with the multi-blank tooling package can be re-tooled for most orders in 15 minutes. Since it takes more than 15 minutes to process any size multi-blanking run, the slitter set-up can be finished before it is needed. More importantly, J&F is able to re-tool for the next order while the line is running, so no production time is lost.

Precision Electronic Servo Feed: The J&F Multi-Blanking Line employs a Precision Servo Feed to feed and measure strips for cut-off. The Servo Feed uses high-traction non-marking feed rolls driven by a precision electronic AC vector servo system to feed and measure the strips. The feed rolls are full-width with back-up rolls that eliminate feed roll deflection. A state-of-the-art motion control system capable of producing consistent sheet and blank length tolerances of ±.005" is employed for feed length measurement.

The electronic motion control receives feed roll position data from an electronic encoder, and the position information is instantly transformed into accelerate, decelerate, and full stop commands based upon the feed length. The motion-control system automatically computes the ideal production speed based upon the part length entered into the operator data panel. An adjustable acceleration/deceleration control is provided to compensate for various material surface conditions.