RK DPS-40 Duplex Slitter – Roll to Roll Duplex Slitter Rewinder Machine

A duplex slitter is a slitting rewinding machine with two rewind shafts, one above the other. Alternate slit rolls go to the upper and lower shafts, so the blades can be set close together without the neighbouring rolls rubbing against each other while they wind. That is what makes it suitable for cutting a wide parent roll into many narrow rolls in a single pass.

The DPS-40 takes a jumbo roll of up to 1050 mm width on a 3 inch air shaft unwinding unit with an electronic web guide and an automatic tension controller, passes the web through a slitting section with rotary and normal (razor type) shear blades and winds the slit rolls on the up and down rewinding unit. The main drive is a 7.5 HP three-phase AC variable speed motor, and the machine footprint is roughly 7.5 ft long, 6.5 ft wide and 4 ft high.

1050 mm Paper Feeding Width

The unwinding side accepts a parent roll of up to 1050 mm width, which covers the standard jumbo widths that label stock, thermal paper and other paper rolls are supplied in.

Air Shaft Unwinding Unit With Web Guide and Tension Control

The unwind is on a 3 inch air shaft and accepts a roll of up to 600 mm diameter. An electronic web guide keeps the edge of the paper in the same place as the roll unwinds, and an automatic electronic tension controller with load cell and pneumatic brake holds the tension steady, so the slit widths stay consistent from the start of the roll to the end.

Up and Down Type Rewinding

Slit rolls are wound on two rewind positions, one above and one below, on 3 inch air shafts, up to 600 mm diameter each depending on the slitting width. Splitting the rolls between the two shafts keeps the narrow rolls apart and lets the operator set closely spaced cuts.

Rotary and Normal Shear Blade Slitting

The slitting section has rotary and normal shear blades, 10 pieces, which are simple to reposition when the slit width changes and are easy for an operator to replace on the shop floor. The free rolls are Teflon coated for non-sticky material and the rubber roll is silicone coated.

Electronic Meter Counter With Auto Stop

The counter measures the length wound and stops the machine automatically at the set length. Every finished roll then carries the same running metres, which is what customers of a stock lot converter ask for.

Air Blower for Waste Trimming

The edge trim is carried away by an air blower, so the operator does not have to handle the waste strip by hand during the run.

Variable Speed Main Drive

A 7.5 HP three-phase AC motor with variable speed control and a Schneider VFD lets the operator run a delicate material slowly and a sturdy paper at the full 100 m/min.

The operator loads the jumbo roll on the unwind shaft and threads the web through the web guide, over the slitting section and on to the two rewind shafts. The blades are positioned at the required slit widths and the cores are placed on the upper and lower rewind shafts in alternating order, so that roll one goes up, roll two goes down, roll three goes up and so on. The set length is entered on the meter counter.

When the machine starts, the variable speed drive brings the web up to running speed while the web guide holds the paper edge steady. The blades slit the web into strips, the strips wind on their respective shafts and the edge trim is pulled away by the air blower. When the counter reaches the set metres, the machine stops on its own. The operator cuts the web, removes the finished rolls from both shafts, loads fresh cores and starts the next set.

• Jumbo roll conversion – cutting 1050 mm parent rolls of label stock into press-width rolls for flexo and letterpress label machines.
• Stock lot slitting – reworking odd or leftover rolls into saleable widths.
• Thermal paper rolls – slitting thermal paper jumbo rolls into narrower reels before POS roll production.
• Paper reel slitting – general paper roll slitting for packaging and printing houses.
• Self-adhesive label stock – producing multiple narrow rolls of self-adhesive material in one pass.

The DPS-40 is built for paper based rolls: self-adhesive label stock, thermal paper, plain and coated papers and similar materials supplied in jumbo or stock lot form. Rotary and normal shear blade slitting suits these materials well. If you plan to slit films or heavier boards, tell RK what you run so the blade set, tension and rewind arrangement can be checked against your material before the machine is offered.

• RK Drum Slitterthe other jumbo and stock lot slitting machine in the RK range, built around a drum rewind.
• Label Slitting With Turret Rewindingnarrow web label slitter with turret rewind for finished label rolls.
• Label Slitting With Up and Down Rewindinghigh speed narrow web slitter rewinder for printed labels.
• POS Roll Slitting Machinethermal paper slitting and rewinding for POS rolls.

RK Label Printing Machinery Pvt. Ltd. has built label printing and converting machinery in Ahmedabad, Gujarat since 1995. The company runs three manufacturing units and has supplied machines to customers in 23+ countries. Because RK also builds the flexo presses, die cutters and label slitters that the slit rolls will run on, the duplex slitter is designed with those downstream machines in mind, and the customer gets the whole converting line, and its service, from one manufacturer.

• Parent roll width: the DPS-40 takes up to 1050 mm. Measure your widest jumbo roll before you decide.
• Parent roll diameter: the unwind accepts up to 600 mm diameter. Larger rolls will need to be discussed with RK.
• Finished roll diameter: each rewind position takes up to 600 mm. If your customers want bigger finished rolls, ask about the Drum Slitter.
• Number of cuts per pass: many narrow rolls from one wide web point to a duplex design, because the up and down rewind keeps close-set rolls apart.
• Material: paper based rolls are the standard duty. Share film or board requirements in advance.
• Length accuracy: if every roll must carry the same metres, the meter counter with auto stop does that for you.

The price of the RK DPS-40 depends on the configuration supplied, such as blade sets, shaft options and any changes to the unwind or rewind arrangement for your rolls. RK quotes ex-works Ahmedabad, with GST at 18% applicable. Engineer travel and stay for installation and operator training at your site are borne by the customer. Send RK your parent roll widths and diameters, the finished widths you need and the material you run, and the team will confirm the right build and quote against it.