The quality of the finished rolls that you produce is directly related to the machine(s) you're using. Not only do you want perfectly wound rolls, but you also need to produce them efficiently. Once your labels come off the printing press, you can use an Inspection Slitter Rewinder to finish the labels in one pass inspect, edit, slit and rewind—rather than in multiple steps such as doctoring offline before or after slitting. The inspection rewinder is meant to perform the final and only operation after the printing process.
Which slitting system is best?
The slitter cartridge you choose should be selected based on the stock you work with. Many KOR machines are built for easily interchangeable slitter cartridges so you can swap them in and out if you require multiple types. Another great option is a 2-in-1 slitting cartridge, which combines a conventional rotary shear cartridge with a razor cartridge. In this way, both units are in the machine allowing the operator to easily switch between slitter tools as the job warrants.
The three most common types of slitter cartridges are:
Rotary shear Best for: Pressure-sensitive labels on paper and film liners. How it works:A series of male and female rotary knives that run against one another creating the same effect as scissors. Good to know:Rotary shear knives typically offer the best quality of cut but take the longest to set up when adjusted manually. A faster option is KOR’s proprietary auto-positioningrotary slitter cartridge. This is also safer for operators and offers greater accuracy.
Razor Best for: Films. How it works: Creates a controlled “crack” immediately in front of the blade’s edge the way an X-Acto knife cuts. Good to know: This is the fastest and easiest slitting tool to set. The use of specialty carbide razor blades increases the life and performance of this method. In addition, razor cutting into a driven brush roller improves slit quality on wider filmic webs.
Score cut/crush cut Best for: Thick laminates and industrial labels. How it works: A rotary blade is pressed into a hardened anvil roller. This works much the same way as a pizza cutter. Good to know: Score cut knives are very easy to set and offer versatility for a multiplicity of specialty substrates.
Do you make servo machines?
Yes, today most KOR rewinders are made with servo drives. The number of servo drives installed differs between models.
What kind of automatic vision system do I need?
The vision system is dictated by the size of the defect you're dealing with and the area (size) that needs to be inspected. Generally speaking, entry-level vision systems detect defects > 1 mm² (0.4”²) and high-end vision systems pick up defects of < 1 mm² (0.4”²). The tolerances depend on the vision system’s specifications; for example, an entry-level vision system can check a barcode for print defects, but will not verify or grade the barcode itself. Please contact a representative of the vision system manufacturer in order to have your application assessed for the correct technology.
How do you control tension?
We're extremely proud of our tension control system, which has been perfected over 30 years. The core of our tension control system are the load cells, which read the tension and adjust the torque to the rewind shafts. In machines with a differential rewind, the machine automatically adjusts the air pressure in the rewind shafts, which in turn adjusts the rewind tension to match the load cell readings. This establishes the perfect tension for the base tension setting, taper tension setting and current roll diameter.
Is there an operator’s manual for my machine?
Yes, there is an operator’s manual that comes with every KOR machine. If you do not have yours, please contact us with the serial number of your machine and we will email you a digital copy.
Why won’t the unwind sensor read the correct diameter?
There are two modes of acquiring unwind roll diameter on most machines: direct using an ultrasonic sensor, and calculated using encoders of the unwind and main drawhead motors. The answer depends on the settings in machine parameters, but the latter scenario is the most common–the ultrasonic sensor gives only the initial start diameter at the beginning of the run and then the system is calculating the actual diameter.
If you have an incorrect readout while the machine is at a standstill, that points to the sensor, but over one to two rotations of unwind roll the readout on the screen should show the proper value. The solution is to replace/recalibrate the sensor or simply check if it actually points to the center of the shaft/roll. If the starting diameter is okay and after some run it starts to show the wrong value, the root cause could be in one of several places, so more troubleshooting will be required. To recalibrate the sensor, please see your operator’s manual.
Why is the machine in idle mode with no alarms?
If you hear one long (first) beep but the machine is at a standstill, it's likely that some of the tensions are not in the range and the machine is waiting for loadcells to say that tension is okay to start. Try to push/pull the web by hand on the unwind side of the machine, then on rewind(s) (while holding the JOG/RUN button).
If the machine will start, then this is the issue. To correct it, adjust the parameters (tension settings) on the side that you were touching.
If the machine will not start, the issue might be the STOP button (it’s typically closed, but it doesn’t have a contact) or one of the joysticks (the same situation). The stop contact should be closed in order to start the machine.