Industry Q&A: Slitter/winders stay on technology's cutting edge
Brian Stiff, sales manager, Titan Slitter Rewinders (Bobst Group)
Q: What slitting/winding challenges keep your customers awake at night, and how does today’s machinery address these problems?
A: One of the most important aspects of successful slitting technology is producing consistent, high-quality rewind reels. That means reels finished with no telescoping or surface defects.
To achieve this with the increasing sophistication of today’s flexible packaging materials, the slitter has to provide accurate web tension control, good contact pressure from the lay-on rollers and precise slitting. Another key is using the most appropriate composition in the web path rollers, which varies considerably for the many types of materials in packaging.
The slitter also has to cope with substrate defects that occur during printing and laminating. These can be flagged in the unwind roll, but they hinder the productivity of the slitting process as the machine has to stop to remove the defective material, after which the perfect material has to be spliced on. Roll mapping on an upstream machine enables roll defects to be communicated to the slitter, so the operator can anticipate these in advance.
Q: What sorts of technology do you believe will drive further innovation and efficiency in today’s slitter/rewinder operations and why?
A: More automation features are now being requested as standard rather than options. These provide greater machine productivity and more rapid ROI while also meeting the current demands of the converter for slitting operations. A modular machine design enables the converter to upgrade the specification at a later date to meet increased levels of production. Adding automatic knife positioning is a good example of this.
The internet has led to the advent of remote, web-based machine diagnostics, which make it possible to resolve certain operational problems without the need for a service technician to visit and support the customer. Such innovation will surely lead to further developments in the future.
Q: What trends do you see in the flexible packaging market today that will impact the future of slitting/rewinding and why?
A: We are seeing a growing demand for laser perforation, in-line folding and even plasma treatment and web cleaning to be incorporated with the slitting/rewinding process. This has put increasing demands on the slitter, as converters still expect the machine to run at the same speeds achievable without these operations.
The growing use of high performance optical and clear barrier films, multiple-layer laminates and filmic labels has created a range of substrates that are much more sensitive for the slitter to process, with ramifications for production speeds, roll coverings and control of the web path. We also see a trend toward larger rewind reel diameters in certain market sectors and the increasing complexity of barrier structures of up to seven layers, all impacting the slitter's operation.
Titan Sliter Rewinders (Bobst Group)