Roundtable: Slitting and Rewinding
What is the next evolution in slitting/rewinding: What are your customers asking for, and how are you responding to evolving needs?Bryan Stiff, sales manager, North America
Titan Slitter Rewinders
Atlas Converting Equipment Ltd.
011 + 44 1234 852553; www.bobstgroup.com/titan
Demand for shorter print runs in flexible packaging means shorter runs for slitting. As a result, we must continue to examine all aspects of slitting performance to reduce machine downtime between reel sets and jobs, and improve ramp rates both in acceleration and deceleration of winding speeds. High slitting speeds are only viable for high (hence long) production runs. The faster the slitter reaches the desired production speed and the quicker it can stop-these are important parameters for additional short runs.
Mark Andy Inc.
Quality is top of mind for customers-both quality of the printed product and the wound roll being delivered. Customers are asking that inspection machines be integrated into the rewinder for 100% inspection, with defects stopped in a position where they can easily be removed. Customers running thinner films also are asking for more sophisticated tension systems to deliver better quality wound rolls. As substrate thickness decreases, the need for better motion control and roll quality increases.
Comexi North America Inc.
The next evolution in slitting and rewinding will be total integration of the entire converting process. “Just-in-time production” relies on a completely integrated press along with laminating and slitting departments to ensure that customers meet their evolving needs.
How would you characterize this market?Stiff: We see a growing demand for laser perforation, in-line folding and even plasma treatment and web cleaning to be incorporated with the slitting/rewinding process for advanced packaging materials. This puts increasing demands on the slitter, as converters still expect the machine to run at the same speeds without these in-line operations. We also see a trend toward more complex barrier structures in “flexibles” of up to seven layers or more, which impacts slitter performance.
Gourlay: The flexible packaging market is growing and seeing shorter run lengths for jobs. Many of these jobs were once printed on wide-web gravure presses, but shorter run lengths are moving to smaller presses in the mid- and even narrow-web width range.
What features or technologies are now in place to increase either production speed, setup speed or both?Stiff: High-speed slitting is less of a requirement today. It is now more important to concentrate on quick and easy machine setup procedures. Our software design engineers can create setup “wizards” to simplify this procedure. Faster setup becomes a key variable when one considers the growing number of jobs per shift, over a period of six or 12 months.
Gourlay: Our Genesis control system has automated job setup tools such as auto sensor calibration and a human-machine interface (HMI) that walks the user through setup. It also has an inspection management feature that counts individual lanes. Increased productivity is usually accomplished with a faster cycle time of starting and stopping. To this end, the eDrive motion controller provides short acceleration and deceleration times-for a faster total cycle time.
Wolf: Comexi offers technologies to ensure a good balance of production and setup speed on our slitter rewinders. These systems increase speeds while reducing cycle and changeover times. The use of operator friendly computers with job storage files yields fast changeovers. The addition of automatic laser knife and rewind core positioning systems, along with finished rewind roll material handling units, makes this possible.
What roles do sustainability and production efficiency play in these products?Stiff: During the last few years, sustainability of flexible packaging materials has become a major issue. For example, increasing use of biodegradable materials means that we now have to adapt slitting technology to accommodate the processing of these materials on our machines.
Gourlay: Thinner materials are more difficult to run, but are being used to save on costs and help the environment. This trend has driven manufacturers to provide equipment that features better tension systems and motion control. These thin films require precise die cutting. Energy management also is a consideration for future machine development.
Wolf: Comexi has introduced technological advances that have redefined slitting and the entire converting process. These advances promote a more efficient and “green” workflow process.
What innovations in slitting/rewinding do you see in the near future?Stiff: There will be a constant need to improve machine productivity and slit-reel quality. We are looking at enhancements to knife positioning and edge guidance systems, as well as fixed geometric configurations, including reduced web length in the machine to ensure better rewind reel quality. Most important: We must improve the flexibility of the slitting process to cover a growing spectrum of printed and laminated flexible materials.
Gourlay: More customers are asking for turnkey solutions in their finishing equipment. This has driven us to find ways to adapt our product line to integrate third party peripheral products such as bar code readers and vision inspection systems-even tapping into and communicating with the plant’s production management system.
Wolf: Technological innovations at Comexi allow for total redefining of the slitting process. These innovations include closed loop unwind and rewind tension controls, advance linear tracking system (ALTS) for the lay-on rolls and a driven nip roll section to minimize the affects of problem substrates.