When it comes to rewinding, the center-surface winder provides a higher quality since the rewind point is always the same. In this technique, neither the rewind diameter nor the rewind point has an impact on quality. Thus, the same distance is always guaranteed between the slit and rewind point while maintaining material stability. Furthermore, since the rewinder leans on the rewind lay-on roller there is no flexion in the resulting reel, thus obtaining better results. This system also has a web driver between the slitting station and rewinder to help improve the quality of the final result.
This system has considerable advantages when compared to current central rewinding systems. According to the above, a central drum machine with independent arms and a centersurface rewind system will produce better quality and a better product profile at high speeds. In addition, the machine can reach large rewind diameters, suitable of a conventional duplex or turret slitter.
However, despite the higher rewind quality of this system, the market adopted the central rewind system as the standard due to productivity reasons since a central drum machine has slower changeovers. Furthermore, central rewind machines are more versatile, profitable and easier to use and can provide acceptable quality rolls. It was upon these premises that the Duplex machines (double rewind shaft machine for slitting flexible material) and later the Turret machines (for improved productivity) were designed.
The main disadvantage of the Duplex slitter-rewinders is their low productivity. If we consider stop times for splicing, parent reel changes, knife changes, rewind stops for removing reels and inserting new sleeves (generally in work changes and orders), the total stop time can reach up to 70% with only 30% production time. Even so, this system still remains much more productive than a Central Drum machine (considering the mid web sector with diameters no larger than 600-800mm). On the other hand, the turret system reverses the numbers. With the same amount of change jobs as a Duplex machine we obtain productivity results of 30% stop time (stops, parent reel changes, jobs, etc.) and 70% production, considering that a turret machine is always calculated to produce at least 40% more than a double shaft Duplex machine.
Take the production of BOPP 50μ, input diameter in unwind Ø800mmx1200mm in width = 15254 linear meters. We want to obtain rewind reels each Ø450mmx200mm in width = 3050 linear meters. Considering that the maximum production speed is 400mts/min.
In order to surmount the various disadvantages of both systems, Comexi Proslit has incorporated into its entire Duplex and Turret ranges the ALTS system (advance lineal track system) which has many rewind advantages, making it possible to combine any material imaginable with other traditional systems.
Proslit launches the new S-Turret with the ALWS system (advanced linear winding system) in turret:
Aware of the benefits of center-surface rewinding and the market’s need to increase productivity, the ALWS system (advanced linear winding system) has been incorporated into the S-Turret.
Although the system is not entirely center-surface, it operates as such and has many similarities including:
1. The rewind point is always the same regardless of the rewind diameter, always guaranteeing the same distance between the slit and rewind point.
2. The rewinder leans against the pressure roller, although this system operates with shafts, and the pressure roller is in turn supported at all times by the ends of this shaft. This may improve quality in the Center-Surface system since its horizontal movement maintains contact in the same quadrant of the reel throughout the entire process, without applying pressure or counter-pressure as observed by the absence of an arch.
3. Final rewind diameter up to 1000mm.
While taking advantage of the productivity of the Central Rewind system, with experience in modern machines such as:
1. Versatile and profitable
2. Handling and changes
3. Horizontal rewind pressure roller system or lay-on roller similar to ALTS Proslit.
4. Revolving system (non-stop)
Proslit S-Turret is most definitely the sum of all the advantages of these systems: Center-Surface rewinding to guarantee the best quality, non-stop Turret to maximize productivity and finally the Advanced Linear Winding System.