Rewinders are an essential part of any tissue converting operation, and their performance largely drives production success. Three- and 4-roll configurations are the current options for rewinders, and each enjoys popularity in the field. As more and more converters gain comparative experience between the two types, however, they are discovering the significant advantages a 4-roll rewinder offers. These advantages generally center around improved roll control and well-designed winding geometry.
Let’s briefly explore the most common themes to help you gain a better understanding of the benefits of a 4-roll rewinder and what they could mean to your operation.
Simple, Full Traction Control
The control process with 4-roll rewinders, like that found in Fabio Perini’s Constellation™, is more smooth and stable than that of 3-roll rewinders:
- By introducing first three, then four roller surfaces in the rewinding cycle, logs are weight-supported throughout winding and easier to control. There are simply fewer parameters for machine operators to monitor or adjust as compared to 3-roll rewinders.
- With up to five driving surfaces (with Punzoncini technology) instead of the triangular winding geometry of 3-roll rewinders, the full traction control of 4-roll rewinders ensures low-torque/low-pressure winding and nearly perfect, uniform roll profiles from beginning to end.
Enhanced Product Quality and Production Efficiencies
With 3-roll rewinding, the core is shot against two winding rolls, then squeezed between them to be moved into the rewinding zone —all while the third roll is in the upper position managing the previous roll expulsion. This results in tissue being wound very densely near the core, log instability and the need for continuous adjustments due to changes in paper characteristics and embossing variations.
In 4-roll rewinding with Constellation, the fourth roll accompanies the core to the rewinding zone with gentle control and starts the rewinding with three rolls instead of two. In addition to providing a uniform, near-perfect winding profile from the very beginning, this design, along with the inclusion of Punzoncini in the case of Constellation, can increase line speed significantly in double digit for soft product because of rewinding stability and elimination of log vibration.
Simplified Line Operations
Four-roll technology eliminates the most critical setup parameters required by 3-roll winding. The parameters that remain are simple and intuitive to set up, and stable, simplifying product switching and automating product replication across machines — a significant help to less experienced operators.
Further, a 4-roll rewinder can absorb certain variations in paper characteristics and fiber mixes thanks to its superior winding profile, strength retention and high-speed bulk development. It also better manages desheeting and long-term product development by offering the widest operating window and bulk development capability in the industry, all of which contributes to driving down the fiber cost per roll.
Log Growth Mapping
Constellation offers virtual positioning of the log in the rewinder geometry at any moment of growth so the winding rolls, controlled by servomotors, can be precisely placed around the log at any time to ensure perfect and delicate rewinding control. The rotation of each roll is controlled by an independent motor. The speed balance between them is soft with little variation. For 3-roll technology there are sudden accelerations that produce shocks to both the tissue and the machine, requiring continuous adjustments as paper characteristics and embossing change.
Increased Product Differentiation, Decreased Costs
With Constellation, the four winding rolls:
- Produce larger diameter logs with the same amount of paper.
- Require less paper to achieve equivalent roll diameters.
- Use more economical base sheets while maintaining desired product attributes.
- Allows for higher roll softness and “spontaneous” log growth that ensures higher production consistency and maximum embossing yield at every point on the roll.
Why Use a 4-roll Rewinder?
Constellation from Fabio Perini is the preferred choice for rewinders since its 4-roll technology radically changes the concept of rewinding in six essential ways:
- Perfect rolls from first to last sheet: Constellation is a technology patented by Fabio Perini S.p.A. that ensures four mobile rolls with independent drives consistently and uniformly accompany logs from the first sheet to the last for unprecedented winding quality.
- No obstacles to production: Constellation provides four points of contact for greater log control and faster winding. With a Punzoncini system to handle structured webs and soft roll production, speeds up to 800 m/minute are possible.
- Absolute quality: Gentle winding preserves decor and finished product quality. Rolls also have greater bulk, even using less, lower-quality or lower basis-weight paper.
- Intuitive interface with easy HMI: The elimination of critical and complex parameters, along with a multi-functional panel (easy HMI) that uses intuitive images for any control, allow less-experienced operators to autonomously “pilot” the rewinder.
- Improved effectiveness: With Constellation the stability of rewinding allows quick and simple product change through an extensive library of pre-set or custom combinations, which helps ensure consistent quality when replicating the same product on different machines, in different plants and over different time periods.
- Safe technology: Most operations are performed directly from the HMI panel, limiting the need to access the machine. If machine accessibility is required, Constellation construction is mechanically simplified to reduce operator risk.
To learn more about the simple advantages a 4-roll rewinder offers an how Constellation could be the solution you’re seeking, reach out to Fabio Perini North America today.