Slitter Rewinders: Operation, Applications, and Benefits

Our slitter rewinders are an essential tool in numerous industrial sectors, thanks to their ability to cut and rewind flexible materials with precision and speed. In this article, we will delve into how these machines work, their main applications, and the advantages they offer, with a focus on the latest innovative technologies.

What Are Slitter Rewinders?
Slitter rewinders are machines designed to cut non-stretchable flexible materials into reels of varying sizes. This process, known as “slitting” or longitudinal cutting, is performed on materials such as paper, plastic, adhesive films, aluminum, laminated materials (duplex or triplex), and nonwoven fabrics. The rewinding process allows the cut material to be wound onto new rolls, ready for further processing or distribution.

These machines are crucial for ensuring efficient production, minimizing waste, and achieving high-quality results—especially in industries where precision is a key requirement. Most machines are equipped with sensors to ensure accurate cutting and automatic control systems to optimize material tension throughout the process.

A high-performance slitter rewinder can also correct any imperfections in the material roll caused during previous processing stages, such as lamination or printing, restoring the roll to optimal condition for final use.

How Slitter Rewinders Work
The operation of slitter rewinders can be divided into three main phases:

1. Loading the Parent Roll: A large roll of material, known as the parent roll, is placed on the machine using either a “shafted unwinding” or a “shaftless” system. The latter is increasingly common today as it simplifies and speeds up the loading process.
2. Longitudinal Cutting: The cutting unit uses circular blades or razor blades, depending on the type of material being processed, to section the material into defined widths. Our slitter rewinders support both cutting systems simultaneously.
3. Rewinding: The cut material is wound onto new mandrels to form smaller rolls. The finished rolls are then unloaded from the machine using various methods, ranging from simple mechanical forks to more automated and complex ejection and unloading systems, which minimize operator intervention and eliminate the need for manual handling of particularly heavy rolls.

Health and safety aspects play an increasingly important role at every stage of slitter rewinder operation. This is evident in the growing demand for shaftless systems, automated ejection and unloading systems, remote-controlled industrial control panels, rear-view cameras for machine monitoring, and ergonomic command and control stations.

Applications of Slitter Rewinders
Slitter rewinders are used across multiple industrial sectors, including:

Paper and Cardboard Industry: Used to produce paper rolls for packaging, labels, printing paper, and corrugated cardboard.

Plastic Packaging Sector: Enable the cutting of plastic films for flexible packaging, food wrapping films, and bags.

Textile and Nonwoven Industry: Process textile materials such as polyester, cotton, and technical fabrics for industrial, medical, furniture, and automotive applications.

Adhesive Tape and Self-Adhesive Materials Production: Used for cutting adhesive tapes, protective films, and self-adhesive materials for the automotive and construction industries.

Technical Films and Aluminum Processing: Essential for producing technical films, such as those used in the photovoltaic sector, and for cutting aluminum sheets used in packaging and insulation.

Benefits of Slitter Rewinders

1. Precision and Flexibility
   Modern machines ensure a high level of cutting precision, with diversified cutting systems depending on the material type (e.g., razor blade cutting, mechanical circular knife, pneumatic knife). The roll width can be adjusted to specific needs. When friction shafts are chosen for rewinding, they typically use aluminum rings to reduce the shaft’s weight. Thanks to a new ball and roller locking system, the mandrels on the rewinding shaft can be secured more quickly and accurately, minimizing downtime.
2. Waste Reduction
   Advanced control systems help minimize processing waste. Additionally, integrating a motor into the material unwinding phase not only improves tension control but also allows for energy recovery. Energy produced by other motors (typically drive and rewinding motors) can be reused instead of being wasted as heat dissipation. For this reason, our slitter rewinders can be considered truly “green” machines.
3. High Production Speed
   The ability to operate at high speeds without compromising quality makes these machines ideal for large-scale production. Furthermore, rapid and precise splicing systems—available either inside or outside the parent roll, depending on customer needs—help maintain machine threading during roll changes, reducing machine downtime.

Versatility of Materials
Slitter rewinders can process a wide range of materials, making them indispensable for industries with diverse needs. They can be equipped with specific setups for different processing requirements (e.g., cutting non-stretchable film for packaging), allowing companies to start with a cost-effective configuration while ensuring future adaptability for additional applications (e.g., paper cutting). This readiness for future modifications ensures flexibility in response to changing production demands.

Technological Innovations in Slitter Rewinders
With the advent of Industry 4.0, many slitter rewinders are now equipped with:

• • Automation systems for tension and cutting control.
  • Intuitive interfaces for real-time monitoring and adjustment of production parameters.
  • Advanced sensors to detect defects and improve final product quality.
  • IoT connectivity for integration with other production processes and remote monitoring.

Slitter rewinders are a fundamental component in multiple industrial sectors due to their versatility, precision, and ability to optimize production processes. With continuous technological advancements, these machines are becoming increasingly efficient and adaptable to the needs of an ever-evolving market.

For example, in their IS version, TEMAC machines are designed for the integration of laser units, micro- and macro-perforation units, positioned between the unwinder and rewinder, typically before the cutting phase. The material is guided by passage rollers either below or above (as per customer preference) the additional platform where the operator is stationed.