What Is Rewinder in Paper Machine?

In a paper machine, a rewinder is a crucial component that is responsible for converting large paper rolls produced by the papermaking process into smaller, more manageable rolls. The primary function of the rewinder is to cut and rewind the paper into rolls of specified widths and lengths, making it suitable for various end-use applications. The rewinding process occurs after the initial papermaking and drying stages.

Here are the key features and functions of a rewinder in a paper machine:

Features and Functions:
Reel Unwinding:

The rewinder starts with the unwinding of the parent paper roll, also known as the jumbo roll or master roll. This jumbo roll is typically produced by the paper machine during the manufacturing process.
Slitting and Cutting:

The rewinder is equipped with slitting and cutting mechanisms that allow it to cut the wide jumbo roll into narrower strips. These strips may be of different widths, depending on the specifications of the end product or customer requirements.
Web Control:

Sophisticated web control systems ensure the proper alignment and tension of the paper web during the rewinding process. This control is essential to achieve accurate and consistent results.
Quality Inspection:

Some rewinders are equipped with sensors and inspection systems to detect and reject any defects or imperfections in the paper, ensuring that only high-quality paper is wound onto the new rolls.
Spooling and Winding:

The rewinder winds the cut paper strips onto new rolls, creating finished rolls of paper. The winding process can involve layering the paper in a specific pattern to achieve desired characteristics in the finished rolls.
Reel Changeover:

In some cases, rewinders are designed for continuous operation with automatic reel changeover. This allows for a seamless transition from one jumbo roll to another without interrupting the production process.
Tail Threading:

The rewinder may have tail threading systems that assist in threading the beginning of the paper web from the expiring jumbo roll to the new reel seamlessly.
Automatic Controls:

Modern rewinders often feature automation and programmable logic controllers (PLCs) to control and monitor the rewinding process. This includes setting parameters such as roll diameter, tension, and cutting specifications.
Finished Roll Handling:

Once the rewinding process is complete, the finished rolls are ejected from the rewinder. These rolls can then be transported to downstream processes or prepared for shipping.
Types of Rewinders:
Center Rewinder:

The jumbo roll is rewound onto a core in the center of the roll.
Surface Rewinder:

The jumbo roll is rewound onto a surface without a core, and a core is added later.
Center-Surface Rewinder:

Combines features of both center and surface rewinders, allowing flexibility in core use.