Paper Jumbo Rolls Cutting Rewinding Machine

A Paper Jumbo Roll Slitter Rewinder (often just called a "slitter" or "windermachine") is an industrial machine designed to convert large, master (jumbo) rolls of paper—which come directly from the paper mill—into smaller,

narrower rolls of a specific width and diameter that are ready for use on packaging, printing, labeling, or other converting equipment.

1. The Purpose: Why is it Needed?

· Economies of Scale: Paper is manufactured in very wide (e.g., over 10 meters) and large-diameter jumbo rolls for efficiency and

cost-effectiveness in transportation and handling.

· End-User Requirements: Final customers (e.g., a newspaper printer, a cardboard box factory, a label maker) need rolls that fit their

specific machinery, which require much narrower widths and smaller diameters.

· Quality Control: The rewinding process allows for inspection of the paper web, removal of defects (splicing), and ensures the

finished rolls are wound with precise tension and hardness for optimal performance on downstream equipment.

2. Key Components of a Slitter Rewinder Machine

A modern slitter rewinder is a complex system comprising several key stations:

1. Unwind Stand: Holds the jumbo roll. It can be a single or dual position (to allow for continuous operation by splicing a new jumbo

roll to the tail of the expiring one). It features a braking system to control back-tension.

2. Web Guide System: A critical sensor-based system that ensures the paper web runs perfectly centered through the machine,

preventing misalignment and uneven edges on the finished rolls.

3. Tension Control System: Precisely manages the pull of the web through the machine. Proper tension is vital for preventing wrinkles,

stretching, or loose winding.

4. Slitting Section: This is where the wide web is cut into narrower strips. There are two primary slitting methods:

   · Razor Slitting / Score Slitting: A sharp, stationary razor blade presses against the web, scoring and breaking it along a precise line. Ideal for softer papers like tissue, kraft, and some packaging grades. It's simple and cost-effective.

   · Shear Slitting: The most common method for precision slitting. It uses two matched, rotating circular blades: a top "male"

blade (the slitter) and a bottom "female" anvil ring or blade (the holder). The web passes between them, and the action is like scissors, producing a clean, burr-free edge. Essential for coated papers, films, and labels.

5. Rewind Shaft: The core of the machine where the slit strands of paper are rewound onto new cores. Modern machines use automatic shaftless chucks for faster loading and unloading.

6. Spreader Rolls / Bows: These are bowed (curved) rolls that spread the web outwards, eliminating wrinkles and ensuring a flat,

even sheet enters the rewinding section.

7. Dancer Roll: A weighted or pneumatically controlled roller that moves up and down to absorb tension variations, providing a smooth,

consistent feed.

8. Control System: A centralized PLC (Programmable Logic Controller) and HMI (Human-Machine Interface) touchscreen.

This is the brain of the machine, allowing the operator to set all parameters (widths, lengths, tension, speed) and monitor the process.

3. The Slitting and Rewinding Process (Step-by-Step)

1. Loading: The jumbo roll is loaded onto the unwind stand using an overhead crane or forklift.

2. Threading: The lead end of the paper web is manually or automatically threaded through the various rollers, the slitting station, and attached to the core on the rewind shaft.

3. Setup: The operator inputs the desired finished roll widths, diameters, and tension settings into the control panel. The slitter blades are positioned accordingly on their shafts.

4. Running: The machine is started. The web is pulled from the unwind stand under controlled tension.

5. Slitting: The wide web passes through the slitting station, where it is precisely cut into multiple narrower webs.

6. Rewinding: Each individual slit web is wound onto its own core on the rewind shaft. Advanced systems use individual torque-controlled motors for each position to ensure perfect roll hardness.

7. Unloading: Once the preset diameter or length is reached, the machine stops. The large parent roll of finished smaller rolls is removed from the shaft, and the individual rolls are separated for packaging and shipping.