NRC1600 Automatic Jumbo Paper Roll Slitter Rewinder Machine

kraft paper slitter rewinder machine is a heavy-duty industrial machine designed to convert large, master ("jumbo") rolls of kraft paper into

narrower, smaller-diameter rolls required by end-users. It performs two key operations:

Slitting: Cutting the wide kraft web longitudinally into multiple strips.

Rewinding: Winding these strips onto new cores to create finished, manageable rolls.

Why Kraft Paper Requires a Specialized Machine

Kraft paper is known for its:

• High Tensile Strength: The machine needs powerful drives and robust tension control.

• Thickness and Stiffness: It requires heavy-duty components to handle the load.

• Abrasive Nature: The lignin and fillers in kraft paper wear down standard blades and rollers quickly.

• Dust Generation: Slitting can create significant dust.

Therefore, a machine for kraft paper is built to be more robust and durable than one for lighter materials like tissue or film.

Key Components & Their Kraft-Specific Features

1. Unwind Stand:

   • Heavy-Duty Construction: Built to hold the high weight of a jumbo kraft roll (often 1-3 tons).

   • Motorized Back-Tension: Provides precise control over the unwinding force, crucial for preventing breaks and ensuring tight rewinds.

   • Cantilevered Design: Allows for easier loading of heavy rolls.

2. Web Guide System:

   • Essential for keeping the strong, sometimes stiff, kraft web aligned before it enters the slitter. Prevents crooked slitting and edge damage.

3. Slitting Section (The Most Critical Part for Kraft):

   • Shear Cut Slitting is Standard. This method uses two overlapping circular blades (like scissors) and is mandatory for kraft paper.

     • Bottom Blade (Anvil Ring): Often serrated or carbide-coated for longevity.

     • Top Blade (Male Blade): Overlaps the bottom blade to produce a clean, strong, and dust-minimized cut.

     
     

4. Spreader Bar:

   • A bowed roller that gently spreads the slit strips apart to prevent them from interleaving or wrinkling during rewinding—a common issue with stiff paper.

5. Rewind Section:

   • Center-Surface Rewind is most common. A large, driven drum provides the primary winding force, while the cores on the shaft are driven independently.

   • Dual Rewind Shafts are a major productivity feature. While one shaft is winding, the operator can unload finished rolls and set up new cores on the other, minimizing downtime.

   • Rider Rollers: Often used to press against the new rolls, helping to eliminate air entrapment and produce a very hard, dense roll suitable for shipping and high-speed converting.

6. Dust Removal System:

   • Many machines feature integrated vacuum nozzles at the slitting point to suck away paper dust, keeping the rolls clean and protecting the machine's mechanics.

Typical Applications of the Finished Rolls

The output of this machine is used to make:

• Paper Sacks and Bags: Grocery bags, cement bags, industrial packaging.

• Kraft Wrapping Paper: For parcel protection and pallet wrapping.

• Core and Tube Winding: As the base material for paper tubes.

• Laminates: As a strong base layer for composite materials (e.g., with foil or plastic).

• Gaskets and Masking Materials: In industrial settings.