USED LARGE PAPER & CARDBOARD POCKET AND ENVELOPE MACHINE

Capitalize on the booming e-commerce and logistics sectors with this heavy-duty Large Paper and Cardboard Pocket and Envelope Machine. Designed to process robust materials, this machine effortlessly converts thick kraft paper and cardboard blanks into durable courier mailers, document pockets, and large-format envelopes. A key highlight is the integrated Strip on Flap System, which automatically applies peel-and-seal double-sided tape for easy closure, alongside a high-precision Glue System for secure side-seam bonding.

Manufacturing heavy-duty cardboard mailers and large document pockets requires equipment capable of handling thick, resistant substrates. This specialized envelope machine is the final, crucial step in this industrial workflow.

1. The Printing Process

Production typically begins on a commercial offset or large-format flexographic press. Large sheets of heavy kraft paper or solid bleached sulfate (SBS) cardboard are printed with courier branding, return instructions, or corporate logos. Because these mailers must endure shipping, the inks used are highly durable and often protected with an aqueous coating.

2. The Die Cutting Process

Once printed, the thick sheets are transferred to an automatic flatbed die cutter. A heavy-duty steel-rule die punches out the specific shape of the pocket or envelope blank. Crucially, the die cutter also deeply scores the cardboard, creating the fold lines necessary to prevent the thick material from cracking when folded later.

3. Print Finishing & Assembly (The Envelope Machine)

The die-cut cardboard blanks are loaded into our Large Pocket and Envelope Machine, where they undergo several high-speed, automated processes:

• Feeding & Folding: The heavy blanks are pulled individually from a friction feeder. Specialized folding plows forcefully bend the thick cardboard along the pre-scored lines to form the side seams and bottom gussets.
• The Glue System: Extrusion nozzles or mechanical glue wheels apply a strong line of hot-melt or cold adhesive to the side flaps to permanently form the pocket.
• The Strip on Flap System: As the envelope moves through the press, an automated tape applicator dispenses a continuous strip of double-sided "peel and seal" silicone tape, cutting it perfectly to match the length of the top closure flap.

The finished cardboard mailers are then compressed and delivered on a shingle conveyor, ready to be bundled and shipped to fulfillment centers.