How to Paper Bag Machine Manufacture Square-bottom Paper Bags

The manufacture of square-bottom paper bags is a complex process that involves various stages, from design to production. The production process of square-bottom paper bags using paper bag machines involves several sequential steps, which are explained in detail below.

To produce high-quality portable square bottomed paper bag products, a high-quality portable paper bag machine equipment is required, such as the fully automatic single sheet portable paper bag machine produced by Chinese manufacturer Hongying Machinery Co., Ltd. This paper bag equipment draws on German technology and is independently developed and designed.

The portable paper bag machine adopts a PLC programmable controller, a touch screen human-machine interface, and full process automation, providing production efficiency dozens of times compared to traditional manual production.

This portable paper bag making machinery is an ideal equipment for producing square bottom tote bags, shopping bags, gift bags, food bags, etc.

The first step of producing bottom paper bags ：
Design and Preparation of the Bag Blanks
The first step in the production of square-bottom paper bags is the design and preparation of the bag blanks. The bag blanks are typically made of kraft paper, which is a strong, brown paper stock often used for packaging. The designers create the bag blanks using specialized software, which generates the patterns for the different parts of the bag, including the front and back walls, the top and bottom edges, and the handles.
Cutting and Creasing
Once the paper bag blanks are designed, they are sent to the cutting and creasing stage, where the paper bag machine cuts and creases the blanks to create the different parts of the bag. The machine uses precision cutters to cut the paper stock according to the designed pattern, while special creasing wheels are used to score the paper for easy folding and assembly.
Folding and Assembly
In this stage, the folded bags are removed from the hopper and inserted between the plates of the bottom Bag former where they are sandwiched between layers of interlocking former plates. Then a forming wheel rotates, smoothing out any wrinkles in the bags and shaping them into a square bottom.
Bottom Sealing
After folding and assembly, the bags move to the bottom sealing stage, where they are joined together at their bottom edges. This is done using pressure rollers, which seal the paper stock by heating and compressing the edges. This creates a strong, leak-proof seal that holds the bag together.
Handle Attachment
In this stage, the paper bag machine attaches the handles to the sides of the bag. The handles are typically cut from a thicker grade of paper stock to provide extra strength and support. The handles are typically attached using a combination of heat and pressure to ensure a secure bond.
Top Sealing and Cutting
Finally, the top edges of the bag are sealed using pressure rollers or a hot-melt adhesive gun, followed by trimming off any excess paper stock using a cutter wheel or blade. This completes the square-bottom paper bag production process.
Quality Control
After each bag is sealed and trimmed, it passes through a quality control checkpoint to ensure that it meets the required standards. The quality control inspectors check for any tears, leaks, or missing components before allowing the bags to proceed to packaging and shipment.