The operation process and process technology of bag cutting and installation of the sliding chain mouth in the production of Hefty Bags Slider (sliding chain bag) are convenient for understanding the factory production links or technical instructions.
1. Bag cutting process
After the film is rolled, the bag making first enters the slitting and bag making process:
1.1 Unwinding: The large roll of blown film is evenly fed into the bag making machine through the unwinding machine.
1.2 Positioning and feeding: Photoelectric sensing or mechanical positioning device identifies the bag length mark (or set length) to ensure that the size of each bag is accurate and consistent.
1.3 Heat sealing & cutting: The high-temperature heat sealing knife (or ultrasonic heat sealing equipment) quickly heat seals the bag edge at the predetermined position and cuts it at the same time to form a single bag body. (Some sliding chain bags will also reserve the bag mouth unsealed for subsequent sliding chain installation)
1.4 Cooling and shaping: The bag edge that has just been heat-sealed is lightly pressed by cooling air or pressure wheel to make the heat seal firm and flat.
2. Process flow of installing the sliding chain mouth
The installation of the sliding chain mouth (sliding chain track + slider) is a key process in the production of sliding chain bags, which requires special automated equipment to complete.
2.1 Automatic feeding sliding chain track: The sliding chain track (double-track seal) is automatically fed into the sliding chain assembly machine in a rolled state and aligned with the bag mouth.
2.2 Positioning assembly: The chain track is precisely aligned with the edge of the bag mouth. The position is firmly fixed by a cylinder, a guide rail or a mechanical clamp.
2.3 Hot pressing and sealing: Through local hot pressing or high-frequency hot sealing, the sliding chain track is firmly melted or pressed on the film layer of the bag mouth to form a firm seal. Some high-end equipment can complete the double-track pressure sealing and bottom sealing processes of the bag mouth at the same time.
2.4 Sliding chain head installation: The sliding chain puller (slider) is automatically embedded in the double-track chain through a manipulator or a guide rail and positioned at one end of the bag mouth. The slider is generally made of PP or high-strength PE and is injection molded once.
3. Sliding test (included in some high-end processes)
Some automated equipment will automatically test the smoothness of the sliding chain after installation to prevent the slider from getting stuck or not smooth.
4. Cooling and shaping
The heat-sealed or heat-sealed parts are shaped after cooling to prevent deformation or loosening.
5. Technical features
The entire bag cutting and sliding chain installation process is fully automated or semi-automated, reducing manual intervention and improving precision. Photoelectric sensing, pneumatic control, and PLC programming control production lines ensure high efficiency and consistency. The tension resistance of the sliding chain assembly and the bag body is usually ≥5N to prevent the sliding chain from falling off during use.
6. Optional extended process:
The installation of hanging holes, writing areas, M-shaped folding edges, etc. can be completed synchronously after the sliding chain is assembled.
Some sliding chain bags use double-track pre-sealing + sliding chain hot embedding process, which has stronger sealing.
