Detailed explanation of the workflow of jelly strip packaging machine
Step 1: Film feeding and forming
Roll material feeding: A composite packaging film (such as PET/PE, which has good barrier and heat sealing properties) is installed on the feeding shaft of the machine.
Guided Forming: The film is pulled out and guided through a series of guide rollers to a critical component - the forming machine. This former is usually a trumpet shaped metal component.
Forming a tube shape: When the film is wrapped around this former, it will be rolled from a flat sheet into a continuous tube shape. The longitudinal edges of the cylindrical shape will overlap together, preparing for the next step of longitudinal sealing.
Step 2: Longitudinal heat sealing
Back sealing: Overlapping film edges are sealed using a longitudinal heat sealing device (usually a pair of heated, continuously rotating rollers or a fixed heat seal). This device firmly seals the overlap of the film under high temperature and pressure, forming the back edge of the jelly strip packaging. Thus, a continuous, bottom sealed tubular packaging bag is formed.
Step 3: Filling and Measurement
Material injection: Jelly liquid is accurately measured by a metering pump (such as a gear pump, piston pump, or servo driven volumetric pump) through a hopper located above the machine.
Filling: The precisely measured jelly liquid is injected into the bottom of the tubular film through a filling tube that extends into the newly formed film tube.
Key point: At this stage, the machine will work through intermittent motion of "pulling film stopping film". At the moment of stopping the film, the jelly liquid is filled to ensure that the material accurately falls into the bag and does not splash onto the seal, affecting the sealing.
Step 4: Horizontal sealing and separation
This is the most crucial and complex step, usually completed by a horizontal sealing device.
Horizontal heat sealing: A pair of powerful horizontal sealing jaws (or clamps) with heating patterns will move synchronously towards each other to clamp the thin film tube filled with jelly liquid.
Upper sealing: Firstly, they will be heat sealed above the jelly liquid surface, sealing the top of the current packaging bag and the bottom of the next packaging bag simultaneously in one operation. This forms an "H" - shaped border.
Cooling and shaping: After heat sealing, the gripper usually maintains pressure and undergoes cooling (sometimes through internal water cooling circulation) to firmly shape the seal and avoid deformation.
Cut and Separate: In the middle of the horizontal sealing clamp, there is a sharp cutting blade embedded. At the same time as the sealing is completed, the cutting blade moves to separate the upper and lower packaging bags from the middle. In this way, a complete and sealed jelly strip is born, and the bottom of the next bag is also sealed, ready to accept the next filling.
Step 5: Finished product output
Collection: The cut finished jelly strips are transported out by gravity or conveyor belt and fall into the collection basket or enter the next process (such as cooling, labeling, and packing).