Next to the paper core roll (i.e. the middle roll) of the plastic packaging bag, a circular or ring-shaped paper piece (usually called an "end plate" or "baffle") is added on both sides. This design has the following main functions:
1. Prevent the plastic film from loosening or slipping
Lateral fixation: The paper pieces on both sides block the plastic film like a "baffle" to prevent the film from shifting to the side, loosening or slipping when rolling, ensuring that the roll is neat.
Avoid "roll collapse": During transportation or handling, the paper piece can resist lateral extrusion and prevent the rolled plastic bag from collapsing and deforming.
2. Protect the edge of the film
Reduce edge wear: The edge of the plastic film (especially the thinner material) is easily damaged or wrinkled during friction. The paper pieces on both sides can isolate external contact and protect the integrity of the edge.
Prevent pollution: Avoid direct contact between human hands or dust and the inside of the film to keep it clean (especially for food packaging).
3. Improve the user experience
Easy to extract: The paper sheets on both sides can guide the plastic film to be pulled out more smoothly (such as plastic wrap, garbage bags), reducing the situation of jamming or tearing.
Stable placement: When the rolled plastic bag is laid flat, the paper sheets on both sides increase the support surface to prevent rolling or tilting.
4. Production and transportation optimization
Mechanical adaptability: Automated packaging equipment (such as slitting machines and rewinding machines) requires paper cores and end plates to cooperate to ensure that the rolled products remain balanced during high-speed operation.
Stacking stability: Rolled products with end plates are easier to store in multiple layers and reduce shaking during transportation.
5. Environmental protection and cost control
Reduce the amount of plastic: Use paper sheets instead of all-plastic end caps to reduce costs and are easier to degrade (in line with environmental protection trends). Lightweight design: Paper sheets are lighter than plastic baffles, saving logistics costs.
The paper baffles are detachable. After the user uses up the plastic bag, the paper core and end plates can be recycled or DIY reused (such as handmade roll cores). This design significantly improves the practicality and reliability of plastic packaging rolls through a simple structure and is a classic solution in packaging engineering.
