There are two ways for using stretch film hand roll, one is by manual, the other is tray mechanism packing.
1. Begin to wrap up from the bottom
2. When you wrap one by one around the circle and wrap it around the top, you need to wrap the entire top.
3. Finally, hold the scissors and cut the packing tape.
Tray mechanism packing:
Stretch film packaging must be stretched, and the tray mechanical packaging stretches directly stretched and pre-stretched. Pre-stretching is further divided into two types, one is roller pre-stretching and the other is electric stretching.Direct stretching completes the stretching between the tray and the film. This method has a low draw ratio (about 15% to 20%). If the draw ratio exceeds 55% to 60%, it exceeds the original yield point of the film, the film width is reduced, and the puncture performance is also lost. Easy to break. And at 60% elongation, the pulling force is still great, and for light cargoes, it is likely to deform the cargo.
Pre-tensioning is accomplished by two rollers. Roller pre-stretched two rollers are connected by a gear unit. The stretching ratio can be different according to the gear ratio. The pulling force is generated by the turntable. Since the stretching is generated within a short distance, the friction between the roller and the film It is so large that the film does not shrink and the original puncture performance of the film is maintained. No stretching occurs during actual winding, reducing breakage due to sharp edges or corners. This pre-stretch can increase the draw ratio to 110%.
The pretensioning mechanism for electric pretensioning is the same as that for pretensioning, except that the two rollers are electrically driven and the stretching is completely independent of the rotation of the tray. Therefore, the adaptability is stronger, light, heavy and irregular goods are all applicable. Due to the low tension during packaging, the pre-stretching magnification of this method is up to 300%, which greatly saves materials and reduces costs. Suitable for film thickness 15 ~ 24μm.