Application fields of stretch wrap packaging film

The packaging of stretch film must be stretched, and the stretching forms of tray mechanical packaging include direct stretching and pre stretching. Pre stretching can be divided into two types: roller pre stretching and electric stretching.
Direct stretching is the process of stretching between the tray and the wrapping film. This method has a low stretching ratio (about 15% to 20%). If the stretching ratio exceeds 55% to 60% and exceeds the original yield point of the film, the film width decreases, the puncture performance is also lost, and the film is easily broken. And at a 60% elongation rate, the tensile force is still very high, which may cause deformation of light goods.
Pre stretching is accomplished by two rollers. The two rollers for pre stretching are connected by a gear unit, and the stretching ratio can vary depending on the gear ratio. The tension is generated by the turntable. As stretching occurs over a short distance, the friction between the rollers and the film is high, so the film width does not shrink and the original puncture performance of the film is maintained. No stretching occurs during actual winding, reducing the risk of breakage caused by sharp edges or corners. This pre stretching can increase the stretching ratio to 110%.
The stretching mechanism of electric pre stretching is the same as that of roller pre stretching, except that the two rollers are driven by electricity and stretching is completely independent of the rotation of the tray. So it has stronger adaptability, suitable for light, heavy, and irregular goods. Due to the low tension during packaging, this method has a pre stretching ratio of up to 300%, greatly saving materials and reducing costs. Suitable for film thickness of 15-24 μ m.
In summary, the application fields of stretch film are very wide, and many fields in China have not yet been involved, and many fields that have already been involved are not widely used. With the expansion of application fields, the amount of stretch film will inevitably increase significantly, and its market potential is immeasurable. So it is necessary for us to vigorously promote the production and application of stretch film.