specializing in the production of stretch film, adhesive tape, packing tape, etc
The packaging of stretch film must be stretched, and the stretching forms of pallet mechanical packaging include direct stretching and pre-stretching. There are two kinds of pre-stretching, one is roller pre-stretching and the other is electric stretching.
Direct stretching is complete stretching between the tray and the coiled film. This method has a low stretch ratio (about 15% to 20%). If the stretch ratio exceeds 55% to 60%, the original yield point of the film is exceeded, and the film width is reduced. The puncture function is also lost, and the membrane is easily broken. And at a stretch rate of 60%, the pulling force is still very large, and for light goods, it is likely to deform the goods.
The pre-stretching is done by two rollers. The two rollers of the roller pre-stretching are connected by a gear unit. The stretching ratio can be different according to the gear ratio. The tension is generated by the turntable. Since the stretching occurs in a short distance, the friction between the rollers and the film It is also large, so the film width does not shrink, and the original puncture function of the film is also maintained. No stretching occurs during actual coiling, reducing cracking due to sharp edges or corners, and this pre-stretching allows stretch ratios up to 110%.
The stretching mechanism of electric pre-stretching is the same as that of roller pre-stretching, the difference is that the two rollers are driven by electricity, and the stretching has nothing to do with the rolling of the tray. Therefore, it is more adaptable and suitable for light, heavy and irregular goods. Due to the low tension during packaging, the pre-stretching ratio of this method is 300%, which greatly saves materials and reduces costs. The suitable film thickness is 15~24μm.
To sum up, the application range of stretch film is very wide, and many domestic fields have not been touched, and many fields that have been touched have not been used. The market potential is immeasurable. Therefore, we have vigorously promoted the production and application of stretch film.