The plastic packaging of special-shaped products (such as bottles with curved nozzles and spray) needs to solve three major technical difficulties:

1. Shape adaptability: Complex surfaces (such as nozzle bends) can easily cause wrinkles or loose wrapping of the film, and pre stretching technology is needed to adjust the distribution of film shrinkage force.

2. Function reservation: active parts such as nozzles and triggers need to be partially plastic free, and die-cutting mask technology is used to precisely control the plastic packaging range (as shown in the figure, the green spray bottle nozzle is not fully covered).

3. Sealing consistency: Irregular structures are prone to stress concentration points, and it is necessary to ensure uniform shrinkage through a multi-stage heat shrink tunnel (temperature controlled in zones of 150-220 ℃).