What Is BOPP Film Manufacturing Process?

Bopp film is a very common packaging material, suitable for a variety of products, but do you know the bopp film manufacturing process?
 
There are six main steps in the Bopp film manufacturing process: raw material, extrusion, casting, MDO, TDO, rolling up.
 

Below is a detailed Bopp film manufacturing process:
1. Raw material: The raw material system includes the process of batching, mixing and drying. The raw materials used in the production of Bopp film mainly include homopolymer polypropylene (HPP), stiffening agent, COPP, anti-adhesion agent (AB), anti-static agent (AS) and lubricant.
2. Extrusion: The main tools for this step are the extruder and the filter. The process temperature of extruder is closely related to raw material performance and production speed. Extruder barrel temperature setting process generally higher than that of main ingredient HPP 50 ~ 80 ℃, melting point if the gauge degree of raw materials is higher, the set temperature is relatively higher. The function of the filter is to filter out raw materials or foreign impurities. The number of mesh and layer of the filter should be selected according to the specific situation of production.



3. Casting: This step is to cool the resin out of the die head into a sheet, so that the crystallinity, crystal shape and crystal size of BOPP sheet can reach an ideal state, so that the sheet is more conducive to further stretching, at the same time, the physical and mechanical properties of BOPP film (such as tensile strength, elastic modulus, transparency, etc.) are related to the crystallinity of the film, as well as the size and shape of crystals in the film.
4. MDO: The role of longitudinal stretching is to preheat the sheet from the casting machine and stretch the sheet by the speed difference between the high-speed roller and the low-speed roller.
5. TDO: The function of transverse stretching is to preheat, stretch and shape the film after longitudinal stretching.
6. Rolling up: The process parameters of the system include the width of the film, the speed ratio, the corona treatment strength, the winding tension, the pressure of the floating roller and so on. The width of the film is mainly determined by the requirements of the production plan.
 
The above is the bopp film manufacturing process. If you have any questions, please contact us.