BOPP (Biaxial polypropylene) synthetic label paper production raw materials mainly include the following:
First, polypropylene resin
Core raw material: polypropylene resin is the main raw material for BOPP film production, it is a thermoplastic, with excellent physical properties and chemical stability.
Characteristic requirements: The polypropylene resin used to produce BOPP films needs to have a high molecular weight, narrow molecular weight distribution and good processing properties to ensure that the film can form a uniform crystalline structure during the stretching process, thereby obtaining excellent mechanical properties.
Second, auxiliary agents
Type: In the production process, it is also necessary to add some additives to improve the performance of the film. These auxiliaries may include antioxidants, antistatic agents, smoothing agents, etc.
Action: Antioxidants help prevent degradation of the film due to oxidation during processing and use; The antistatic agent can improve the antistatic property of the film and reduce the influence of electrostatic accumulation on the quality of the film. The smoothing agent is helpful to improve the smoothness of the film, which is convenient for subsequent processing and use.
Third, other raw materials (for specific types of BOPP films)
For some special types of BOPP films, such as BOPP pearlescent film label materials, raw materials such as calcium carbonate and pearlescent pigments need to be added to polypropylene resin. The addition of these raw materials can give the film unique decorative effects and performance characteristics, such as light gravity, good decoration.
Fourth, overview of production process
The production process of BOPP synthetic label paper usually includes the following steps:
1.Preparation of raw materials: the polypropylene resin and additives are mixed evenly according to a certain proportion.
2.Extrusion casting: the mixed raw materials are melted and extruded by the extruder to form a certain thickness of the sheet.
3.Bidirectional stretching: The extruded sheet is bidirectional stretching (longitudinal and transverse) in a special drawing machine to increase the strength and toughness of the film.
4.Heat treatment: The stretched film requires heat treatment to eliminate internal stress and improve dimensional stability.
5.Winding and cutting: the film after heat treatment is winding and cutting to obtain a certain width and length of BOPP film products.
6.Subsequent processing: According to the needs of the BOPP film and glue, bottom paper and other materials composite, BOPP synthetic label paper.
In summary, the raw material for the production of BOPP synthetic label paper is mainly polypropylene resin, supplemented by various additives to improve the film performance, and other raw materials are added as needed to give the film specific characteristics. Through strict production process and process control, BOPP synthetic label paper with excellent performance can be produced.