BOPP/CPP composite packaging roll film: How to achieve excellent quality through multiple processes?

All excellent products come from high-quality raw materials. The raw materials of BOPP/CPP composite packaging roll film mainly include polypropylene (PP) granules and necessary additives. Among them, the BOPP layer mainly uses high-transparency polypropylene granules to ensure the high transparency of the film; while the CPP layer uses polypropylene granules with good heat sealing and moisture barrier properties to meet the packaging requirements for moisture barrier and heat sealing properties.

In the raw material preparation stage, the manufacturer needs to strictly screen and test the raw materials to ensure that the key indicators such as purity, particle size, and melt index of the raw materials meet the production requirements. At the same time, it is also necessary to add appropriate amounts of antioxidants, anti-ultraviolet agents, slip agents and other additives according to product characteristics and customer needs to improve the film's antioxidant, weather resistance and processing performance.

After the raw materials are prepared, the next step is to enter the film extrusion stage. In this stage, the polypropylene granules are fed into the extruder, heated and melted, and then extruded into a continuous film through the die. Parameters such as the temperature, pressure and extrusion speed of the extruder have a crucial impact on the quality of the film.

In order to ensure the uniformity and stability of the film, the manufacturer needs to accurately control the temperature of the extruder, which usually needs to be adjusted according to the melt index of the raw material and the model of the extruder. At the same time, the extrusion speed needs to be strictly controlled to avoid defects such as uneven film thickness or bubbles.

After extrusion, the BOPP film also needs to be biaxially stretched. Biaxial stretching is a key step in the production of BOPP film. By accurately controlling the stretching temperature and speed, the molecular chains of the film can be fully stretched and arranged in the horizontal and vertical directions, thus giving the film excellent physical properties.

During the biaxial stretching process, the manufacturer needs to strictly control the stretching temperature and speed to ensure that the stretching ratio and tensile strength of the film meet the production requirements. At the same time, the stretched film needs to be cooled and shaped to avoid deformation or shrinkage of the film during subsequent processing.

After biaxial stretching, the BOPP film and the CPP film need to be compounded. The compounding process uses advanced bonding technology to tightly combine the two layers of film by coating adhesive, hot pressing bonding or melt bonding to form a stable composite structure.

The type, coating amount and coating uniformity of the adhesive have an important influence on the quality of the composite film. Manufacturers need to select appropriate adhesives according to the material and purpose of the film, and strictly control the coating amount and coating uniformity to ensure that the bonding strength and peeling strength of the composite film meet the production requirements. At the same time, the composite film needs to be heat-pressed to improve the bonding effect and stability.

The composite film needs to be heat-sealed to ensure that the package can keep the food dry and fresh in a sealed state. Heat sealing temperature, pressure and time are key factors affecting the heat sealing effect. Manufacturers need to adjust the heat sealing parameters according to the material and thickness of the film to ensure that the heat sealing strength and sealing meet the production requirements.

After heat sealing, the film needs to be slit to cut it into the width and length required by the customer. The cutting accuracy and speed need to be strictly controlled during the slitting process to avoid defects such as burrs and tears. At the same time, the slit film needs to be wound and packaged for subsequent transportation and use.

Throughout the production process, inspection and quality control are key links to ensure product quality. Manufacturers need to conduct strict quality inspection and control of raw materials, semi-finished products and finished products to ensure that the various performance indicators of the product meet production requirements and customer needs.

Inspection items include film thickness, transparency, tensile strength, tear strength, adhesive strength, peel strength, heat seal strength, sealing, moisture barrier, etc. Manufacturers need to use advanced testing equipment and testing methods to accurately measure and evaluate the various performance indicators of the product. At the same time, it is also necessary to monitor and record the key parameters in the production process in real time to facilitate the timely discovery and resolution of potential quality problems.

While pursuing product quality, manufacturers also need to pay attention to environmental protection and sustainable development. The waste and wastewater generated in the production process of BOPP/CPP composite packaging roll film need to be properly handled to avoid environmental pollution. At the same time, manufacturers also need to actively develop and promote environmentally friendly composite packaging materials and technologies to reduce the environmental risks and resource consumption of products.

In order to achieve green production, manufacturers can take a series of measures, such as optimizing production processes, improving raw material utilization, using environmentally friendly adhesives and additives, and strengthening waste recycling and reuse. These measures not only help reduce production costs and resource consumption, but also enhance the company's sense of social responsibility and brand image.