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عربى1. Substrate pretreatment
Paper selection
A three-layer composite structure is used, the core layer is high-strength kraft paper, and the outer layer is selected according to the needs of 120-200g/m² bleached or natural wood pulp paper.
Polymer film matching
Matched with 12-25μm thick LDPE or BOPP film as a barrier layer, the melt index is controlled in the range of 2-8g/10min to meet the heat sealing performance.
2. Composite process
Paper-plastic composite is mainly achieved by the following methods:
Dry composite
Coat substrate (such as plastic film) with polyurethane adhesive (coating amount 2.5-3.5g/m²), and heat-press composite with paper after aging at 40-45℃.
Wet composite
Use water-based acrylic adhesive to complete the bonding of paper and plastic film in a wet state, and then dry and solidify (composite roller pressure 0.3-0.5MPa).
Hot-melt lamination
Use hot-melt adhesive to directly heat and coat, omitting the solvent drying process, suitable for fast production scenarios.
After the composite process, the resulting paper-plastic composite bag exhibits enhanced mechanical properties and improved barrier performance, making it suitable for a wide range of applications. The combination of high-strength kraft paper and a carefully selected polymer film ensures that the bag can withstand stress during handling, transportation, and storage, while maintaining the integrity of the contents. This type of product packaging plastic bag is particularly beneficial in industries where moisture resistance and durability are critical, such as food packaging, chemical storage, and construction materials.
Sustainable paper bags have gained attention in recent years as environmental concerns drive businesses and consumers to seek alternatives to traditional plastic packaging. By utilizing a paper-plastic composite structure, manufacturers can provide a bag that balances environmental responsibility with functional performance. The paper layer can be sourced from responsibly managed forests, and the polymer film can be designed for recyclability or reduced material thickness, thereby reducing overall plastic usage. These sustainable paper bags can help companies meet regulatory requirements, reduce carbon footprint, and support circular economy initiatives without compromising product safety.
The selection of adhesives and bonding methods plays a significant role in determining the performance of a paper-plastic composite bag. Dry composite techniques allow for precise control of adhesive application and are suitable for scenarios where heat resistance is required. Wet composite methods, on the other hand, offer flexibility in adjusting coating thickness and are compatible with various paper and film types. Hot-melt lamination provides a faster production cycle and eliminates the need for solvent drying, which can improve efficiency and reduce environmental impact. Each method can be tailored according to production needs and the desired characteristics of the final product.
In addition to barrier and mechanical properties, the design and structure of the bag can further enhance its functionality. For example, valve bags can facilitate automatic filling and reduce labor requirements, while reinforced bottoms and handles improve handling during transportation. The paper layer also allows for high-quality printing, which is important for branding and product identification. Combining these features with a polymer layer ensures that the product packaging plastic bag can protect contents from moisture, dust, and other external factors, making it suitable for a variety of industries.
The market demand for paper-plastic composite bags continues to grow, driven by the need for durable and sustainable packaging solutions. Food companies increasingly rely on these bags to maintain product freshness while providing a packaging option that aligns with consumer expectations for environmental responsibility. Similarly, industrial and chemical manufacturers use these bags to safely transport materials while producing less packaging waste. By offering a balance of strength, barrier properties, and sustainability, paper-plastic composite bags represent a versatile solution for multiple packaging applications.
Future trends indicate that the development of new adhesive formulations, thinner polymer layers, and enhanced recycling methods will continue to improve the performance and environmental footprint of paper-plastic composite bags. Companies adopting sustainable paper bags as part of their packaging strategy can not only meet regulatory requirements but also respond to growing consumer demand for eco-conscious solutions. As industries explore alternatives to conventional plastic packaging, the combination of paper and polymer layers in a composite structure offers a practical path forward, supporting both functionality and sustainability in product packaging plastic bag applications.
