覆膜纸
Laminated paper
——
The core of the coated paper: The molten PE resin is extruded and thermally applied onto the surface of the paper, and simultaneously bonded with another functional layer to form a three-layer structure of paper/PE/membrane. The PE layer serves both as the bonding medium and the main barrier layer. The outer layer can be selected from transparent PE, CPP, PET, OPP or aluminum-coated film: CPP is flexible, PET is stiff, OPP is bright, and the aluminum-coated film provides excellent water vapor and oxygen barrier properties as well as metallic luster.
This material is commonly used for: disposable knife and fork packaging (using PE for oil and moisture resistance), sugar packets (coated aluminum film to prevent clumping and preserve aroma), tea bags (PET to enhance stiffness and sealing performance). Compared to dry composite, laminated composite has no solvent residues, lower cost, and can be directly heat-sealed, and is widely used in high-barrier ready-to-eat packaging.
铝箔纸
Aluminum foil paper
——
Aluminum foil is classified by structure into three-in-one (paper/PE/Al) and four-in-one (paper/PE/Al/PE). The outer layer of the three-in-one type is aluminum foil, which cannot be heat-sealed but can only be folded or clamped. It is commonly used for hamburger, sandwich packaging, and barbecue packaging bags, taking advantage of the heat reflection and oil separation properties of aluminum foil. The four-in-one type adds a PE heat-sealing layer on the inner layer, allowing for direct heating and sealing, achieving complete closure. It is suitable for small packages such as cream, coffee, and disposable wipes, effectively preventing moisture, oxygen, and light from penetrating, thus extending the shelf life. The core of both types is the aluminum foil as the high barrier layer. The difference lies in the presence or absence of the PE layer on the innermost layer.
淋膜纸
Coated Paper
——
The coated paper is composed of two layers: paper and PE. Through the coating process, the PE is melted and applied onto the surface of the paper. The PE layer endows the paper with heat-sealing and water/oil-proof properties, and it is cost-effective and easy to process. It is widely used in scenarios such as hamburger packaging (oil-proof), granulated sugar small packages (moisture-proof), disposable knife and fork packaging (heat-sealing), etc. It does not rely on aluminum foil or high-barrier membranes and is suitable for foods and daily necessities with short shelf life, no need for light protection, or high oxygen barrier requirements.
可降解淋膜纸
Biodegradable coated paper
Biodegradable coated paper is an eco-friendly packaging paper made by using a base paper coated with biodegradable polymer materials (such as polylactic acid, PLA). It offers waterproof, oil-proof and heat-sealing properties similar to those of traditional polyethylene (PE) coated paper. However, under industrial composting conditions, its coating can degrade into water, carbon dioxide and organic matter without generating microplastics, making it environmentally safe. The paper itself is recyclable and suitable for disposable food packaging like paper cups and takeout containers. By providing a sustainable solution to reduce white pollution, it promotes the development of green packaging and contributes to environmental protection.
Differences between PE coated paper and biodegradable PLA coated paper
The coating on ordinary coated paper is plastic, hard to degrade and causes pollution. On biodegradable coated paper, the coating decomposes naturally into water and carbon dioxide, making it safe and eco‑friendly.
