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As industries seek innovation and efficient packaging solutions, multilayer polymer packaging is leading the way. With almost 17% of the worldwide flexible film production, multilayer packaging combines advanced material science and manufacturing processes to deliver superior barrier properties, durability and versatility. Technologies such as co-extrusion, lamination and precision film processing have elevated its capabilities across sectors.
What is Polymer Packaging and Why Is It Important?
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Polymer packaging is a material based on plastic, and its usage ensures that products remain safe. Its significance lies in its ability to extend shelf life, ensure product integrity and enhance visual appeal.
Key Benefits of Polymer Packaging:
- Barrier Properties: Shields against moisture, oxygen, UV radiation, and contaminants.
- Mechanical Strength: Aids resistance to puncture, tear, and compression.
- Aesthetics & Printability: Enhances aesthetics through glossy, customizable finish, offers treatable surfaces for high-quality, durable printing.
What is Multilayer Packaging?
Multilayer packaging involves combining two or more layers of different polymers either through co-extrusion or lamination to achieve a high-performance packaging structure.
Common Production Techniques:
- Co-extrusion: Simultaneously melts and layers polymers to form a unified film.
- Lamination: Bonds pre-formed films using adhesives (dry/wet) or molten resins.
- Blown & Cast Film Processes: Ensures control over film thickness, clarity and uniformity.
Common Structures:
1. 3-Layer Films
The 3-layer coextruded films find application in simple tasks such as packaging snacks and protecting surfaces; they are prepared when three different types of polymers are extruded to form a single structure.
Applications:
- Snack packaging
- Surface protection film
2. 5-Layer Films
The 5-layer coextruded films provide more flexibility and performance rates compared to 3-layer structures. They do away with secondary adhesive lamination and are ideal for lightweight packaging.
Applications:
- Cereal liners
- Medical device packaging
- Frozen food (fin or lap seal)
3. 7-Layer Films (or more)
7-layer, high-barrier coextruded films are a big breakthrough in the packaging industry. These are vacuum films and long shelf life products, requiring higher strength and barrier properties are essential.
Common uses:
- Vacuum packaging for meat, rice, and aquatic products
- UHT milk and edible oils
4. 9-Layer Films
9-layer films improve upon the 7-layer model by optimizing cost-performance ratios through strategic layering (e.g., splitting skin layers). They are particularly effective in thermoform-fill-seal applications and provide a high oxygen barrier and formability.
Applications:
- Fresh meat and seafood
- Sausages and cured meats
5. 11-Layer Films
The most advanced in the multilayer packaging spectrum, 11-layer co-extruded films are designed for demanding food and medical applications. Made using PP, EVOH, and nylon-based structures, these films offer:
- Excellent oxygen and aroma barriers
- High transparency and gloss
Application areas include:
- Retortable pouches for meat and dairy
Medical equipment packaging
Functions of Different Layers
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Now, this is how the effectiveness of the three layers of the packaging works:
- Outer Layer: The packing will be a protective skin, hence it is resistant to force, firmness, and good finishing, which is provided by the outer layer. It offers printability of branding information and product details, and is resistant to scratches and UV rays that may destroy the contents.
- Such materials as PET and OPP are typical, durable, shiny, and can maintain the shape and attractiveness of the packaging through handling, storage, and transportation.
- Barrier Layer: This shield will protect products against external attacks such as oxygen, moisture, odours, and gases. It preserves the food, maintains the quality of food by inhibiting contamination, and prevents food deterioration by slowing spoilage, thus increasing shelf life and ensuring food is fresh in terms of taste, smell, and appearance.
- EVOH, nylon, and aluminium foil are usually used, which have very high resistance to penetration and are crucial in the sensitive areas of food, drugs, and other products that require complete protection.
- Adhesive (Tie) Layer: Some packaging materials are not naturally bonded; hence, an adhesive or tie layer is needed. It is a strength-bonding agent because the inherently incompatible layers do not peel or separate with time.
- This important bond between the PE or PP resins used in packaging and the products packaged is commonly made through modified PE or PP resins. This bond can withstand stress without delamination, allowing greater durability and functionality of the packaging product during its life.
- Sealant Layer: This is the innermost layer, which comes in direct contact with the product, and is safe and usable. It forms a removable and heat-sealable enclosure, and the package can be sealed and again opened whenever required.
- It safeguards goods and ensures they are not contaminated because the materials used are food-safe and the seal is durable. Such a layer is vital in such items as snacks, liquids, and medications, ensuring product integrity, and that the cover offers airtight closure, thus maintaining the freshness.
Common Polymers Used in Multilayer Packaging
These materials are blended or layered depending on the specific product requirement.
Polymer | Properties |
Soft, flexible, low melting point | |
Its properties would be High flexibility, toughness, and puncture resistance | |
Rigidity and moisture resistance, excellent chemical resistance | |
Strength, clarity, print quality, and good gas and moisture barrier properties | |
Mechanical strength and heat resistance, chemically inert, with excellent fatigue resistance | |
Superior gas barrier | |
Softness and sealing ease | |
Nylon (Polyamide) | Aroma barrier and toughness, abrasion resistant |
Total barrier against gas, light, and moisture (non-polymer) |
Key Advantages of Multilayer Packaging
Multilayer also possesses quite a variety of functions and trade benefits, which allow multilayers to be applied in the modern food, pharmaceutical, and personal care sectors:
- Customised Performance: Combine layers for product-specific needs.
- Improved Protection: Largely enhanced gas and moisture barrier capacity.
- Material Efficiency: Reduces the cost of logistics due to lightweight yet strong components.
- Extended Shelf Life: It is especially crucial in the food and pharma industry.
Conclusion
Multilayer polymer packaging is a brilliant engineering solution that can fulfil the needs of contemporary consumers. With the sustainability targets on a global level being increasingly strict, it is highly important to innovate to more recyclable and biodegradable solutions.
Innovators such as NICHEM are already paving the path with BioX & Recycling Additives, enabling industries to migrate to a circular economy and maintain their performance. Smart but also sustainable solutions are the future of packaging.
About NICHEM
Long-standing Specialty Chemicals player with ISO 9001:2015 certification and a history of providing specialty solutions for over 25 years. The company is headed by senior chemical industry specialists with the combined expertise of more than 100 years. With an emphasis on eco-friendly, non-toxic products, the company’s primary strength is research, development, and customisation. More information on NICHEM can be found at https://nichem.solutions
