What is Flexible Packaging Film?
Flexible packaging film refers to packaging made from flexible materials. This film can be tailored to fit the shape and size of the product. Its primary materials are flexible substances, such as plastic film, metal foil, and paper. These materials create flexible packaging film. They go through several processing steps and modifications. This results in advantages such as low cost, convenience, and diverse functionality, making it easy to handle and fold. Flexible packaging is widely used in many areas. These include snacks, beverages, pharmaceuticals, personal care products, and shipping goods. Since polyethylene blown film technology emerged in the 1950s, flexible packaging film has become the main choice for many industries. This includes food, pharmaceuticals, and personal care products. Numerous renowned brands, including Coca-Cola and Nestlé, rely on it to ensure product freshness and visual appeal.
Flexible Packaging Film Production Process
Step 1: Resin Selection
First, choose the right material before starting flexible packaging production. This choice should depend on the unique properties of each material. This helps create products with specific functions. Common materials include; this step is important. Different resins affect the packaging’s flexibility, transparency, and protective features. Potato chip bags need clear polypropylene. Frozen foods require low-temperature-resistant polyethylene.
Aluminum: For products requiring high barrier properties, aluminum foil is the optimal choice.
Paper: Ideal for eco-friendly packaging that needs no sealing. This includes dried fruit bags, tea packaging, and gift paper bags. It’s eco-friendly and has a natural feel. This makes it popular with brands that care about sustainability.
Plastic: Polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) are frequently chosen for their long service life and waterproof properties.
Polyethylene (PE): Offering excellent flexibility and cost-effectiveness, it is one of the most widely used materials.
- Common applications include frozen food bags, shrink wrap, and heavy-duty packaging bags. Its flexibility helps package irregular items like frozen dumplings or seafood. This makes it cost-effective and popular among manufacturers.
Polypropylene (PP): Offers exceptional transparency and heat resistance, enhancing product aesthetics.
- Common applications include snack packaging (e.g., potato chip bags), transparent candy wrappers, and microwave-safe food containers. Consumers can see products directly through the packaging, which boosts purchase appeal, while microwave compatibility ensures added convenience.
Polyvinyl Chloride (PVC): Offers stability, chemical resistance, and excellent electrical insulation. It is primarily used in the construction and transportation industries, with limited applications in the packaging sector.
- Common uses: construction applications like pipes, roofing, and flooring; insulation for electrical wires and cables. PVC is being replaced more often in flexible packaging. Eco-friendly materials like PET and PE are now popular. This change supports green packaging trends.
Step 2: Extrusion
Through extrusion, resin is transformed into a uniformly textured film. Here are some common extrusion methods: This stage melts resin pellets at high temperatures. Then, it forms thin, strong packaging base materials. The entire process requires precise temperature control and cooling.
Blown Film Extrusion:
This method extrudes resin to form bubbles. Then, it cools and compresses these bubbles into flat film.
Characteristics: Creates films with strong longitudinal and transverse strength. It also has great tear resistance.
Applications: Packaging requiring high toughness, such as shopping bags and trash bags. Blown film extrusion inflates molten plastic into a tubular shape like a balloon, cools it flat, and winds it onto a roll. It is particularly suited for producing large-roll, heavy-duty packaging film.
Cast Film Extrusion:
This process involves placing molten material onto a chill roll, where it solidifies into a film.
Characteristics:The film is highly transparent, has a uniform thickness, and seals well with heat.
Applications: Ideal for food packaging and the production of composite substrates. The casting process creates a smooth, uniform finish akin to pouring chocolate, making it suitable for packaging that requires an elegant appearance, such as confectionery and medical supplies.
Biaxial Orientation (BOPP, BOPET):
The film is stretched in two directions. This process improves its properties.
Characteristics: Offers high barrier properties, stability, and excellent printability.
Applications: Ideal for packaging food, tobacco, or pharmaceuticals, as well as for printed labels. Biaxial orientation realigns molecules, making the film tougher and smoother. It is commonly used for the outer layer of potato chip bags, producing a “crinkle” sound and resisting tears.
Step 3: Printing
Rotogravure Printing
- Advantages: Exceptional image reproduction, rich color saturation, and the capability of achieving photo-quality printing results.
- Suitable for premium products that demand the highest visual quality, such as high-end pet food and cosmetic packaging. Rotogravure is perfect for long runs of high-end packaging. This includes famous cosmetics and pet food brands. It produces vibrant colors that last and have a strong visual impact.
Flexographic Printing
- Advantages: Rapid plate production, relatively low cost, and high production speed make it highly suitable for mass production.
- Suitable for: packaging with relatively simple patterns and distinct color blocks, such as supermarket shopping bags and generic food packaging.
After extrusion, the film can be printed with brand logos and product information. Two popular printing methods work well for mass production. Printing is not just decoration; it also connects brands with consumers. Clear graphics and information enhance product trust and purchasing intent.
Step 4: Coating and Lamination
This is a critical step where multiple layers of material are bonded together to enhance toughness and high barrier properties. There are two primary methods: Lamination functions like layering protective garments on a film—an outer layer for scratch resistance, an inner layer for freshness preservation, and a middle layer for oxygen barrier, with each layer complementing the others’ functions.
Solvent-based lamination (solvent-based lamination): This process uses solvent-based adhesives to bond layers. As the solvent evaporates, it forms a stable bond. While traditional solvent-based lamination offers strong adhesion, the solvent requires time to evaporate. It is now primarily used in applications that demand exceptional strength.
Solvent-free Lamination (solvent-free lamination): This represents a more environmentally friendly option, as it requires no solvents, relying solely on heat and pressure to bond layers. Solvent-free lamination is a greener and safer option, particularly suitable for food contact packaging, and has become the mainstream trend.
Step 5: Conversion
This is also a crucial step requiring meticulous attention to ensure precise cutting for accurate packaging dimensions.
- Slitting: The initial film is cut into smaller, convenient sizes for use.
- Folding and Sealing: The cut packaging film is formed into small pouches. Additional features, such as seals or openings, may be added at this stage.
- Die Cutting: The film is cut into custom sizes and shapes according to user requirements.
Bag Production
This final production stage involves converting film into packaging bags using specialized bag-making machinery, enabling the creation of a diverse range of bag types. Subsequently, holes can be punched according to specific bag requirements. Alternatively, small components such as zippers, handles, or spouts can be added.
The types of bags produced include:
- Sealed bags
- Three-sided seal bags
- Flat pouches
- Stand-up pouches
- Zipper bags
- Spout pouches
Quality Inspection of Flexible Packaging Film
After undergoing the aforementioned manufacturing process, flexible packaging film undergoes specific tests to meet regulatory standards. These typically include the following:
- Tensile Strength Test: Evaluates the packaging bag’s ability to withstand stretching and resist tearing.
- Seal Integrity Test: Ensures the reliable sealing integrity of the packaging bag to prevent leakage.
- Barrier Testing: Evaluates whether the packaging bag’s barrier properties remain intact.
Choose BestY Pack
From manufacturing to final delivery to your doorstep, we strive for perfection in every step and production method. We ensure our finished products boast beautiful, elegant appearances and flawless, comprehensive performance. As society moves forward, the focus on protecting the environment and recycling is growing stronger. BestY Pack’s products provide the perfect solution to your needs—making us your unparalleled choice! With our professional team and advanced equipment, we deliver one-stop service from design to delivery, empowering your products to stand out in the marketplace.