Multi-layer Forming Film is a technologically advanced type of plastic film designed to meet demanding packaging, thermoforming, and industrial requirements. By combining two or more polymer layers with different properties, the film delivers enhanced strength, barrier performance, processability, and product protection. In this article, we will walk you through the manufacturing process of multi-layer forming film, outline key material and equipment considerations, highlight quality control points, and briefly introduce a reliable supplier that you can partner with for this type of film.
The first step in manufacturing a multi-layer forming film is selecting appropriate polymers and designing the layer architecture. Each layer is chosen for its specific contribution: barrier protection, heat-sealability, rigidity, clarity, or slip / anti-stick performance. For instance, you might combine a polyethylene (PE) layer for flexibility and moisture resist- ance with a nylon (PA) or ethylene-vinyl alcohol (EVOH) layer for oxygen barrier.
Key material considerations:
Barrier layer: such as EVOH, PA, or PET, which blocks oxygen, aroma or moisture.
Sealant layer: a lower-melting polymer which enables heat sealing.
Structural or carrier layer: to give mechanical strength and dimensional stability.
Tie or adhesive layer: which bonds dissimilar polymers together and ensures integrity of the multi-layer structure.
Outer surface layer: may include slip / anti-stick additives, printability or abrasion resistance.
Thickness and ratio of layers: these must be optimized for performance vs cost.
Often manufacturers will produce a table that defines the typical layer stack-up. For example:
| Layer Position | Polymer Type | Function |
|---|---|---|
| Outer surface | PE (or PP) + slip/anti-stick | Surface durability and printability |
| Barrier core | EVOH or PA | Oxygen, aroma, moisture barrier |
| Carrier layer | PE or PP | Base film strength |
| Sealant layer | LDPE or LLDPE | Heat sealability |
| Tie layers (intermediate) | Adhesive copolymer | Bonding between layers |
By designing an appropriate architecture, manufacturers can tailor the film for thermoforming, vacuum packaging, skin packaging, or blister forming.
Once the materials are selected and the layer design is set, the manufacturing process of the multi-layer film follows extrusion, more specifically co-extrusion when multiple layers are melted and extruded simultaneously.
The typical production steps:
Melting and extruding: Each polymer pellet feed (or sometimes regrind or masterbatch) is fed into its own extruder. The extruder melts the material and conveys it under controlled pressure and temperature to a manifold.
Co-extrusion die: The molten polymer streams are brought together via a multi-layer die so that they form a single film structure with defined layer thicknesses. The die must be precisely engineered to ensure uniform flow and layer distribution.
Film forming (blown or cast): After the polymer exits the die, the film is formed via one of two major methods:
Blown film extrusion: A tubular film is formed, inflated with air, cooled and collapsed into a flat film.
Cast film extrusion: The film exits the die and is drawn over chill rolls for cooling, producing a flat sheet.
Cooling and stabilization: The film is cooled to solidify the structure and allow the multiple layers to bond. Cooling rate, air or water ring conditions, and film tension must be optimized.
Winding and slitting: Once the film is cooled and collapsed (in blown) or drawn (in cast), it is wound into rolls. Afterwards it can be slit into required widths, trimmed of edge defects, and transferred for downstream converting (e.g., thermoforming, bag-making).
Maintaining consistent layer thickness and uniform distribution across the film width is critical to performance. Uneven layers can lead to weak barrier zones, delamination, or compromised sealability. According to industry references, advanced machines now incorporate in-line sensors for thickness monitoring and optical defect detection.
Manufacturers typically monitor:
Total film gauge (thickness)
Individual layer gauge (using thickness measurement tools or X-ray/ultrasound)
Bubble stability (in blown film) or draw-down uniformity (in cast film)
Cooling rate and film tension uniformity
Edge trim quality and center gauge drift
Proper calibration of extruders, die sectioning, and cooling settings ensures the desired mechanical, optical and barrier properties.
After forming and winding, the multi-layer forming film undergoes a series of quality control checks as well as optional post-processing to meet application demands.
Gauge profile: verify thickness uniformity across roll width
Layer integrity: check for delamination, voids, pin-holes, or “fish-eyes”
Barrier performance: measure oxygen transmission rate (OTR), water vapor transmission rate (WVTR) if relevant
Seal strength/peel: for films intended for heat-seal or vacuum forming
Clarity and haze: especially for display or consumer packaging films
Mechanical properties: tensile strength, elongation, tear resistance
Surface properties: friction coefficient, slip/anti-stick, printability
Corona treatment or plasma: enhance surface energy for printing or lamination
Primer or tie-layer extrusion: if additional adhesive bonding is required
Lamination: some applications require film lamination to foil, paper, or other substrates (though true co-extruded multi-layer films often eliminate the need for adhesive lamination).
Thermoforming or converting: for forming tray film, blister film, or skin packaging film
Multi-layer forming films are particularly suited for thermoforming and packaging because they provide combined features such as high clarity, vacuum sealing, barrier protection and printable outer surface. The design can be tailored depending on whether the application is rigid tray forming, lidding film, blister film, or flexible pouch film.
For example:
Food tray forming film may require barrier to oxygen, aroma retention, and strong heat sealability.
Medical blister film may demand very high pin-hole resistance, cleanliness, and reliable seal integrity.
Industrial packaging film may emphasize durability, puncture resistance and dimensional stability during forming.
By adjusting the layer structure, thicknesses and polymer types, manufacturers can meet the specific forming profile (draw ratio, forming depth, heat-stabilization) and end-use performance.
When selecting a supplier for multi-layer forming film, consider their expertise in co-extrusion technology, ability to customize layer designs, quality control systems and responsiveness to form-fill-seal or thermoforming customers. One company worth noting is Jinborun Plastic Co., Ltd. (website: https://www.jinboruncl.com/). Jinborun offers professional custom multi-layer film solutions and has capabilities to design, extrude and convert films tailored for packaging and forming applications. Partnering with a company like Jinborun can help you access advanced film designs, flexible layer architectures and consistent supply for forming film projects.
Manufacturing multi-layer forming film is a complex but well-established process combining material science, precision extrusion, cooling, and quality control. Key steps are: selecting the right polymers and layer architecture; using co-extrusion technology to form multiple layers simultaneously; controlling layer thickness and film uniformity; conducting rigorous quality checks; and converting the film into applications such as thermoforming trays or packaging films. By working with a capable supplier and optimizing each step of the chain, you can ensure a film delivers the exact performance you require: whether that means superior clarity, tight barrier protection, strong heat seal, or structural stability. When you need a partner with experience and customization ability, consider Jinborun as an option.
