Multilayer Blown Film Technologies
Your team runs a 3- or 5-layer line. But do they actually understand what each layer does?
Most multilayer film is designed by copying. This course teaches your team to design by understanding.
In many plants, the layer structure is something that was set up years ago — by the equipment supplier, by a previous technologist, or by trial and error. The team produces it, but nobody can explain why the outer layer is 20% and not 30%, what the core layer actually contributes, or what would happen if you swapped the inner layer resin.
When a problem appears — poor sealability, insufficient stiffness, bubble instability — the team adjusts process parameters. But in multilayer blown film, the cause is often in the layer structure itself, not in the settings. And if you don't understand the structure, you can't fix what you can't see.
This course gives your team the logic behind multilayer film construction — so they stop copying structures and start understanding them.
What your team will learn to do:
— Understand the function of each layer — outer (surface properties, printability, resistance), core (stiffness, stability), inner (sealing, slip, adhesion) — and how they work together as a system
— Analyze typical 3-layer film and 5-layer film configurations — symmetric and asymmetric — and understand why each structure is designed the way it is
— Understand co-extrusion: how the melt is distributed in a multilayer die head and how the layers are formed into a single tubular structure
— Control layer ratios and understand how the percentage of each layer affects film properties, process stability, and material cost
— Recognize how bubble formation and cooling behave differently in multilayer blown film extrusion compared to monolayer — and what that means for frost line, thickness uniformity, and film quality
— Make rational material allocation decisions — putting the right resin in the right layer to optimize both performance and cost
Who is this course for?
— Machine operators running 3-layer or 5-layer blown film lines who want to understand how the layer structure affects what they see on the line — bubble behavior, thickness, film properties
— Production engineers and technologists responsible for layer structure design, material selection, and process setup on multilayer blown film extrusion lines
— Quality specialists who need to connect film performance issues with specific layers in the structure
— Production managers and plant directors planning new multilayer extrusion lines, expanding into multilayer production, or evaluating layer design changes for cost optimization
— Companies currently producing monolayer PE film that want to understand multilayer blown film technology before investing in new equipment
Why this course matters
Multilayer film is the future of blown film production — but only if your team understands the technology, not just operates the equipment.
A 5-layer blown film line that runs structures copied from a supplier recommendation leaves performance and cost savings on the table. The team produces film that works, but nobody knows if it could work better, cost less, or use cheaper resin in the core without losing properties.
This course gives your team the ability to think in layers — to understand why a structure is built the way it is, what each layer contributes, and what changes are possible without breaking the system.
The result: structures designed with purpose, better material utilization, fewer "we've always done it this way" decisions, and a team ready for the next step — advanced 7- and 9-layer configurations.
What will you learn?
Types of blown film — monolayer, 3-layer, 5-layer When each type makes sense, what drives the decision to add layers, and the logic behind choosing a film structure based on product requirements.
Layer functions — outer, core, inner What each layer is responsible for and how it contributes to the overall film properties — mechanical strength, surface quality, sealability, and processability.
Typical 3-layer and 5-layer configurations Symmetric and asymmetric structures used in blown film production — how they are designed, why certain combinations work, and what trade-offs are involved.
Co-extrusion — how multilayer blown film is formed How the melt from multiple extruders is combined in the die head and distributed into a layered tubular structure — and where problems can originate in the co-extrusion process.
Bubble formation in multilayer blown film extrusion How the presence of multiple layers affects bubble stability, frost line behavior, and cooling — and why multilayer bubbles behave differently from monolayer.
Designing layer ratios for optimal performance How the percentage of each layer affects film properties, process stability, and raw material costs — and how to find the right balance between quality and cost.
Rational use of raw materials in multilayer structures How to allocate PE resins across layers to maximize performance while minimizing cost — putting expensive resin only where it adds value to the final product.
Course format
— Practical PDF materials covering multilayer blown film logic, layer functions, co-extrusion principles, and layer structure design
— Video and audio explanations for selected topics — co-extrusion flow, layer formation, structure analysis
— Final quiz to verify your understanding of multilayer construction and its effect on film properties and process behavior
— Rolbatch Academy certificate upon successful completion
This course is the foundation for advanced multilayer blown film training.
Parts 1–6 give your team the complete knowledge of the blown film extrusion process — from fundamentals through materials, machine, optimization, supporting technologies, and specialized films. Part 7 opens the door to multilayer thinking — the ability to design film structures, not just produce them. Advanced courses P10 and P11 build directly on this foundation with complex 7- and 9-layer configurations.
See the full course series (P1–P9) →
Practical details
— Access duration: 30 days — learn at your own pace
— Certificate: Rolbatch Academy certificate and diploma
— Available languages: German, English, Polish, Spanish. Other languages upon request
— Price: net price. VAT will be added at checkout where applicable. EU companies with a valid VAT ID (verified in VIES) may qualify for 0% VAT — contact us before purchase.
Questions? Need a quote for your team?
Visit our Contact page for pricing, group discounts, and language availability.
Available in 14 languages — English, German, Polish, Spanish, Italian, French, Russian, Slovak, Czech, Turkish, Chinese, Swedish, Ukrainian, Portuguese.
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