Walki®Opti Seal
Optimised polymer coating for easy recyclability
Optimised PE-coating for strong seals and high fibre solutions
Optimised PE-coating for circular design

Walki®Opti Seal is a fibre-based, heat-sealable packaging material that combines strong barrier performance with easy recyclability. Its optimised PE-extrusion coating offers reliable water vapour and grease resistance while keeping polymer use minimal, enabling efficient recycling in standard paper streams. Suitable for bakery, dried goods, frozen food and selected non-food applications, it runs smoothly on high-speed lines and provides a natural matt surface with high print quality. Walki®Opti Seal gives brands a practical route towards lower-carbon, PPWR-aligned packaging.
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Walki®Opti Seal brings together high-fibre content, reliable sealing and good barrier protection in one versatile material. The solution is based on strong white or brown kraft paper combined with an optimised PE-coating that ensures durability, seal integrity and excellent machinability. With up to 95% fibre content, it supports brand owners aiming to reduce plastic use without compromising product safety or shelf appeal. Walki®Opti Seal is compatible with flexo, rotogravure and offset printing, offering wide creative freedom.
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Walki®Opti Seal is designed with future recyclability requirements in mind under the EU Packaging and Packaging Waste Regulation (PPWR). Its minimised PE content supports efficient repulping and a high fibre yield. By reducing polymer use and enabling recycling within paper streams, brand owners can lower EPR fees, packaging taxes and CO₂ emissions while progressing towards fully circular packaging portfolios.

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Walki®Opti Seal is ideal for both food and non-food flexible packaging, especially where a combination of strength, barrier protection and heat-sealability is required.
Common applications:
- Bakery goods and dried products
- Frozen food and ready-to-use mixes
- Home and personal care refills
- Industrial packaging
- Flow-packs (VFFS/HFFS), 4-side sealed sachets, overwraps

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Walki®Opti Seal brings together high-fibre content, reliable sealing and good barrier protection in one versatile material. The solution is based on strong white or brown kraft paper combined with an optimised PE-coating that ensures durability, seal integrity and excellent machinability. With up to 95% fibre content, it supports brand owners aiming to reduce plastic use without compromising product safety or shelf appeal. Walki®Opti Seal is compatible with flexo, rotogravure and offset printing, offering wide creative freedom.
-
Walki®Opti Seal is designed with future recyclability requirements in mind under the EU Packaging and Packaging Waste Regulation (PPWR). Its minimised PE content supports efficient repulping and a high fibre yield. By reducing polymer use and enabling recycling within paper streams, brand owners can lower EPR fees, packaging taxes and CO₂ emissions while progressing towards fully circular packaging portfolios.

-
Walki®Opti Seal is ideal for both food and non-food flexible packaging, especially where a combination of strength, barrier protection and heat-sealability is required.
Common applications:
- Bakery goods and dried products
- Frozen food and ready-to-use mixes
- Home and personal care refills
- Industrial packaging
- Flow-packs (VFFS/HFFS), 4-side sealed sachets, overwraps

Walki Experts
In this Walki Experts episode, Karolina Lenart explains how Walki®Opti Seal helps brand owners reduce plastic use without compromising barrier performance or machinability. She walks through the science behind the optimised polymer layer, how it supports paper-stream recyclability, and why it performs so well on high-speed filling lines. Learn how this high-fibre solution delivers dependable sealing, strong mechanical properties and the circularity needed for future-proof flexible packaging.
What Makes Walki®Opti Seal Different
Walki’s monomaterial film solutions are engineered for circular performance at every stage. Built to meet PPWR standards, they use a true single-polymer structure designed for smooth recycling in standard PE systems. From high-barrier options to full in-house film and print capabilities, we deliver packaging that performs, protects and recycles the right way.
Sustainability Focus:
Designed for circular performance
Walki®Opti Seal is developed as a low-impact alternative to plastic laminates and traditional PE-coated papers. With up to 95 percent paper content, it is repulpable and designed for recycling according to industry guidelines such as 4evergreen. The functional polymer layer is down-gauged to only what is necessary, reducing plastic use at scale and enabling a strong fibre yield during recycling. Its efficient production and high machinability contribute to fewer rejects and resource savings across the value chain.
By combining pure polymer grades with strong kraft materials, Walki®Opti Seal ensures stable barrier performance and secure seals while remaining compatible with paper recycling systems. This gives brand owners a practical, ready-to-implement pathway to circularity, replacing multi-material packaging with a high-fibre alternative that fits future legislation and consumer expectations.
Reliable sealing and recyclability for frozen goods
How Walki®Opti Seal elevates frozen packaging
Frozen food consumption is growing rapidly across Europe, especially among millennials. To meet this demand without adding unnecessary waste, brand owners are turning to recyclable packaging solutions. Walki®Opti Seal plays a key role here, offering strong barrier performance, reliable sealing and paper-stream recyclability thanks to its optimised PE-coating.
In this article, learn how Walki®Opti Seal, Walki®EVO Seal, Lamibel®MDO-PE and Walki®Pack Tray help reduce waste while protecting product quality throughout freezing, transport and storage.
Comparison with mixed-material or non-recyclable solutions
| Walki®Opti Seal | Mixed-Material / Non-Recyclable | |
|---|---|---|
| Recyclability | Recyclable in paper streams | Not recyclable / difficult to separate |
| Material Content | Up to 95% fibre, minimal PE | Multi-layer paper/film or aluminium |
| Plastic Use | Controlled plastic content (≥5%) | High or multi-layered |
| Barrier Performance | Water vapour & grease protection | Often high, but with heavy polymers |
| Sealing | Reliable heat-sealing at low temperatures | Variable; higher energy needed |
| Machinability | Smooth on VFFS/HFFS lines | Smooth on VFFS/HFFS lines |
| PPWR Ready | PPWR-aligned, supports lower EPR fees | Increasingly restricted under PPWR |
Research & Development
Technology & Innovation Behind

Technical Competence Centres
Our in-house dispersion coating development at Walki’s Technical Competence Centres in Finland, Germany and Poland is redefining how barrier packaging performs. We’ve adapted materials used in papermaking to build a next-generation barrier portfolio. Walki®Opti Seal, designed with recyclability from the start.

Pioneering the future of fibre-based barrier production
At Walki, we’ve brought our next-generation production line to life. Designed entirely in-house and built to set new standards in sustainable barrier materials.
This state-of-the-art line integrates dispersion technologies, enabling us to produce high-barrier fibre-based materials with a low carbon footprint, without compromising recyclability. It’s a strategic expansion of our technology base, ensuring that our fibre-based solutions meet even the strictest future regulatory requirements.
The line responds to the fast-growing demand for recyclable, fibre-based alternatives. It marks a significant step forward in our ambition to deliver high-performance materials that support a circular economy.
Walki®Opti Seal is a fibre-based, heat-sealable packaging material with a down-gauged polymer coating. It offers strong barrier performance, high mechanical strength and excellent printability, all while remaining recyclable in paper streams.
The structure uses an optimised PE-layer that keeps polymer content to the minimum required for function. With up to 95% fibre content, it is repulpable and fits 4evergreen guidelines for paper-stream recyclability.
It is ideal for bakery, dried goods, frozen food, home and personal care items, and various industrial flow-pack formats such as VFFS, HFFS and sealed sachets.
By replacing paper/film laminates and high-polymer coatings with a thin PE-layer, Walki®Opti Seal significantly cuts plastic use while retaining essential barrier and sealing performance.
Yes. Its recyclability, high fibre content and reduced polymer layer support alignment with PPWR criteria, helping brand owners reduce EPR fees, CO₂ emissions and waste.
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