At extrusion coating process a thin layer of polymer is applied onto a base, typically fibre-based paper. Extrusion coating makes packaging more durable and resistant to all sorts of damage. At KCL, we’re using cutting-edge 5-layer coextrusion technology to lead the charge in creating sustainable and high-performance packaging solutions.
Getting to Know Extrusion Coating
A molten layer of material, usually a polymer, is spread over a base to form a composite structure. This is what extrusion coating is all about. It’s a go-to method in the packaging world, ensuring your products stay safe and sound during their journey to you. The beauty of this process is its flexibility. Whether it’s paper, foil, or plastic films, we can tailor the coating to meet specific needs.
In today’s world, where sustainability is key, extrusion coating is important. By using biodegradable or recyclable polymers, we can create packaging that not only protects but also respects our planet.
How Does Extrusion Coating Work?
Process starts with melting a polymer resin, which is extruded through a flat die to form a thin film. This film is applied to a moving base, which is prepared to ensure it sticks well. Once cooled, you’ve got a tough, composite material ready to go.
Key factors like coat weight, adhesion, and neck-in evaluation are crucial here. Coat weight is all about getting the thickness just right. Adhesion ensures the coating stays put, and neck-in evaluation checks the film’s width consistency. It’s a bit technical, but these details make all the difference.
Why Choose Extrusion Coating for Packaging?
Extrusion coating enables superior high barrier packaging. Extrusion coating creates a strong barrier against moisture and oxygen, which is vital for keeping food and pharmaceuticals fresh. Plus, it makes packaging tougher, so it can withstand the bumps and knocks of transport. And with options for surface treatments like flame or plasma, the performance just gets better.
Extrusion Coating vs. Extrusion Lamination
While often confused, extrusion coating and extrusion lamination are distinct processes with different applications. In extrusion coating, molten polymer is applied directly onto a single substrate (typically paper or paperboard) as a protective or barrier layer. The polymer forms a coating that shields the substrate from moisture, oxygen, and other elements.
Extrusion lamination, on the other hand, uses the molten polymer as an adhesive layer between two substrates. The polymer essentially acts as a bonding agent, creating a multi-layer structure with different materials sandwiched together.
| Characteristic | Extrusion Coating | Extrusion Lamination |
|---|---|---|
| Function | Polymer serves as protective/barrier layer | Polymer serves as adhesive between substrates |
| Substrate Requirements | Single substrate (often paper-based) | Two or more substrates (can be different materials) |
| Typical Applications | Liquid packaging, moisture barriers, grease-resistant packaging | Food pouches, multi-layer industrial packaging, packaging requiring different properties in each layer |
| Processing Considerations | Requires substrate pretreatment for adhesion; focuses on surface properties | Requires precise temperature control to ensure proper bonding between layers |
At KCL, our expertise allows us to optimize both processes based on your specific packaging requirements. Understanding this distinction is crucial when selecting the most appropriate technology for your application, as it impacts material selection, production efficiency, and final product performance.
Innovative Uses of Extrusion Coating
From flexible pouches to industrial wraps, extrusion coating is everywhere. Its versatility means it can cater to both consumer and industrial needs. At KCL, our advanced technology allows us to create multi-functional packaging with superior barrier properties. Imagine combining different polymers to achieve heat resistance or chemical stability. That’s the power of our 5-layer coextrusion technology.
How Does It Compare to Other Methods?
So, how does extrusion coating stack up against other methods like lamination or solvent-based coatings? Unlike lamination, which uses adhesives to bond layers, extrusion coating applies a single, seamless layer directly. This results in a more uniform finish. And when it comes to being eco-friendly, extrusion coating wins hands down. It doesn’t rely on volatile organic compounds, making it a greener choice.
Extrusion Coating and Sustainability
Extrusion coating is a champion for sustainable packaging. By choosing the right polymers like biodegradable biopolymers, we can make packaging that’s easier to recycle or compost. Plus, the process itself is energy-efficient with minimal waste. It’s a win-win for the environment and the industry.
What’s Next for Extrusion Coating?
The future looks bright for extrusion coating, with new materials and technologies on the horizon. Innovations in biodegradable polymers and nanocomposites promise to boost performance and sustainability. At KCL, our pilot line, running at a speedy ~400 m/min with a 500 mm width, is where we test and inmprove these new materials. We ensure they meet the highest standards, from sealability to pinhole resistance.