Windmöller & Hölscher is celebrating its 150th anniversary this year. As part of the celebrations, the German company has introduced a series of new products at K 2019, covering efficient production, sustainable packaging and digitalization.
In this interview, Torsten Schmitz, head of extrusion at W&H, highlights how each of these can be linked back to sustainability gains.
Q: W&H has launched the new Varex II blown film extruder with a new control interface. How does that help improve machine operation?
Schmitz: The film extrusion process looks easy, but there are several factors affecting the stability of the bubble. It’s very easy to break the material if the outer air pressure is too strong, if the plastic is too thin, or if the bubble is too hot.
The new Turbostart system can help with stopping and restarting the machine. Using this system, the machine can be up and running again in 10 minutes instead of 30. But a key feature of the new control screen is that in some instances it only has seven button choices. How can that control what could be hundreds of parameters?
The buttons don’t drive the machine; it’s process know-how. Before, you would switch on each extruder and then check if that was delivering the mix you wanted. Now, you can switch on all the extruders at the same time, based on the product.
It’s even more complex when you’re shutting down the system. We use a ramp curve that uses a linear decrease across operations, speed, air pressure. The machine stops and the bubble remains.
Q: What other new features does the Varex II incorporate?
Schmitz: This machine has a series of other new features, such as the automated cutting and opening of the bubble. This level of automation is unique to us, as is the Turbostart system.
Q: Customers are looking for improved sustainability. Was that the goal behind the Turbostart system?
Schmitz: Our vision for sustainable packaging production can be broken down into three elements. First, efficient production — that’s Turbostart and related systems. Second is sustainable product. Third is what we call Packaging 4.0 — the digitalization of the process.
Faster startup produces less scrap, but it’s more about full process control. That helps with delivering the product the customer has ordered.
Packaging 4.0 covers all details related to material recipe, other elements. A customer might have a product portfolio of 100 products which they make on a regular basis. We take those patterns for recognized products and the system ensures you’re making the right product.
Because the machine knows the product parameters, it can alert the operator when that production falls outside those limits, which helps in delivering the correct product.
Q: Can the Varex II machine support production of thinner films that some packaging manufacturers are interested in using?
Schmitz: Downgauging is a historical development which we’ve been investigating on an ongoing basis. Generally, the more sophisticated the resin, the more important it becomes to have a high-quality machine that can deliver the correct tolerances.
Along those lines, we have produced films using recycled materials; it’s just that the consumer wants plastics which are clear, look good. We have five-layer collation shrink products, one made from post-industrial and another using post-consumer waste.
It’s a great demonstration. I think the public should be aware that recycled plastic can look as good as plastic made from virgin material.
Q: Are these sustainable solutions developed by Windmöller & Hölscher, or together with a series of partners?
Schmitz: Looking at the larger picture, sustainable solutions can’t be created by just one company anymore. The “circular” element adds new stakeholders. Suddenly, you have to talk to people doing the collecting, the recyclers.
We have a new solution, an all-PE pouch. The sealing layer is conventional; the reclaimed material is there. We had to increase stiffness, without adding the PET layer.
Q: What’s the cost difference over the standard film this can replace?
Schmitz: It’s slightly higher. But that’s what the market has to accept when looking for a sustainable solution.
Q: The difficult part will be sourcing the recycled polymer to support production of this product?
Schmitz: Yes, it will. You’ll have to look at the recycling stream. In Germany, we have an advanced recycling network, but there is still room for improvement.
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