Home-blown
Rob Coker introduced himself to Zdenek Vanek, the CEO of Czech Republic-based VBF (Vanek Bayer Formy) blow mould production, at Interplas 2021.
I tried to focus as much as possible on connecting with Europe-based exhibitors during Interplas 2021 and was therefore pleased to introduce myself to the experts at the small but neat VBF booth after recognising the moulds and products for the blow moulding sector. After the traditional exchange of business cards, Vanek began by explaining the intricacy involved in a mould used by Krones for beverage packaging. The bottle itself had a detailed, crystalline, glass-like appearance. “A lot of time went into designing it,” Vanek said. “I can’t tell you an exact number, but it is a lot of time. The surface is then hand-polished, so that will add some more time, depending on the complexity of the mould.”
The same level of skill is of course required to create less intricate moulds, but the approach is always the same. VBF would first design and then machine the mould in several stages, including the in-mould labelling stage, which forms part of the design of the mould and is performed by the machine. “It's all automated,” Vanek continued, “this is not really possible to produce manually. The machines work with high levels of precision, which allows us to go into such detail even with the carvings.” Finally, each mould is hand-polished to bring out the finish and detail.
Vanek then pointed out what he described as an “interesting piece” – a hose used in the automotive sector. The plastic, polypropylene with ethylene propylene diene monomer (EPDM), is graded for high temperatures, making it suitable for gases that pass through turbochargers. “The manufacturing method is quite interesting,” Vanek continued. “Because of its intricate shape, it requires a combination of vacuum moulding and blow moulding. It starts with a prefabricated plastic piece and vacuum moulding is used to extrude it to create the basic shape. Air is then pumped into the cavity and it expands to form the final shape.”
Blow moulding is most often associated with packaging plastics such as PET and so it was interesting to have been reminded that almost any plastic can be blow moulded. “It depends on the application,” Vanek confirmed. “Different plastics have different properties. You wouldn’t necessarily use the same plastics for injection moulding, but there is a wide variety of materials used for blow moulding, including PS, PP, PE, and PET. We manufacture moulds for multiple materials.”
Continuing with blow moulding for the automotive sector, Vanek produced an example of a technical mould. “It's within our capabilities to manufacture moulds up to two-by-two metres – so, fairly big chunks of metal. This example was manufactured for a company that supplies the final product to almost all large European car manufacturers, such as Škoda, VW, BMW, etc. They use this particular mould to make air ducts for Mercedes and you can manufacture up to four parts in it.”
There is a Mercedes in my household – not mine, I should add, but I do drive it at weekends – so it was fascinating to learn that some of VBF’s expertise is included in it. We tend not to notice and take for granted such parts in our vehicles until you meet the person manufacturing them. “I think
this is one of the things about blow moulding,” Vanek added. “It's quite niche. The majority of industries obviously use injection moulding, but anything that has a cavity in it was likely blow moulded. It's always quite interesting to see when I go into a supermarket and see a bottle that our company supplied blow moulds for.”
VBF will also be exhibiting at K 2022.