Our machines regularly have their say: today we are talking about a blown film line that has been in operation at Hof University of Applied Sciences since 2016. It is supervised by Tobias Gareiß, technical laboratory employee and Prof. Michael Nase, Scientific Director of the Institute for Circular Economy at Bio:Polymers.
Who are you? Please introduce yourself briefly.
“I’m a foil plant, I don’t really have any other name. I’ve been here since December 2016 and have moved around the machine hall many times since then – by the way, I move around in a similar way to all the other employees. I’m currently in room C017.”
What does a blown film line do, can you explain it to us in more detail?
“I produce film from plastic granulate. This means that my hopper is filled with plastic granulate and a few additives. The whole thing is then melted, homogenized and plasticized. The molten plastic is then transported to the blowing head, i.e. the extrusion tool, and pressed into the blowing head through the ring nozzle. This creates a bubble by blowing in air – just like chewing gum. This bubble is then flattened directly at the tip of the blowing tower. The edges of the bubble are then cut off. And then you have two flat sheets of foil that you can wind up neatly. As this is a bit more complicated, I only let specialists do it.”
What is your most important component?
“Without question, the extruder, because without it, no plastic can be melted.”
And what are you particularly good at?
“I can produce film, single or multi-layer. I can also test plastic material and of course – very importantly – I can also be a demonstration object for practical courses.”
How did you come to the university? Who bought you?
“I am a second-hand donation in kind from POLIFILM Extrusion GmbH – Michael Nase’s former employer. I’m very proud that I was the first film line at the university. Today there are a few more of us – which shows how important we are. We still talk about my stepsister, for example.”
Are you more involved in research or in helping students so that they can learn something from you?
“Both: I’m involved in numerous research projects that aim to develop a slide, but also in various internships. I am also regularly involved in recruiting young talent and can be seen in action at Girls Day, Girls and Technology Day, the Open Day or visiting school classes. Children and guests can learn a lot from me, because I am quite transparent, i.e. you can look into me from the outside and see and follow the whole process of creating films.”
What about sustainability? Have your films become thinner and thinner? Which materials were used in the past and which are used today?
“Over the years, my films have become thinner and thinner, yes. That reduces material costs. However, recyclability becomes very difficult above a certain thickness or thinness. Recently, I have also been allowed to process bioplastics such as PLA (polylactic acid), TPS (thermoplastic starch), PBAT (polybutylene adipate terephthalate), PBS (polybutylene succinate) and PHB (polyhydroxybutyrate). I really enjoy bioplastics, but conventional plastics are easier.
I can also summarize it like this: A big important area for us is films that might end up in nature one day and are supposed to decompose there. That would be agristretch films or organic mulch films, for example. A second area is short-life packaging. We want this to be made much more from biodegradable biopolymers than before. One example of this is cool packs, which are often simply left lying around at large concerts.”
What do the students and researchers do with you?
“The students treat me really well. They are attentive, they try things out and talk me through it. They are very careful at the beginning in particular, but then they try out more. Nothing has ever broken. Quite the opposite of the researchers: They’re sometimes in a hurry and then something breaks. I can’t always keep up with that in my old age.”
It would be better if ...
“… i would get support from a new, more innovative, technically better extruder. If anyone reading this happens to have a 25x30D or 30x30D extruder for us, please get in touch with Michael Nase. He would be very happy.”
Are you happy at Hof University of Applied Sciences? If you could wish for something, what would it be?
“Yes, I’m very happy here and occasionally enjoy annoying the researchers and technicians. As I still have to work at the university for a long time, I would like to have new machine components, as I just said.”
Where have your brothers and sisters ended up?
“My stepsister, the cast film line, is close to me. She makes so-called “cast films” for the BioSlide project, for example. It’s about sliding surfaces for skiing and water sports, so not inflatable like mine, but rather a layer of film.”
You have no eyes, so …..
“… it would of course be great if I could get an additional error detection system to improve the quality of the film. Or even a thickness gauge or a stipple counter that can tell me how many defects my film has if, for example, a fly has been included. Because the fact is: as I’m so old, I’ve already had a lot of things replaced and extended, so the Nase and Gareiß team have a lot of experience with that.”
How long do you expect to stay here in the machine hall?
“Until the bitter end!”
Thank you very much for the interview!
