Every day, something new happens

Manfred Diebold, Rolf Fehlbaum and Thomas Schweikert in conversation with Jochen Eisenbrand

The major exhibition ‘Plastic: Remaking Our World’ at the Vitra Design Museum in Weil am Rhein examines the history of the once revolutionary and now controversial material plastic. It serves as a platform for discussion about today’s use of plastics, the waste they generate and the new solutions that take into account the complete lifecycle of products and materials. The following interview appears in the exhibition catalogue.

Rolf, when you think back to the furniture production of the 1950s and ’60s, what feelings or memories do you associate with plastics?

Rolf Fehlbaum: A feeling of departure and optimism. The idea that one could shape this material in any which way—creating objects that we could have only dreamed of before—was very tempting. But it also harboured the danger noted by Charles Eames: that the ability to create anything would include the unnecessary, the arbitrary. The fact that plastic could have a problematic ecological effect never crossed our minds back then. It was quite simply a fantastic new material.

Plastics already played a role in the early days of the Vitra company.

Rolf: My father had an affinity with plastics. His shop-fitting business produced Perspex busts to present clothing on. Perspex could be shaped with very low-cost tools and without the use of complex machinery, simply by using heat. In 1952, Hans Theo Baumann and Vitra collaborated on a Perspex chair using this exact process. In actuality though, Perspex isn’t a very convenient material for the furniture sector; it attracts dust and scratches easily.

Manfred, you were involved in the development of plastic furniture at Vitra from the early 1960s. What led you there?

Manfred Diebold: I had done an apprenticeship at the Raymond company in the early 1950s, and they went on to employ me as a toolmaker. At some point, I was tasked with building the first tools for the production of plastic components for the automotive industry. I then changed jobs and started working at Stara-Werke in Lörrach, where we produced flower boxes and pots from Styrofoam. Among our commissions was one for decorative busts for Vitra, and that was my first point of contact with the company.

And so, you started working at Vitra in 1962.

Manfred: One of my earliest tasks was to establish our own Styrofoam production and also to help create a plastics production process. Vitra’s founder Willi Fehlbaum wanted to be as independent as possible from external suppliers. Little by little, we acquired all the necessary machinery for plastics production: an injection-moulding machine, an extruder, machines for deep drawing. Finally, we also got a large machine that could blow-mould entire mannequin bodies. Furniture production came later.

The collaboration Vitra established with Charles and Ray Eames was an important turning point in the company’s history. Here again, plastic, specifically fibreglass-reinforced polyester, played an important role.

Rolf: Fibreglass-reinforced polyester can be worked manually, as in the production of boat hulls, for example. Using the process that Charles Eames had developed together with Zenith, the Eames Chair shell could be produced in large numbers. The injection-moulding technology of the 1960s, using polypropylene, was another step towards industrialization. We had asked Charles if he’d design a polypropylene chair for us, but he didn’t seem interested. Since polypropylene doesn’t have the same structural properties as fibreglass-reinforced polyester, the dimensions of the side profiles of the seat shell would have needed to be a lot larger; Eames didn’t like that. He also appreciated the liveliness resulting from the somewhat irregular and easily visible glass fibres in fibreglass-reinforced polyester. Of course, this isn’t something you get with polypropylene.

Incidentally, I recently came across Paul Scheerbart’s book Glasarchitektur, and I found the following passage about glass fibres in applied art: “It has been forgotten by many that glass can be developed as fibres which can be spun. […] These glass fibres may lead to a whole new industry in applied art; divan covers, chair arms, etc., can be made of them.” Basically, he is talking about the kind of glass that we would then use for fibreglass much later. In 1914, Scheerbart urged the industry to rethink their practice: “The industry of the future will also turn eagerly to glass fibres. For only fire-resistant materials will be used – both for divans and for flooring, where glass fibres will prove the most important material.”

How was the technical know-how that was necessary in the production of the fibreglass shells transferred from the United States to Weil?

Manfred: Willi Fehlbaum’s negotiations with Herman Miller granted him the license to produce the Eames shells from fibreglass-reinforced polyester, after which I was sent to Zenith in Santa Monica to be mentored by Saul Fingerhut. There, I learned everything about how the production process worked and what we would have to pay attention to.

The first models of the Panton Chair, also developed at Vitra, were made from fibreglass-reinforced polyester as well.

Manfred: Indeed. However, unlike Eames, Panton did not want the material’s structure to be visible; the surface of the Panton Chair was to be perfectly smooth. We spent a year on the first model. Panton was a nocturnal worker and would always approach me after sunset, using lamps to light the model from all sides in order to detect any deformations or alterations. Even the first models that were presented in a 1967 edition of the magazine Mobilia were handmade samples made from fibreglass-reinforced polyester. My team included 25 people who had worked on mannequins, so we knew how to make things in a single mould. But still, the production was extremely time-consuming.

And then you discovered Baydur polyurethane as an alternative.

Manfred: Yes. We saw a car bonnet made from Baydur at the plastics fair in Düsseldorf, and Willi Fehlbaum asked me to visit Bayer to find out more. I explained our product idea for the Panton Chair, and I was told the reaction of the two components would have to take place in an aluminium or steel mould. In addition, the mould would need to be able to be heated and subsequently cooled down. Four weeks later, I’d built a plastic mould, and I drove back to Bayer. I had added some clamps for the mould to withstand the pressure, but when we injected the Baydur, we had to take cover – it went everywhere, the pressure was way too high! So, we cleaned the mould and then screwed it shut all the way around. With the second injection, it held, and we got a chair out of it that you could sit on. It was only then that Bayer realized what their material could actually do. We started producing the Panton Chair in series in 1968. However, each one still had to be sanded down, filled in, and then painted.

So, there was still a lot of handcrafting that went into it.

Manfred: Which begged the question of how to produce it in large numbers, because demand was really picking up. And then BASF approached us, saying: “We believe that we’re able to produce the chair through injection moulding with Luran.” We then produced a prototype, tested its stability, and finally decided to risk it, even though the ageing resistance of this particular polystyrene was unknown to us. This version was produced form 1971 onwards.

Due to the melt-in pigment of through-dyed Luran the Panton Chair no longer required a time-consuming handcrafted finish, which might indicate at least one of the motives for producing plastic chairs. Aside from the new design possibilities, the production costs are low, especially in large quantities.

Rolf: In this regard, Robin Day had made significant progress in the early 1960s with his chair for Hille. The shell was made by injection moulding polypropylene. As a consequence, it was very cheap and really stirred up the market. You could even say it marked the end of the Eames fibreglass chair as seating for the masses in halls and auditoriums. Another important development in the 1970s came with the all plastic chair, the Monobloc, produced from a single mould. I was fascinated by what this cheap chair had to offer: it can be quite comfortable, precisely because it is a little wobbly and flexible. But using the price point as the only guiding principle resulted in poor quality. The Monobloc became a chair that looks unsightly quickly and will end up in landfill rather sooner than later. Used in this way, plastics are problematic from an ecological standpoint, while products like the Eames Shell Chair or the Panton Chair – which remain in use over many decades – make the use of plastic more ecologically reasonable.

If we look at the role plastics play today in furniture production, there are entirely different challenges. Thomas, you are Technical Lead in Sustainability & Research at Vitra. How do you approach the topic of plastics?

Thomas: The first task for my team and I was to look into bioplastics. What propertiesdo bioplastics need to have? What would be desirable, and what are the exclusion criteria for their use? We carried out extensive research and developed an evaluation matrix which listed factors such as raw material, availability, price, recyclability, process capabilities, mechanical properties, and so on. Processability on a standard injection-moulding machine, for example, was rated highly, because significant investments would have to be made if that wasn’t possible. Colourability was rated lower down the scale, because bioplastics don’t have to look exactly like petroleum-based ones. We decided to exclude plastics that are made from food crops. And in this way, we gradually filled the matrix. When finally we evaluated it, we weren’t left with a single material that seemed suitable for long-lasting furniture components. Nevertheless, we decided to test three different materials in order to collect practical, experience-based data.

These were non-biodegradable materials, though: two types of polyethylene made from by-products of cane sugar processing and a polyamide made from castor oil. Unfortunately, the results weren’t satisfactory, and we decided to refrain from using bioplastics for the time being. What we learned from this experience though is that we should instead focus on circular economies and recycling, that is, keeping high-quality, petroleum-based plastics in the cycle for as long as possible.

How do differences in material quality play into this?

Thomas: Generally, we can say that the more diverse the source material of a recycled product is, the less possible it is for us to exactly define its properties. With many high-quality PIR [post-industrial recycled] grades, the primary material is almost completely pure, and so the properties of the resulting material are also quite stable. This becomes a little more difficult in the area of PCR [post-consumer recycled] grades. A valuable resource in Germany is the “yellow sack”, a bin bag that is used to collect plastic packaging. However, since these bags contain different types of plastics, they have to be sorted in the recycling process by type and ideally also by colour. Here, it’s crucial to work with the right companies that have mastered this process.

What does it mean that post-consumer recycled materials have to be compounded in order to be used in furniture production?

Thomas: The source plastic has to be optimized for the production process, and its properties must be altered in such a way that it can be used for durable and high-quality furniture components. During compounding, the regranulate is melted down, additives are mixed in, and it’s then granulated again. In this way, UV resistance as well as flow and mechanical properties can be improved, and the plastic can also be coloured to any desirable tone. Frequently, glass fibres are added to the plastic as well, to provide more stability and improve pressure resistance, tensile strength, and scratch resistance. In this way, we are able to realize significantly thinner sections with improved stability and even save plastic at the same time.

Do you still generate plastic waste during production?

Thomas: We are very conscious of our supply chains and want to ensure that no plastic goes to waste. Our manufacturers themselves even grind down flawed elements, overflows, or sprue parts and add the material to the next injection-moulding process. You can only do this to a certain extent, however, because the material can be damaged during the first moulding process. This is therefore only done to a small extent in components we produce that are subject to significant static loads. Anything that isn’t ground down is collected and handed over to a recycling company to be reprocessed, and then it re-enters the cycle.

Will plastic remain a useful material in the furniture sector in the future?

Thomas: We’re convinced that plastic as a material still has its place in furniture production. I think the question is rather one of how plastic is being used; it has to be done sensibly and responsibly. When I look at the Panton Chair or an EVO-C by Jasper Morrison, I see an extremely efficient way to produce well designed objects of outstanding quality at a reasonable price. One thing that will be of the essence in the future is to create a system and infrastructure that ensures any and all plastic products can be appropriately recycled and reused. Switching from a linear economy to a circular one is one of the most important challenges of our time. I really enjoy working in this area, because it is significantly dynamic. Every day, something new happens – so many new ideas, concepts, and technologies emerge… like a new beginning. I find being involved in this change very fulfilling, because the responsible use of plastics will continue to influence the designs of the future.

Publication date: 25.5.2022
Images: Jun Yasumoto, Vitra Corporate Archives, Vitra;

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