Science

Delft PhD student tries to bring circular economy a step closer

A promising way of reducing the flows of resources in and out of the system is circular economy. Dr Marcel den Hollander has created new tools to help designers create long-lasting products that will help keep the resources in the loop.

Marcel den Hollander (front row, third from the left) after receiving his doctorate. (Photo: Marcel den Hollander)

Why circular economy?

“In a linear system, there is an input of raw materials and an output of waste. Since the industrial revolution, this flow has increased to a point where it has become critical from both an environmental and an economic point of view. Circular economy is a promising way of keeping the resources within the economic system to a level that is naturally indefinitely sustainable while preserving the capacity to create wealth.”


How do you keep resources in the system?

“My research focuses on preserving the materials by extending the lifetime of the products. When a product’s life comes to an end the materials can be recycled for environmental and/or economic reasons.”


When does a product’s life end?

“Normally, a product’s lifetime is defined in terms of functionality, but literature shows that many products that are still functional are discarded for other reasons, for example if a new model appears on the market. I redefined product lifetime in terms of obsolescence, that is whether a product is still wanted by its user or not. Companies can extend the lifetime of products by taking control over the flow of obsolete products, recovering them and reintroducing them on the market at predetermined moments.”


Is it possible for a business to recover a product once it is out on the market?

“My premise is that users will give industries permission to take back the products if they see the benefits. For example, if you get a discount on a new phone by giving back your old one you will probably do it. Businesses that retain ownership of a product and rent it instead of selling it, can control the flow of products much more easily.”


Postcards survive for decades because people find an emotional value in them


Can a designer actively help a business control this flow by designing a product in a specific way?

“To ‘manage obsolescence’, a designer has to control not only the product’s spatial dimension (size, material, colour) but the temporal dimension too. The designer predicts the journey of a product from when it is newly manufactured to the end of its life, and decides on the best steps to extend its life as far as possible. For example, when should a manufacturer recover a product and what needs to be done to it before reintroducing it to the market. The business context in which the product is embedded is also taken into account.”


How do you make sure a product will have the longest life possible?

“There are three directions. You can design a product focusing on its durability, both physical and emotional. For example, postcards are made of paper, so they can burn, tear and become mouldy. But they survive for decades because people find an emotional value in them. Secondly, you can extend the lifetime of a product by making sure it can be maintained, repaired or upgraded. And finally, you can make a product last longer by changing its context. For example, a phone that is no longer used by one person can have a new life in the hands of another person, even if it means repairing or remanufacturing the product in the process.”


What should you consider when deciding on the direction?

“First, the product type. Will it be sold or rented? How often will it be used? Another factor you have to consider is the lifecycle stage of a product category. For example, if you are designing a washing machine you can concentrate on the durability because changes in the technology are marginal. However, if you are designing a new and evolving product, like 3D printers, your approach should be different. Instead of focusing on durability you should focus on upgrading, making sure you will be able to recover the machine and change its components at some point. There are also cultural preferences you should consider.” 


Why not rework obsolete products into something valuable?


Should all products have a long life?

“No, sometimes extending the life of a product can cause more problems than benefits. Syringe needles are a good example of this. We need to look into every specific situation and find the balance. For single use products we need to make the recycling process easy by ensuring that materials can be easily separated and reused.”


Why would a business invest in creating long-life products?

“Spending time and money on extracting resources from under the ground and then discarding them might not be the most effective way to generate business revenue. When disposing obsolete products becomes a cost factor, why not rework them into something valuable?” 


What kind of businesses can profit from producing long-lasting goods?

“There are classic business models that can sell their products at higher prices because durability is an added value. There are other businesses that rent their products or sell the services derived from them instead, like laundry companies for example. They also benefit if their products have an extended life. Other types of businesses profit indirectly from long-life products. For example, if Nespresso sells long-lasting coffee machines they will profit from selling capsules for a long time.” 


Is it possible to achieve a perfectly closed loop in the circular economy?

“I don’t think complete closure is possible although we might get very close. There is always ‘leakage’: when I walk I lose the rubber on my soles that I can never get back. There are also mixtures of materials that we cannot separate with the current technologies, but instead of burning or burying these materials, we could for example store them until we are able to separate them.”


Have your models been tested and your tools been used by designers?

“This is a conceptual proposal and it has not yet been tested. The most important goal was to not make the final prediction model, but to point towards a potential solution and highlight the need for additional research. I have created a design methodology and framework, now we need empirical research to make this model more reliable and validate it or reject it.”


Marcel den Hollander, Design for Managing Obsolescence. A Design Methodology for Preserving Product Integrity in a Circular Economy, PhD supervisors Conny Bakker and Erik Jan Hultink, 15 June 2018


Maria Rubal / science editor

Editor Redactie

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