In the Spotlight: Philipp Sommerhuber

Mar 13, 2015

Philipp is working at the Thünen Institute of Wood Research in Germany.


The topic of your research project is Life Cycle Assessment of Wood-Plastic Composites. You’ve been working on it for some months now – how is your work progressing? What do you plan to do/cover over the next 6 months?

The research project and its title are quite broad, so I needed to specify research packages together with my supervisors at the Thünen Institute of Wood Research and University of Hamburg. This took a while but now I have a good structure for doing my PhD.

I would like to give you some background information for a better understanding of my research topic. In Germany and Europe, the predominant resources for Wood-Plastic Composites (WPC) are soft wood particles (spruce and pine) which are compounded with thermoplastics and additives in various contents. The downstream manufacturing processes of WPC after compounding are very heterogeneous. Extrusion and injection moulding are the two dominant production techniques for outdoor deckings, car door panels, and other consumer products. In Europe, the WPC market is prospected to further increase while the availability of soft wood will decrease what will lead to a rising price for wood particles. There exists also a strong competing demand for waste wood as a resource for thermal energy due to the Renewable Energy Directive (2009/28/EC) and material utilization in, for example, particle boards. On the other side, thermoplastics derived from fossil-based resources cause severe environmental impacts. Those competing issues make WPC very interesting from ecological and economic points of view alongside with the promotion of the European Bio economy. Therefore, the focus of my project is on the economic, technical, environmental, and social assessment of cascade use potentials of secondary resources for WPC.

So, I started with a literature review on how and which kind of WPC have been environmentally assessed up to now. The article is in the internal review process and will be soon submitted to a peer-reviewed journal. Meanwhile, I was preparing the experimental part of the research project. I set up contacts with local and regional recycling companies to be able to compare the mechanical and physical properties of WPC made from recycled wood and plastic particles to WPC made from virgin resources. 

The following images provide a better visual understanding of the experimental research: 1) On the recycling site, post-consumer wood products have been shredded to 2) wood particle size of 0 – 200 mm. 3) In our technical centre, the wood particles have been further processed to smaller particles 0 – 1 mm.  4) Virgin spruce particles have also been grinded to the same particle size 0 – 1 mm. In 5) and 6) the recycled post-consumer plastic HDPE and virgin HDPE are shown. Then, wood and plastic particles are compounded with various contents in a laboratory mixer and pressed to flat panels 7) – 10). The test specimen 11) are then physically and mechanically tested. For example, in 12) the flexural test according to ISO 178 is imaged.   

1)                                                                                2)


3)                                                                             4)


5)                                                                             6)


7)                                                                                 8)


9)                                                                                  10)


11)                                                                                 12)


Now, I am testing the mechanical properties (Tensile test, flexural test, Charpy impact test), physical properties (density, water absorption) and socio-technical properties (colour characterization) of the specimen. The results will be presented in a peer-reviewed research article in the next couple of months. Additionally, I will give an oral presentation at the 58th International Convention of the Society of Wood Science & Technology in Wyoming, USA in June. The convention is dedicated to renewable material science and the Bio-economy, which fits the overall CASTLE topic very well. I am also happy to meet my EAB supervisor Richard Bergman at the convention, so I hope this opportunity will benefit my further research on LCA of WPC.

Alongside the experimental and theoretical research, I conduct LCA of WPC window profiles, which are made from the same recycled resources that are used for the experimental part in my project. So, these tasks will cover the next months in the CASTLE project.         

In the near future, all results received from the different methods shall be rated by means of a Multi Criteria Analysis (MCA) to obtain thorough answers to the research questions.  Moreover, there are lots of potentials for further research and publishing. Possible further research topics could be the investigation of the feasibility of using bio refinery products, post-consumer harvested timber products, bioplastics, other recycled thermoplastics or elastomers and thermosets for WPC. Time is short, so my aim is to focus on recycled polyethylene and post-consumer wood products and develop an environmental product design method that can be used for WPC but is also applicable for very different materials and products.

Why did this exact topic interest you?

Beside the great work and travelling possibilities the CASTLE project and its partners provide in the Marie Curie ITN environment, the CASTLE project fits perfectly to my education, my previous work experience, and my personal interests. I wanted to intensify my knowledge about material science. So having the opportunity to work with wood scientists at the Thünen Institute of Wood Research, to deepen my knowledge in LCA and to do a PhD at the same time was an irresistible offer.

Furthermore, we live in a society that is able and willing to invest in research and set the course to become a sustainable and resource efficient society, which will benefit the economic, environmental, and social pillars of the European Union’s economy. With my project, I hope to be able to contribute to open questions in the fields of:

  • Cascade use of resources and products

  • Sustainable economic growth

  • Decision making processes which include economic, technical, environmental and social aspects

So I was and I am still very much excited about my research topic. Furthermore, I am quite confident about a steadily growing interest for environmental indicators and the use of recycled resources for any consumer products in our society. 

What would you like to do after the CASTLE project has finished?

Efficient use of resources, valorisation of waste resources, sustainable growth, and environmental design of products are topics that are on the one side contemporary for the European society and on the other side topics, I want to deal with further on. My research project has become both experimental and theoretical which is a perfect blend in my opinion and challenges me every day. As I have experienced different kinds of jobs up to now, I have learnt that I need challenges to find joy in my work for the long term perspective, even though challenges can be frustrating in the short term. So my wish for my future career is that it shall be a perfect blend of challenges, joy and the chance to make a contribution towards a more sustainable society.

What are your thoughts on the CASTLE project so far, and the training courses in particular?

First, I would like to say that the CASTLE project with its funding scheme for my PhD is a once in my lifetime opportunity, for which I am very grateful. The CASTLE project helped me a lot to focus on my interests and broadened my knowledge in an international and interdisciplinary scientific environment.  Concerning the training courses in particular, it felt a little bit like the first years at school or university where different methods and skills are introduced. However, I noticed quickly that the lessons and meetings will help me to understand my project and see the linkages to the topics of the other ESRs, so that we all can benefit from one another’s research. The discussions during the workshops make the lessons very lively and open minded which is great.   

Finally, I am looking forward to the CASTLE conference in Barcelona in October 2015, where we will meet researchers, policy makers, and industrial experts. The combination of the overall CASTLE topic, workshops, and interaction with people is what makes this Marie Curie ITN so unique.