The University of Aveiro studies the properties of cork chipboard

José Pichel Andrés/DICYT The most common use given to cork is that of the manufacture of cork stoppers for bottles. However, this activity generates a large amount of cork waste that is made use of to produce chipboard, which has many applications. Researchers from the University of Aveiro are analysing the characteristics of cork chipboard and in particular how this material responds to different load or impact resistance conditions.

The objective of this study is “finding new applications for cork as a material and adding value to chipboard compounds", as DiCYT was told by Ricardo José Alves de Sousa, the scientist from the Department of Mechanical Engineering of the University of Aveiro who is directing this line of research.

Cork chipboard is produced from pure cork remains after the extraction of the cylindrical cork stoppers mainly used for wine bottles. These remains are separated according to their different grain sizes and are pressed until cork chipboard is obtained, for which polyurethane resin, for example, is used. In the case of expanded cork, a heating process is applied to the material and water is added to eliminate the need for using resin for the chipboard.

The researchers of the University of Aveiro are studying the static reactions and the dynamic reactions of cork, which are differentiated because for the latter impact situations are being tested. The university laboratories have the necessary machines for carrying out the static tests and a drop tower for carrying out the dynamic experiments.

In a recent publication in the scientific journal Material and Design, the researchers have shown that the mechanical properties of this product depend above all on the density of the chipboard and the size of the grain. For this reason the article highlights the great potential of this material for various applications related to resistance to impact. Moreover, it is also sustainable since it is a natural, biodegradable, and renewable material.

Very varied uses

Apart from cork stoppers for which cork chipboard is also suitable, this material can be used in the manufacture of very varied components in construction, jewellery, boats, and even surfboards. The researchers affirm that it is a "fashionable" material that is highly valued nowadays not only for its great versatility but also for its sustainability. The forthcoming objectives of the researchers are therefore the development of new cork products and compounds.

Cork is a plant tissue, the bark that covers the trunk of the cork oak (Quercus suber) and which grows each year. Over 60% of world cork production is concentrated in Portugal, which together with Spain accounts for over 90% of the market. This gives an idea of how extraordinarily important this product is to the Portuguese economy. “This is why there is so much interest in this kind of research; we have the support of companies of the sector in our search for new profitable applications”, Ricardo José Alves de Sousa emphasises.