Plasma technology for solvent-free wood preservatives

picture 1 wooden face_iris28.07.2010

Tags: wood preservatives, plasma technology, DURAWOOD

The DURAWOOD research project modifies wood surfaces so that wood preservatives adhere to them better and makes it difficult for harmful fungi to colonise the wood. So-called plasma technology is a highly promising approach. ttz Bremerhaven is evaluating the effectiveness of the process with a genetic detection method.

Bremerhaven, July 2010. In order to raise the competitiveness of wood compared to other materials, it is necessary to develop a cost-efficient method of wood protection which is free of toxic chemicals and nevertheless guarantees the wood's long durability. DURAWOOD (Development of a novel solvent-free coating process for wooden facades), a collaborative 2 years research project funded by the European Commission, has set itself the objective of developing a cost-effective, ecological, and high-performance method: the so-called DURAWOOD process uses electrical gas discharge (plasma) to treat wooden surfaces. The aim is to modify the surface characteristics of the wood so that wood preservatives can adhere to it better and thus smaller amounts of fungicide be needed.

So that wood is attractive for customers, it must be possible to guarantee the durability of treated wooden facades for at least 5 to 8 years without maintenance. New EU legislation (2004/42/EC) demands the replacement of solvent-based wood preservatives for exterior purposes. However, facades which have been treated with water-based preservatives are more susceptible to discolouring and damage from mould, blue-stain fungi, and other wood-decay fungi.

The aim is for a pre-treatment of the wood by means of plasma technology to improve the performance and durability of water-borne wood coatings.

Plasma technology modifies the wood surface

The plasma technology is based on applying the principle of electrical gas discharge where a so-called plasma is temporarily produced. The plasma is a gas or gas mixture which has been partly or fully ionised and thus contains free charge carriers such as ions, charged molecules or electrons. The plasma is produced with the aid of a DCSBD (Diffuse Coplanar Surface Barrier Discharge) electrode of the newest generation. The wood is transported past the electrode and treated continuously with plasma. The aim of the plasma treatment is to modify the characteristics of the wood surface, whereby two applications are used: on the one hand, the adhesion of coatings subsequently applied, such as water-based wood preservatives, is improved by means of a hydrophilisation of the wood surface, and on the other hand the wettability of the wood can be reduced by a marginal variation in the plasma parameters, as a result of which hydrophobic surfaces are produced which increase the water resistance of the wood. In the frame of the DURAWOOD project, the gas nature, concentration, treatment conditions will be optimized to design a new technique that will be easily implemented in industrial facilities handling wood.

Genetic detection method for mould

The DURAWOOD technology aims to facilitate a cost-efficient, durable, and environmentally friendly wood preservative and to strengthen the competitiveness of the European wood-processing industry. To test the efficiency of this new approach, the Molecular Genetics Department at ttz Bremerhaven is developing a rapid detection method for wood-decay fungi, with which the woods treated with the DURAWOOD process are being tested for their effective protection against fungi. For this purpose, pure cultures of the fungus being studied were incubated together with the wood either treated with DURAWOOD or untreated. The next step investigates how far the fungus has grown into the wood, using the highly sensitive Polymerase Chain Reaction (PCR) method, which is able to detect even only a few fungus cells.

About the project

The DURAWOOD project is funded under FP7 programme “Research for the benefit of SMEs” (Grant Agreement 232296). It involved 9 partners from 5 countries and is coordinated by Innovació i Recerca Industrial i Sostenible, Spain (IRIS). Research partners are: IRIS, ttz Bremerhaven (TTZ) and the Slovak University of Technology in Bratislava (STUBA). The consortium's industrial partners are composed on the one hand of the following wood-processing firms: Ing. Ján Šestina (SETA) from Slovakia, Kartas Kontrplak Sanayi Ticaret (KARTAS) from Turkey, and Aryecla S.L. (ARY) from Spain, and on the other hand of the following companies in the supply chain of the targeted technology: Plasma Technologic s.r.o. (PLASTECH) from the Czech Republic, which is specialised in plasma technology; PAM-ak s.r.o. (PAM-AK) from Slovakia and SETAS KIMYA SAN AS (SETAS) from Turkey are both manufacturers of wood, dye and powder coatings, respectively.

 

More information about this project can be found in the DURAWOOD project description.

 


Press pictures for editorial use (foto: ttz/pr)

picture 1 wooden face_iris

Picture 1:

In order to sustain the use of wood, the need exists for a cost-effective wood protection method free from toxic preservatives which is capable of offering a comparable performance and durability of solvent-borne coating. (Photo by IRIS)

picture 2 wooden terrace_redagainpatti_kl

Picture 2:

DURAWOOD will contribute to increase the competitiveness of wood products against newer materials. (Photo by redagainPatti on www.flickr.com)

picture 3 forest_batega

Picture 3:

DURAWOOD will enable the European wood industry to smoothly shift to a water-borne coating system for outdoor wood preservation. (Photo by Batega on www.flickr.com)

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ttz Bremerhaven regards itself as an innovative provider of research services and operates in the field of application-oriented research and development. Under the umbrella of ttz Bremerhaven, an international team of experts is working in the areas of food, environment, health and consulting services.