Article

Improved absorption characteristics of thermally modified beech veneer produced by plasma treatment

Holz als Roh- und Werkstoff (Impact Factor: 1.24). 09/2012; 70(5):545-549. DOI: 10.1007/s00107-011-0581-8

ABSTRACT

In this study the effect of an atmospheric pressure plasma treatment by a dielectric barrier discharge (DBD) on the wettability and absorption characteristics of thermally modified beech veneer is investigated. A common immersion test using water and melamine solution has been conducted and showed improved wettability and liquid uptake after plasma treatment. Determination of the weight percent gain (WPG) confirmed increased melamine content after plasma treatment.

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    • "Plasma processes may serve in improving the hydrophobicity and protection of surface materials (Drummond et al. 1997; Magalhães and Souza 2002; Bente et al. 2004) without changing the chemical structure of the bulk. Furthermore , hydrophilicity can also be improved (Avramidis et al. 2012; Tang et al. 2012; Zheng et al. 2012) through introduction of hydroxyl and carbonyl groups on a thin surface layer (Asandulesa et al. 2010). This approach is important for materials with roughened and irregular surfaces, such as MDF, which consequently have a low wettability and poor adhesion properties. "
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    ABSTRACT: Sample material from spruce (Picea abies), beech (Fagus sylvatica) and ash (Fraxinus excelsior) with radial and tangential section was treated by diffuse coplanar surface barrier discharge (DCSBD) plasma generated in air at atmospheric pressure. Plasma activated samples exhibited significantly lower water uptake times of 50 μl droplets and minimal differences in wetting between the two cutting planes (radial and tangential), when compared to the untreated surface. Simultaneously, more uniform spreading of the droplets and increased area of wetting on the activated surface were achieved. The plasma treatment had no effect on the water absorption coefficient of the wood samples. FTIR measurements confirmed the presence of oxygen containing functional groups and structural changes in lignin on the activated wood surface. The minimal heating of the treated samples suggests this method to be applicable to treat heat sensitive wooden materials.
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