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The effect of process parameters on the hardness of surface densified Scots pine solid wood

Einfluss von Prozessparametern auf die Härte von oberflächenverdichtetem Kiefernmassivholz

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This paper addresses the effect of surface densification on the Brinell hardness of Scots pine sapwood. Densification was performed in an open system under heat and compression using different compression temperatures and closing times. The hardness was measured using a modified Brinell hardness method. Furthermore, the density profiles of the samples were measured and their correlation to hardness analysed. It was found that the process parameters strongly affected the hardness of surface densified solid wood. This knowledge is relevant when optimising the densification process according to the properties required of the end-product. At 150 °C compression temperature and 0.5 min closing time, the average Brinell hardness (23.4 N/mm2) was double to that at 200 °C and 5 min closing time (11.6 N/mm2).


In dieser Studie wird der Einfluss einer Oberflächenverdichtung auf die Brinell Härte von Kiefernsplintholz untersucht. Die Prüfkörper wurden in einem offenen System unter Wärme und Druckbeanspruchung bei verschiedenen Temperaturen und Schließzeiten verdichtet. Die Härte wurde anhand eines modifizierten Verfahrens zur Bestimmung der Brinell Härte ermittelt. Darüber hinaus wurden die Dichteprofile der Prüfkörper bestimmt und ihre Korrelation mit der Härte untersucht. Es wurde gezeigt, dass die Prozessparameter einen starken Einfluss auf die Härte von oberflächenverdichtetem Massivholz haben. Diese Erkenntnis kommt zum Tragen, wenn der Prozess entsprechend der gewünschten Eigenschaften des Endprodukts optimiert werden soll. Bei einer Presstemperatur von 150 °C und einer Schließzeit von 0,5 min war die mittlere Brinell Härte (23,4 N/mm²) doppelt so hoch wie bei einer Temperatur von 200 °C und einer Schließzeit von 5 min (11,6 N/mm²).

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The researchers would like to acknowledge Mr. Nick Laflin of the BioComposites Centre, Bangor University, UK and Miss Cara Leitch for technical support in this study.

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Correspondence to Kristiina Laine.

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Laine, K., Rautkari, L. & Hughes, M. The effect of process parameters on the hardness of surface densified Scots pine solid wood. Eur. J. Wood Prod. 71, 13–16 (2013).

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