Bernhard Zimmer - Academia.edu (original) (raw)
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Douglas fir has been grown in Germany for over 100 years and is the most important exotic tree sp... more Douglas fir has been grown in Germany for over 100 years and is the most important exotic tree species in the country. At present it grows on 1.3% of the total forest area, with an expected increase to about 5% due to longterm silvicultural planning and age class distribution. This should entail a drastic rise in potential uses, especially in the field of wood from thinnings. Based on its anatomy and fibre morphology Douglas fir is, in principle, suitable as fibre raw material for the pulp and paper industry. However, as in pine, certain qualifications have to be made as regards heartwood extractives. These prevent pulping according to the sulfite process and are the cause for inferior optical characteristics in the production of mechanical pulp. Another drawback is the fact that heartwood formation in Douglas fir occurs very early between ages 3 to 12. Despite the above limitations Douglas fir, under certain conditions, appears suitable as raw material for thermo-mechanical pulps, ...
For the first time ever in Germany Douglas fir wood was pilot tested in industrial TMP production... more For the first time ever in Germany Douglas fir wood was pilot tested in industrial TMP production. The objective was to follow up comprehensive laboratory investigations by testing the suitability of Douglas fir wood for large-scale pulp production. A total of approx. 550 m 3 (about 118 t oven dry weight) Douglas fir from thinnings were converted into TMP. The quality of the resultant Douglas fir TMP was tested by approved chemical, technological and optical methods and compared with results for TMP manufactured from spruce. Special emphasis was placed on the characterization of the test material, tree age as well as annual ring width, increment, sapwood and heartwood portions. A direct comparison of the two tree species as regards TMP qualities and the interpretation of results was difficult due to overlapping effects based on the use of waste sawnwood on the one hand and roundwood from thinnings on the other. One disadvantage, apart from the deliberately high heartwood portion, wa...
Timber Construction Manual, 2004
Thermal treatments of wood (Fagus sylvatica and Fraxinus excelsior) were examined. The temperatur... more Thermal treatments of wood (Fagus sylvatica and Fraxinus excelsior) were examined. The temperature load on wood causes characteristic changes in the chemical composition, which were determined by means of several defined methods. The results confirm that in addition to the degradation of polyoses lignin, known as the thermally most stable compound, also shows significant thermal alterations. In addition, mechanical properties of the specimens were examined in order to correlate these results with the effects of chemical changes of thermally treated wood. It was shown, e.g., that the decomposition of the polyoses can affect the strength properties both positively and negatively.
Holz als Roh- und Werkstoff, 2004
Forest Products Journal
ABSTRACT
Holz als Roh- und Werkstoff, 2004
Holz als Roh- und Werkstoff, 1992
Nachhaltiges Bauen mit Holz - Zusammenfassung der Stärken des Baustoffes Holz unter ökologischen ... more Nachhaltiges Bauen mit Holz - Zusammenfassung der Stärken des Baustoffes Holz unter ökologischen Aspekten.
European Journal of Wood and Wood Products, 2009
Wood Science and Technology, 2012
ABSTRACT Quality assessment of thermally modified wood has evolved as one of the major fields in ... more ABSTRACT Quality assessment of thermally modified wood has evolved as one of the major fields in the research on thermal modification of wood. This study investigates NIR spectroscopy in combination with the pattern recognition method of soft independent modeling of class analogies (SIMCA). Focus is put on identifying different treatment intensities of thermally modified samples of beech, ash, and Norway spruce. The results indicate that SIMCA classification based on NIR spectroscopy could be used for quality control of thermally modified wood. The method might be applicable for producers (pre-delivery checks) and customers (reception control). However, transfer from laboratory to industrial conditions needs further investigation.
European Journal of Wood and Wood Products, 2009
Douglas fir has been grown in Germany for over 100 years and is the most important exotic tree sp... more Douglas fir has been grown in Germany for over 100 years and is the most important exotic tree species in the country. At present it grows on 1.3% of the total forest area, with an expected increase to about 5% due to longterm silvicultural planning and age class distribution. This should entail a drastic rise in potential uses, especially in the field of wood from thinnings. Based on its anatomy and fibre morphology Douglas fir is, in principle, suitable as fibre raw material for the pulp and paper industry. However, as in pine, certain qualifications have to be made as regards heartwood extractives. These prevent pulping according to the sulfite process and are the cause for inferior optical characteristics in the production of mechanical pulp. Another drawback is the fact that heartwood formation in Douglas fir occurs very early between ages 3 to 12. Despite the above limitations Douglas fir, under certain conditions, appears suitable as raw material for thermo-mechanical pulps, ...
For the first time ever in Germany Douglas fir wood was pilot tested in industrial TMP production... more For the first time ever in Germany Douglas fir wood was pilot tested in industrial TMP production. The objective was to follow up comprehensive laboratory investigations by testing the suitability of Douglas fir wood for large-scale pulp production. A total of approx. 550 m 3 (about 118 t oven dry weight) Douglas fir from thinnings were converted into TMP. The quality of the resultant Douglas fir TMP was tested by approved chemical, technological and optical methods and compared with results for TMP manufactured from spruce. Special emphasis was placed on the characterization of the test material, tree age as well as annual ring width, increment, sapwood and heartwood portions. A direct comparison of the two tree species as regards TMP qualities and the interpretation of results was difficult due to overlapping effects based on the use of waste sawnwood on the one hand and roundwood from thinnings on the other. One disadvantage, apart from the deliberately high heartwood portion, wa...
Timber Construction Manual, 2004
Thermal treatments of wood (Fagus sylvatica and Fraxinus excelsior) were examined. The temperatur... more Thermal treatments of wood (Fagus sylvatica and Fraxinus excelsior) were examined. The temperature load on wood causes characteristic changes in the chemical composition, which were determined by means of several defined methods. The results confirm that in addition to the degradation of polyoses lignin, known as the thermally most stable compound, also shows significant thermal alterations. In addition, mechanical properties of the specimens were examined in order to correlate these results with the effects of chemical changes of thermally treated wood. It was shown, e.g., that the decomposition of the polyoses can affect the strength properties both positively and negatively.
Holz als Roh- und Werkstoff, 2004
Forest Products Journal
ABSTRACT
Holz als Roh- und Werkstoff, 2004
Holz als Roh- und Werkstoff, 1992
Nachhaltiges Bauen mit Holz - Zusammenfassung der Stärken des Baustoffes Holz unter ökologischen ... more Nachhaltiges Bauen mit Holz - Zusammenfassung der Stärken des Baustoffes Holz unter ökologischen Aspekten.
European Journal of Wood and Wood Products, 2009
Wood Science and Technology, 2012
ABSTRACT Quality assessment of thermally modified wood has evolved as one of the major fields in ... more ABSTRACT Quality assessment of thermally modified wood has evolved as one of the major fields in the research on thermal modification of wood. This study investigates NIR spectroscopy in combination with the pattern recognition method of soft independent modeling of class analogies (SIMCA). Focus is put on identifying different treatment intensities of thermally modified samples of beech, ash, and Norway spruce. The results indicate that SIMCA classification based on NIR spectroscopy could be used for quality control of thermally modified wood. The method might be applicable for producers (pre-delivery checks) and customers (reception control). However, transfer from laboratory to industrial conditions needs further investigation.
European Journal of Wood and Wood Products, 2009