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P. 34
tinuous densification of solid wood
The band press approach
Benedikt Neyses1, Dick Sandberg2
1 Luleå University of Technology, benedikt.neyses@ltu.se
2 Luleå University of Technology, dick.sandberg@ltu.se
The densification, i.e. transverse compression of solid wood can lead to improvements in the
mechanical properties, and this opens up new applications for low-density wood species, in
particular. For the past one hundred years, many efforts have been made to mass produce
densified wood products, but despite being available on the market, they still are niche products
with annual production volumes of about 2000 m3 in Europe.
Hitherto, all commercially available densified wood products have been produced in a batch-type
process, which limits the achievable process speed and integration into the largely continuous
wood processing chain. In two previous studies, we explored a continuous surface densification
approach using roller pressing equipment. Desired density profiles with a pronounced peak
close to the surface could be obtained at process speeds of up to 20 m min-1. However, the
short contact time between the wood and the rollers makes it virtually impossible to integrate a
cooling stage and treatments to reduce the set-recovery into the process.
For these reasons, we propose the use of a band (belt) press. Such a machine will be installed
in the Wood Science and Engineering division at Luleå University of Technology in the first
quarter of 2020, and will function as a research and process development platform. The press
is dimensioned for the densification of full-sized floor boards of up to 250 mm in width and
100 mm in thickness, at a processing speed of up to 60 m min-1. It is equipped with sensors
to measure the pressing forces, moments, and temperature, and its design allows for digital
image correlation analysis of the densification process. We hope that the new band press will
push densified wood products closer to large-scale industrial implementation and foster new
collaborations with other research groups in the field of wood densification
.
Keywords: wood compression, densification process, belt press, process development
Acknowledgements: Financial support from the Frans och Carl Kempes Minnestiftelse 1984
and the CT Wood Centre of Excellence at the Luleå University of Technology is gratefully
acknowledged.
INNORENEW COE INTERNATIONAL CONFERENCE 2020
34
The band press approach
Benedikt Neyses1, Dick Sandberg2
1 Luleå University of Technology, benedikt.neyses@ltu.se
2 Luleå University of Technology, dick.sandberg@ltu.se
The densification, i.e. transverse compression of solid wood can lead to improvements in the
mechanical properties, and this opens up new applications for low-density wood species, in
particular. For the past one hundred years, many efforts have been made to mass produce
densified wood products, but despite being available on the market, they still are niche products
with annual production volumes of about 2000 m3 in Europe.
Hitherto, all commercially available densified wood products have been produced in a batch-type
process, which limits the achievable process speed and integration into the largely continuous
wood processing chain. In two previous studies, we explored a continuous surface densification
approach using roller pressing equipment. Desired density profiles with a pronounced peak
close to the surface could be obtained at process speeds of up to 20 m min-1. However, the
short contact time between the wood and the rollers makes it virtually impossible to integrate a
cooling stage and treatments to reduce the set-recovery into the process.
For these reasons, we propose the use of a band (belt) press. Such a machine will be installed
in the Wood Science and Engineering division at Luleå University of Technology in the first
quarter of 2020, and will function as a research and process development platform. The press
is dimensioned for the densification of full-sized floor boards of up to 250 mm in width and
100 mm in thickness, at a processing speed of up to 60 m min-1. It is equipped with sensors
to measure the pressing forces, moments, and temperature, and its design allows for digital
image correlation analysis of the densification process. We hope that the new band press will
push densified wood products closer to large-scale industrial implementation and foster new
collaborations with other research groups in the field of wood densification
.
Keywords: wood compression, densification process, belt press, process development
Acknowledgements: Financial support from the Frans och Carl Kempes Minnestiftelse 1984
and the CT Wood Centre of Excellence at the Luleå University of Technology is gratefully
acknowledged.
INNORENEW COE INTERNATIONAL CONFERENCE 2020
34
