---
_id: '11792'
abstract:
- lang: eng
text: To facilitate the drying process and enhance the properties of oil palm wood,
oil palm boards were mechanically pre-dewatered and thermo-hygro-mechanically
(THM) densified. The thickness of the boards was reduced with compression ratios
of 40%, 60% and 75%. Since densified wood tends to recover from compression, especially
under humid conditions, this study examined the set-recovery and the hygroscopic
behavior of THM densified oil palm wood. The equilibrium moisture content (EMC),
differential swelling and swelling coefficient, linear swelling and shrinkage
as well as the differential swelling anisotropy were determined under climate
conditions with different relative humidity (RH) (20°C/35% RH, 20°C/65% RH and
20°C/85% RH). The maximum swelling was measured after water soaking and the remaining
set-recovery was evaluated after re-drying at 103°C. The EMC was reduced by the
THM process by around 20%. In the direction of compression (thickness), the densified
specimens show higher values for all analyzed swelling and shrinkage parameters
than the undensified specimens from the equivalent position within the trunk.
The maximum swelling in thickness of 22–38% during water soaking is mostly reversed
by shrinkage during re-drying and a comparably low remaining set-recovery of 3–8%
is measured at oven dry condition.
author:
- first_name: Nathan
full_name: Kölli, Nathan
id: '74242'
last_name: Kölli
- first_name: Katja
full_name: Frühwald-König, Katja
id: '26232'
last_name: Frühwald-König
- first_name: Martin
full_name: Hackel, Martin
id: '79798'
last_name: Hackel
citation:
ama: Kölli N, Frühwald-König K, Hackel M. Hygroscopic behavior of thermo-hygro-mechanical
(THM) densified oil palm sawn timber. Wood Material Science & Engineering.
Published online 2024:1-12. doi:10.1080/17480272.2024.2381100
apa: Kölli, N., Frühwald-König, K., & Hackel, M. (2024). Hygroscopic behavior
of thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood Material
Science & Engineering, 1–12. https://doi.org/10.1080/17480272.2024.2381100
bjps: Kölli N, Frühwald-König K and Hackel M (2024) Hygroscopic Behavior
of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber. Wood Material
Science & Engineering 1–12.
chicago: Kölli, Nathan, Katja Frühwald-König, and Martin Hackel. “Hygroscopic Behavior
of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” Wood Material
Science & Engineering, 2024, 1–12. https://doi.org/10.1080/17480272.2024.2381100.
chicago-de: 'Kölli, Nathan, Katja Frühwald-König und Martin Hackel. 2024. Hygroscopic
behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood
Material Science & Engineering: 1–12. doi:10.1080/17480272.2024.2381100,
.'
din1505-2-1: 'Kölli, Nathan ; Frühwald-König, Katja ; Hackel,
Martin: Hygroscopic behavior of thermo-hygro-mechanical (THM) densified
oil palm sawn timber. In: Wood Material Science & Engineering. London,
Taylor & Francis (2024), S. 1–12'
havard: N. Kölli, K. Frühwald-König, M. Hackel, Hygroscopic behavior of thermo-hygro-mechanical
(THM) densified oil palm sawn timber, Wood Material Science & Engineering.
(2024) 1–12.
ieee: 'N. Kölli, K. Frühwald-König, and M. Hackel, “Hygroscopic behavior of thermo-hygro-mechanical
(THM) densified oil palm sawn timber,” Wood Material Science & Engineering,
pp. 1–12, 2024, doi: 10.1080/17480272.2024.2381100.'
mla: Kölli, Nathan, et al. “Hygroscopic Behavior of Thermo-Hygro-Mechanical (THM)
Densified Oil Palm Sawn Timber.” Wood Material Science & Engineering,
2024, pp. 1–12, https://doi.org/10.1080/17480272.2024.2381100.
short: N. Kölli, K. Frühwald-König, M. Hackel, Wood Material Science & Engineering
(2024) 1–12.
ufg: 'Kölli, Nathan/Frühwald-König, Katja/Hackel, Martin: Hygroscopic behavior
of thermo-hygro-mechanical (THM) densified oil palm sawn timber, in: Wood Material
Science & Engineering (2024), S. 1–12.'
van: Kölli N, Frühwald-König K, Hackel M. Hygroscopic behavior of thermo-hygro-mechanical
(THM) densified oil palm sawn timber. Wood Material Science & Engineering.
2024;1–12.
date_created: 2024-07-27T05:38:16Z
date_updated: 2025-06-25T13:03:03Z
department:
- _id: DEP7018
- _id: DEP1309
doi: 10.1080/17480272.2024.2381100
external_id:
isi:
- '001274838600001'
isi: '1'
keyword:
- Densification
- set-recovery
- swelling and shrinkage
language:
- iso: eng
page: 1-12
place: London
publication: Wood Material Science & Engineering
publication_identifier:
eissn:
- 1748-0280
issn:
- 1748-0272
publication_status: published
publisher: Taylor & Francis
quality_controlled: '1'
status: public
title: Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn
timber
type: scientific_journal_article
user_id: '83781'
year: '2024'
...
---
_id: '11114'
abstract:
- lang: eng
text: Oil palm wood is mainly low in density and since strength and stiffness correlate
with density, this study aimed to enhance the properties of oil palm wood through
thermo-hygro-mechanical (THM) densification. In contrast to other studies using
small laboratory-sized specimens, this study examined the densification of oil
palm boards in sawn timber dimensions of 2.0 m length. Modulus of elasticity (MOE)
and modulus of rupture (MOR) in bending, shear strength and shear modulus parallel
by two-plate shear test and Young’s modulus in the three main directions as well
as shear modulus in the three planes by ultrasonic testing were determined at
densified and undensified specimens. The bending properties were increased to
considerably higher levels and a compression ratio of 60% showed higher MOE and
MOR values than that of 40%; whereas for boards of the inner part of the trunk,
a compression ratio of 60% showed better results than that of 75%. The shear properties
were only slightly increased through densification. Densification can improve
the properties of oil palm wood. However, the wide range of density and properties
found in natural oil palm wood is also present in densified oil palm wood.
author:
- first_name: Nathan
full_name: Kölli, Nathan
id: '73742'
last_name: Kölli
- first_name: Katja
full_name: Frühwald-König, Katja
id: '26232'
last_name: Frühwald-König
citation:
ama: Kölli N, Frühwald-König K. Elasto-mechanical properties of thermo-hygro-mechanical
(THM) densified oil palm sawn timber. Wood material science and engineering
. Published online 2024:1-18. doi:10.1080/17480272.2024.2317977
apa: Kölli, N., & Frühwald-König, K. (2024). Elasto-mechanical properties of
thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood Material
Science and Engineering , 1–18. https://doi.org/10.1080/17480272.2024.2317977
bjps: Kölli N and Frühwald-König K (2024) Elasto-Mechanical Properties of
Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber. Wood material
science and engineering 1–18.
chicago: Kölli, Nathan, and Katja Frühwald-König. “Elasto-Mechanical Properties
of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” Wood Material
Science and Engineering , 2024, 1–18. https://doi.org/10.1080/17480272.2024.2317977.
chicago-de: 'Kölli, Nathan und Katja Frühwald-König. 2024. Elasto-mechanical properties
of thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood material
science and engineering : 1–18. doi:10.1080/17480272.2024.2317977,
.'
din1505-2-1: 'Kölli, Nathan ; Frühwald-König, Katja: Elasto-mechanical
properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. In:
Wood material science and engineering . London, Taylor & Francis (2024),
S. 1–18'
havard: N. Kölli, K. Frühwald-König, Elasto-mechanical properties of thermo-hygro-mechanical
(THM) densified oil palm sawn timber, Wood Material Science and Engineering .
(2024) 1–18.
ieee: 'N. Kölli and K. Frühwald-König, “Elasto-mechanical properties of thermo-hygro-mechanical
(THM) densified oil palm sawn timber,” Wood material science and engineering
, pp. 1–18, 2024, doi: 10.1080/17480272.2024.2317977.'
mla: Kölli, Nathan, and Katja Frühwald-König. “Elasto-Mechanical Properties of Thermo-Hygro-Mechanical
(THM) Densified Oil Palm Sawn Timber.” Wood Material Science and Engineering
, 2024, pp. 1–18, https://doi.org/10.1080/17480272.2024.2317977.
short: N. Kölli, K. Frühwald-König, Wood Material Science and Engineering (2024)
1–18.
ufg: 'Kölli, Nathan/Frühwald-König, Katja: Elasto-mechanical properties of
thermo-hygro-mechanical (THM) densified oil palm sawn timber, in: Wood material
science and engineering (2024), S. 1–18.'
van: Kölli N, Frühwald-König K. Elasto-mechanical properties of thermo-hygro-mechanical
(THM) densified oil palm sawn timber. Wood material science and engineering .
2024;1–18.
date_created: 2024-02-25T07:32:31Z
date_updated: 2025-06-25T12:42:37Z
department:
- _id: DEP7018
- _id: DEP1309
doi: 10.1080/17480272.2024.2317977
external_id:
isi:
- '001170089500001'
isi: '1'
keyword:
- Bending strength
- densification
- e-modulus
- g-modulus
- shear strength
language:
- iso: eng
page: 1-18
place: London
publication: 'Wood material science and engineering '
publication_identifier:
eissn:
- 1748-0280
issn:
- 1748-0272
publication_status: published
publisher: Taylor & Francis
quality_controlled: '1'
status: public
title: Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil
palm sawn timber
type: scientific_journal_article
user_id: '83781'
year: '2024'
...
---
_id: '6945'
abstract:
- lang: eng
text: 'Sustainable use of renewable raw materials is an important issue of policy
and industry. Wood prices are rising because of increasing market demand while
simultaneously forests are challenged through conservation issues, deforestation
and hazards. The main reasons for deforestation are agriculture, infrastructure
and wood harvesting. Oil palm plantations stock on former tropical forest land
and cover some 25 Mio ha worldwide. They are replanted every 25 years due to reduced
productivity. Using the available wooden trunk material of the cleared plantation
not only makes sense in ecological terms but is also a big chance for economy
and trade. Research over the last 30 years has led to several ideas in the use
for products. The biggest challenge is the anatomical structure of palm wood which
is different to coniferous or broadleaf trees. Hard vascular bundles are embedded
in low-density parenchyma storage tissue with high moisture content. The soft
and sponge-like parenchyma tissue can be compressed easily and a significant share
of the water (mc up to 600 % based on dry wood) can be squeezed out. Through press
drying, the volume of the parenchyma can be reduced and the wood density increases.
Wood strength and stiffness are related to its density and can be improved by
densification. TH OWL developed a four-step densification process for oil palm
boards. Oil palm lumber was produced from oil palm trunks in a sawmill and then
densified under defined conditions. The densification process includes (1) compression
to remove a certain percentage of the palm sap, (2) plastification under heat
and moisture to soften the wood, (3) hot compression to achieve the densification
and remove more water, and (4) press-drying to dry and harden the material. A
future perspective on how the laboratory tests could be scaled up to an industrial
application with a possible machinery set-up is presented. '
author:
- first_name: Nathan
full_name: Kölli, Nathan
id: '74242'
last_name: Kölli
citation:
ama: 'Kölli N. Densification and Press-Drying of Wet Oil Palm Lumber. In: Young TM,
Petutschnigg A, eds. 6th International Conference on Process Technologies
for the Forest and Biobased Products Industries PTF BPI 2021 . ; 2021.'
apa: Kölli, N. (2021). Densification and Press-Drying of Wet Oil Palm Lumber. In
T. M. Young & A. Petutschnigg (Eds.), 6th International Conference on
Process Technologies for the Forest and Biobased Products Industries PTF BPI
2021 .
bjps: Kölli N (2021) Densification and Press-Drying of Wet Oil Palm Lumber.
In Young TM and Petutschnigg A (eds), 6th International Conference on Process
Technologies for the Forest and Biobased Products Industries PTF BPI 2021 .
chicago: Kölli, Nathan. “Densification and Press-Drying of Wet Oil Palm Lumber.”
In 6th International Conference on Process Technologies for the Forest and
Biobased Products Industries PTF BPI 2021 , edited by Timothy M. Young and
Alexander Petutschnigg, 2021.
chicago-de: 'Kölli, Nathan. 2021. Densification and Press-Drying of Wet Oil Palm
Lumber. In: 6th International Conference on Process Technologies for the Forest
and Biobased Products Industries PTF BPI 2021 , hg. von Timothy M. Young und
Alexander Petutschnigg.'
din1505-2-1: 'Kölli, Nathan: Densification
and Press-Drying of Wet Oil Palm Lumber. In: Young
, T. M. ; Petutschnigg, A.
(Hrsg.): 6th International Conference on Process Technologies for the Forest
and Biobased Products Industries PTF BPI 2021 , 2021'
havard: 'N. Kölli, Densification and Press-Drying of Wet Oil Palm Lumber, in: T.M.
Young , A. Petutschnigg (Eds.), 6th International Conference on Process Technologies
for the Forest and Biobased Products Industries PTF BPI 2021 , 2021.'
ieee: N. Kölli, “Densification and Press-Drying of Wet Oil Palm Lumber,” in 6th
International Conference on Process Technologies for the Forest and Biobased
Products Industries PTF BPI 2021 , St. Simons Island, Georgia / USA, 2021.
mla: Kölli, Nathan. “Densification and Press-Drying of Wet Oil Palm Lumber.” 6th
International Conference on Process Technologies for the Forest and Biobased
Products Industries PTF BPI 2021 , edited by Timothy M. Young and Alexander Petutschnigg,
2021.
short: 'N. Kölli, in: T.M. Young , A. Petutschnigg (Eds.), 6th International Conference
on Process Technologies for the Forest and Biobased Products Industries PTF
BPI 2021 , 2021.'
ufg: 'Kölli, Nathan: Densification and Press-Drying of Wet Oil Palm Lumber,
in: Young , Timothy M./Petutschnigg, Alexander (Hgg.): 6th International
Conference on Process Technologies for the Forest and Biobased Products Industries
PTF BPI 2021 , o. O. 2021.'
van: 'Kölli N. Densification and Press-Drying of Wet Oil Palm Lumber. In: Young TM,
Petutschnigg A, editors. 6th International Conference on Process Technologies
for the Forest and Biobased Products Industries PTF BPI 2021 . 2021.'
conference:
end_date: 2021-11-03
location: St. Simons Island, Georgia / USA
name: PTF BPI 2021 (Process Technologies for the Forest & Biobased Product Industries)
start_date: 2021-11-01
date_created: 2022-01-06T11:43:06Z
date_updated: 2023-10-30T15:20:10Z
department:
- _id: DEP7018
- _id: DEP1309
editor:
- first_name: 'Timothy M. '
full_name: 'Young , Timothy M. '
last_name: 'Young '
- first_name: 'Alexander '
full_name: 'Petutschnigg, Alexander '
last_name: Petutschnigg
keyword:
- Oil Palm Wood
- Densification
- Drying
language:
- iso: eng
publication: '6th International Conference on Process Technologies for the Forest and
Biobased Products Industries PTF BPI 2021 '
publication_status: published
status: public
title: Densification and Press-Drying of Wet Oil Palm Lumber
type: conference
user_id: '83781'
year: '2021'
...