Annals of Warsaw University of Life Sciences SGGW (Forestry and Wood Technology)

Comparison of the chemical composition of domestic common hornbeam (Carpinus betulus L.) wood and exotic yakal (Shorea astylosa Foxw.) wood

Dominik Sierant — 2021-08-18

Comparison of the chemical composition of domestic common hornbeam (Carpinus betulus L.) wood and exotic yakal (Shorea astylosa Foxw.) wood. The study was carried out to compare the chemical composition of domestic hornbeam wood with exotic yakal wood, which is an endemic species occurring in the Philippines. Species of similar structural structure occurring in different areas were studied. Extractives, cellulose (including α-cellulose), holocellulose (including hemicelluloses), lignin and ash contents were analyzed. The obtained results indicated lower content of cellulose, α-cellulose, lignin, extractives and ash in hornbeam wood as compared to yakal wood. On the other hand, a much higher amount of hemicelluloses (by 12 percentage points) was found in hornbeam wood. Probably, the main reason for the differences in the chemical composition of wood were different habitat and climatic conditions, in which the studied species were growing.

The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen

Tomasz Gliszczyński — 2021-08-18

The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen. The aim of this work was studying black poplar wood (Populus nigra L.) selected properties modified with furfuryl alcohol and styrene. Maleic anhydride and glicydyl methacrylate were used as cross-linking agents. For modified wood samples the index of WPG, density, hardness, water absorbability, colour change and volume swelling were tested. Each test results were compared with values for unmodified black poplar wood. During furfurylation process density of poplar wood samples increased up to 1.3 times. Addition of maleic anhydride to furfurylation process caused increase of WPG index about 5-6 % and at the same time slightly decrease of wood Brinell hardness. Water absorbability and volume swelling of furfurylated poplar wood after 10080 min (168 h) of soaking in water were reduced more than 50% relative to unmodified wood. Polymerization in lumen with using styrene caused increase of density up to 2 times, increase of Brinell hardness up to 1.5 times, while WPG index was in the range from 50.8 to 116.6%. For polymerization in lumen process, water absorbability and volume swelling after 10080 min (168 h) of soaking in water were reduced more than half as well. Furfurylation caused intensive wood darkening when polymerization in lumen changed wood colour slightly. Addition of maleic anhydride to furfuryl alcohol caused an even greater darkening of the wood. The studies proved, that chemical modification

significantly improved selected properties of poplar wood.

Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards

Karol Zaraziński — 2021-08-18

Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards. As a part of the study, one-layer particle-fibre boards with 12 mm thick and of average density 650 kg/m3 were manufactured from plantation poplar ‘Hybrid 275’ wood.. For the control variant a typical industrial raw material (pine wood) was used. The following properties were determined for the boards: modulus of rapture (MOR), density profile, modulus of elasticity at static bending (MOE), internal bond (IB), thickness swelling (TS) after 2h and 24h soaking in water. On the basis of conducted study, it was found that the addition of poplar fibers to particle-fibre boards in most cases has a positive effect on the values of determined properties – an increase in strength was noted, except for internal bond (IB). In the case of thickness swelling of the boards after 24 h soaking in water, it was noted that with the increase in the share of poplar fibers in the boards, the value of the tested property decreased (which was not clear in the case of thickness swelling of boards after 2 h soaking in water).

A study of natural durability of selected coniferous wood species from north Asia affected by the fungus Coniophora puteana (Schumach.) P. Karst.

Boguslaw Andres — 2021-08-18

The aim of prestened study was to determine the natural durability of selected coniferous wood species from Asia to the effect of Coniophora puteana (Schumach.) P. Karst., which causes brown rot. The species tested were: Larix gmellini (Rupr.) Kuzen., Larix sibirica Ledeb. and Pinus sibirica Du Tour.. The test was conducted on the basis of PN-EN 350:2016-10 and PN-EN 113:2000. As a result of the research durability classes were determined. Wood durability of tested Asian species was compared with the domestic wood species such as Pinus sylvestris L. and Larix decidua Mill.. The most durable of the tested wood species was Larix sibirica Ledeb., while the European larch showed comparable durability. The wood of Larix gmellini (Rupr.) Kuzen. showed the lowest persistence among the tested species.

An impact of surface spray and pressing temperature on the properties of high density fibreboards

Conrad M. Sala — 2021-08-18

An impact of surface spray and pressing temperature on the properties of high density fibreboards. The objective of this study was to investigate the effects of chosen process parameters: water spray amount and 3rd press heating section temperature on the mechanical, physical properties of ultrathin (2.5 mm) industrial high-density fibreboards (HDF) produced with 5% of recovered HDF (rHDF) addition. Boards were produced with 0 ml/m2 – V0, 8 ml/m2 – V8, 16 ml/m2 – V16 and 32 ml/m2 – V32 of surface water spray addition on top and bottom side in industrial hot continuous press with 3rd heating section temperature setups: 145oC (V45), 160oC (V60) and 175oC (V75). After variants examination with different surface water spray amount it was found, that there is roughly linear positive correlation for MOR increase for up to 10% comparing V0 to V32 and for surface roughness decrease for up to 31%. Surface water spray improved IB for up to 21% while WA decreased for up to 9% for V8 comparing to HDF produced without surface water spray addition. According to 3rd press heating section temperature influence – MOR and MOE has increased while other mechanical properties worsen with pressing temperature increase – drop in IB and SS.

Influence of the microstructure of tool coatings based on Ti and Al on the blunting process during chipboard processing

Paweł Czarniak — 2021-08-18

Influence of the microstructure of tool coatings based on Ti and Al on the blunting process during chipboard processing.This work concerns three different tool coatings containing Ti and Al. i.e. TiN, AlTiN, TiAlSiN applied to cutting tools used in the machining of wood materials. In the case of the AlTiN coating, a multilayer structure with alternately arranged AlTiN and TiN nano-layers was used. The above coatings were applied to standard replaceable knives used for CNC milling heads made of WC-Co cemented carbide. The deposition process was carried out using the RF Magnetron Sputtering method. During the measurement on a workshop microscope, the VBmax index measured on the clearance face was adopted as the wear criterion. The research proved a very good behaviour of the TiN/^AlTiN multilayer coating, for which the longest average service life which was recorded exceeded the results obtained for the reference tool by about 30%. The addition of silicon, which was supposed to increase the abrasion resistance, only did not improve the durability of the blade, it actually worsened it by 6%. In addition, the coating, which has been widely used in the machine industry for a very long time, i.e. TiN, did not extend the tool life significantly (+ 7%).

Selected physical and mechanical properties of particleboards produced from lignocellulosic particles of black chokeberry (Aronia melanocarpa (Michx.) Elliott)

Grzegorz Kowaluk — 2021-08-18

Selected physical and mechanical properties of particleboards produced from lignocellulosic particles of black chokeberry (Aronia melanocarpa (Michx.) Elliott). The aim of the research was to confirm the possibility of using woody particles of black chokeberry (Aronia melanocarpa (Michx.) Elliott) stems as an alternative raw material in particleboard technology. As part of the work, particle boards from woody chokeberry particles were produced in laboratory conditions and selected physical and mechanical properties of the obtained boards were tested. The research confirmed that it is possible to manufacture boards for the furniture industry using lignocellulosic particles of black chokeberry (Aronia melanocarpa (Michx.) Elliott) meeting the requirements for P2 boards according to PN-EN 312.

Changes in poplar (Populus trichocarpa) wood porous structure after liquid hot water (LHW) pretreatment

Florentyna Akus-Szylberg — 2021-08-18

Changes in poplar (Populus trichocarpa) wood porous structure after liquid hot water (LHW) pretreatment. The aim of this research was to investigate the effect of applying different hydrothermal pretreatment conditions on the porous structure of poplar wood. Porosity is recognised as an important factor considering efficiency of an enzymatic hydrolysis as a step of bioethanol production. Native poplar wood as well as solid fractions after pretreatment performed at different temperatures (160 °C, 175 °C and 190 °C) were analysed. Porous structure was examined with an inverse size-exclusion chromatography (ISEC) method. Results indicated a significant development of the porous structure of the biomass with increasing porosity along with the growing temperature of the LHW process. The temperature of 190 °C was chosen as the most promising condition of poplar wood LHW pretreatment in terms of the efficiency of the subsequent steps of bioethanol production. The obtained results were consistent with the previous experimental data procured during analysis of the LHW pretreated poplar wood and its subsequent enzymatic hydrolysis yield.

Change in hydrolytic enzyme efficiency over time

Dominika Szadkowska — 2021-08-18