Drvna industrija, Vol. 71 No. 1, 2020.
Izvorni znanstveni članak
https://doi.org/10.5552/drvind.2020.1901
Effect of Water Repellents on Hygroscopicity and Dimensional Stability of Densified Fir and Aspen Woods
Huseyin Pelit
orcid.org/0000-0002-5706-473X
; Faculty of Technology, Duzce University, Department of Wood Products Industrial Engineering, Duzce, Turkey
Fatih Emiroglu
; Faculty of Technology, Duzce University, Department of Wood Products Industrial Engineering, Duzce, Turkey
Sažetak
This study investigated the effect of pre-impregnation with water-repellent agents on the hygroscopicity and dimensional stability of fir (Abies bornmulleriana Mattf.) and aspen (Populus tremula L.) woods. After pre-vacuum treatment, the samples were impregnated at atmospheric pressure with paraffin, linseed oil and styrene, and then densified at compression rates of 20 % and 40 % at 120, 150 and 180 °C. The results showed that water repellents significantly affected the hygroscopicity and dimensional stability of the densified wood samples. Compression recovery rate (CRR), thickness swelling (TS), equilibrium moisture content (EMC), and water absorption (WA) values of the densified samples decreased with impregnation pretreatments. The linseed oil treatment gave more positive CRR and TS results than paraffin. Lower EMC and WA values were found in the paraffin-treated samples. However, the most successful results for all tested properties were determined in the styrene pretreated samples in which hygroscopicity decreased and dimensional stability increased (especially for aspen) due to increases in the compression rate and temperature related to densification conditions. In the styrene pretreated samples, the high temperature (180 °C) and compression rate (40 %) significantly reduced CRR, TS, EMC and WA, total dimensional stability was nearly achieved and the water repellent effectiveness was close to 100 %.
Ključne riječi
densification; dimensional stability; hygroscopicity; impregnation; water repellents
Hrčak ID:
235807
URI
Datum izdavanja:
17.3.2020.
Posjeta: 1.374 *