WOOD RESEARCH Volume 62, Number 6, 2017
Turkay Turkoglu, Yahya Kabasakal, Ergun Baysal, Ahmet Gunduz, Mustafa Kucuktuvek, Dursun Kemal Bayraktar, Hilmi Toker, and Huseyin Peker

Surface characteristics of heated and varnished Oriental beech after accelerated weathering

This study was performed to investigate some surface characteristics such as surface hardness, surface roughness, and color changes of heated and varnished Oriental beech (Fagus orientalis Lipsky) after accelerated weathering. Heat treatment of Oriental beech wood was carried out by hot air in an oven for 0.5, 1, and 1.5 h at 210, 220, and 230°C. After heat treatment, Oriental beech wood specimens were varnished using a polyurethane varnish. The results showed that accelerated weathering generally caused increase of surface hardness of Oriental beech. Surface roughness and total color changes of heated and varnished Oriental beech were lower than only varnished (control) Oriental beech after accelerated weathering. Heated and varnished Oriental beech wood gave better surface characteristics than only varnished oriental beech after accelerated weathering.

WOOD RESEARCH Volume 62, Number 4, 2017
Agnieszka Jankowska, Magdalena Reder, and Tomasz Gołofit

Comparative study of wood color stability using accelerated weathering process and infrared spectroscopy

The objective of this study was to investigate effects of artificial weathering on color stability of six tropical wood species: Apuleia leiocarpa (Vog.) Macbride, Bagassa guianensis Aubl., Dipteryx odorata (Aubl.) Wild., Hymenea courbaril/Linn., Manilkara bidentata A. Chev., Tabebuia sp. Chemical composition of weathered wood was also studied by FT-IR spectra. With the progressive artificial weathering color of wood changed gradually. Hymenea courbaril Linn. wood occurred the greatest range of the total color change. The largest changes in intensity of the wood color took place at the beginning of artificial weathering process. FT-IR analysis indicated the occurrence of lignin and hemicellulose oxidative changes resulting in formation of carbonyl and carboxyl compounds during weathering. Oxidation products are the main cause of wood surface discoloration. Additionally, changes suggesting depolymerisation of cellulose were identified as well.

WOOD RESEARCH Volume 64, Number 6, 2019
Ahmet Gunduz, Ergun Baysal, Turkay Turkoglu, Mustafa Kucuktuvek, Caglar Altay, Huseyin Peker, and Hilmi Toker

Accelerated weathering performance of Scots pine preimpregnated with copper based chemicals before varnish coating. Part II: Coated with water based varnish

This study was designed to investigate some surface characteristics such as gloss, color, and surface hardness changes of Scots pine wood preimpregnated with some copper-based chemicals before varnish coating after accelerated weathering. While Adolit KD-5 (AD-KD 5), Wolmanit CX-8 (WCX-8), and Celcure AC-500 (CAC-500) were used as copper-based impregnation chemicals, water-based varnish (WBV) was used as a coating material. Results showed that surface hardness and gloss values of Scots pine were increased after accelerated weathering. Impregnated and WBV coated Scots pine gave better surface characteristics compared to only WBV coated Scots pine. In impregnation chemicals, while AD-KD 5 showed the most appropriate chemical, in terms of surface hardness and total color changes, CAC-500 was found the most valuable chemical in terms of gloss changes after 1000 h accelerated weathering exposure.