Ayhan Özçifçi

Bonding strength of poly(vinyl acetate)-based adhesives in some wood materials treated with impregnation

This experimental study was carried out to determine the bonding strength of poly(vinyl acetate)-based (PVAc) adhesives [i.e., Klebit 303 (K303), Kleiberit 305.0 (K305.0), and Super Lackleim 308 (SL308)] for some impregnated wood materials used in woodworking industries. For this purpose, Oriental beech (Fagus orientalis lipsky), Uludaǧ fir (Abies bormulleriana mattf.), and Scotch pine (Pinus sylvestris lipsky) woods were impregnated with tanalith-CBC (T-CBC) and imersol-WR 2000 (I-WR 2000) by dipping and vacuum method according to the procedure of ASTM-D 1413-76 standards. The shear strength test was conducted on the connection surface of samples jointed by four different adhesives. The test results showed that the highest shear strength (11.84 N/mm2) was obtained for the wood materials of Oriental beech treated by T-CBC with K303 by using the dipping method. The lowest shear strength (3.1 N/mm2) was obtained for Scotch pine treated by T-CBC with K305.0 by using the vacuum method.

Effects of boron compounds on the bonding strength of phenol-formaldehyde and melamine-formaldehyde adhesives to impregnated wood materials

Wood materials are increasingly being used in the construction of structural beams, sports equipment, etc. This study was carried out to determine the bonding strength of phenol-formaldehyde (PF) and melamine-formaldehyde (MF) adhesives to impregnated wood materials. For this purpose, brutia pine (Pinus brutia Ten) and elm (Ulmus compestris L.) woods were impregnated with borax (Bx), boric acid (Ba), Bx + Ba (wt:wt 50:50%), di-ammonium phosphate (D), [D + (Bx + Ba)]/(50 + (25 + 25%), w/w) and Tanalith-C 3310 (T-C 3310) using the vacuum method according to ASTM-D 1413-76. The effects of wood species, impregnating material and type of adhesive on the bonding strength were determined. The highest shear strength (11.09 N/mm2) was obtained from elm wood control (i.e., without any impregnating materials) samples with MF; thus, the impregnation process negatively affected the adhesive bonding strength. Impregnating materials, especially those containing oily or similar solutions such as T-C 3310, are not advised for wood elements which are subjected to shear.

Construction wood industry and the sector's impact on economical growth in Turkey

Wood is an important building material, which is lightweight and easy to process and repair, and it is widely available for the construction industry. The research task in the present study is to investigate the relationship between the manufacture data for construction wood and the gross domestic product (GDP). In order to determine the aforementioned relation between the manufacture data for construction wood and the GDP, the Engle-Granger co-integration, error correction model (ECM) and the Granger causality tests were applied. A direct proportionality was determined in the relationship between the manufacture of construction wood and the GDP as a result of this study.

Effects of Outdoor Exposures and Boron Compounds on Bonding Strength of Desmodur-VTKA Adhesive

This study was carried out to determine the shear strength of an adhesive on weathered wood, impregnated with a boron compound, using a long term dipping method. The shear strength of D-VTKA adhesive on two types of wood species each containing one of two types of the impregnated material, under different weathering conditions, was measured. The results showed that the highest shear strength (11.01 N/mm2) was obtained with the control samples of untreated, oriental beech wood, and the lowest was obtained for Scots pine impregnated with boric acid after two seasons of exposure (six months). Weather conditions affected the shear strength in a negative way. Finally the results showed that if the boron compounds were supported with non-leaching chemicals, they could be recommended as fire-retardant additives and would extend the life of wood bonded with D-VTKA adhesive.