Shear strength in friction welded joint of poplar wood impregnated with copper-based wood preservative

Mustafa Zor,Ahmet Can

doi:10.4067/s0718-221x2021000100409

Abstract

Environmentally friendly processes are of great interest and considerably needed due to the worldwide problem of pollution. Linear vibration welding of timber structural elements provides new opportunities to potentially achieve structural joints. Mechanically induced vibrational wood fusion welding is shown to be due mostly to the melting and flowing of some amorphous, cells-interconnecting polymer material in the structure of wood, mainly lignin, but also hemicelluloses. In this study, poplar (Populus euramericana) samples were impregnated with alkaline copper quat (ACQ) in order to enhance welding performance. Chemical changes of the impregnated and welded specimens were characterized by FT-IR techniques. A decrease in the proportion of unoxidized phenolic groups in the lignin were observed by FT-IR and the decreased joint strength observed is impregnated wood. After impregnation, shear strength decreased by 37 % to 54 %. The X-ray CT-scanning results revealed that the average density of the poplar wood (368 kg/m3) increased to 710 kg/m3 by welding

Highlights

Water-based impregnating agents have been used in the wood protection industry for many years
Shear strength tests were carried out to understand the effects of different concentrations of alkali copper quat (ACQ) on welded bonds as seen in Table 2, in welded poplar wood impregnated at different concentrations, the shear resistance values of welded wood decreased as the concentration increased
As for welded poplar wood after impregnation, the highest shear strength was found in the control sample (7,59MPa), whereas the lowest was found in 5% ACQ impregnated (3,42 MPa)

Summary

Introduction

Water-based impregnating agents have been used in the wood protection industry for many years. The compatibility of impregnating agents with glues is another important factor affecting adhesion. The type of impregnation agent, the method of application, the amount of retention and surface interaction all affect the adhesion resistance (Vick and Christiansen 1993). The interaction of the glues used in the joining of the wood with the impregnating agents affects the end-use performance. For this purpose, several researchers have stated that the impregnation process decreases the adhesion resistance (Örs et al 2004, Özçifçi 2006, Gardner et al 2015, Kesik et al 2016)

Methods

Results

Conclusion