Combination of polyethylene glycol impregnation and paraffin heat treatment to protect round bamboo from cracking

Abstract

Round bamboo has drawn more and more attention in architecture, decoration and recreational products. Splitting brings some safety problems, which shorten the service life of round bamboo. In this paper, three schemes were adopted as follows to solve the problem: round bamboo was impregnated in polyethylene glycol (PEG)-1000 solution alone, heat treatment in paraffin alone or treated with the combination of PEG impregnation and paraffin heat treatment (PEG–PH). The treated bamboo was exposed outdoors for 26 weeks to evaluate the development of cracks. Results showed as follows: the initial split of PEG–PH-treated bamboo appeared after 22 weeks, while that of the controls after 2 weeks, the total length of cracks was 2271.31 and 873.5 mm for the control and PEG–PH-treated bamboo, respectively. To reveal the reasons for reduced cracks, scanning electron micrograph (SEM) was employed to observe the microstructure of bamboo; besides, hydrophobicity of bamboo was characterized by the water contact angle. PEG can swell the cell wall and the better hydrophobicity of round bamboo could be achieved after PEG–PH treatment. Therefore, the combination of PEG immersion and paraffin heating is an effective and practicable method in bamboo treatment, especially for round bamboo with high moisture content.

Enhanced properties of single-layer particleboard made from oil palm empty fruit bunch fibre with additional water-soluble additives

“…The high IB strength of PG4 could be achieved with the presence of polyurethane in PEG. PEG is normally used to stabilise green wood to prevent it from cracking, splitting and shrinking (Rao et al 2019). Due to the high polarity and the hydrogen bonding between polyurethane and the substrates, polyurethane was also used to bind various substrates such as metal, plastic, rubber, and wood.…”

Enhanced durability of round bamboo treated with copper naphthenate under heat-cold impregnation

“…Unfortunately, the first two methods only provide limited durability and are usually not durable for outdoor application. Smoking can be applied to protect round bamboo from fungi and insects, but it is a time-consuming procedure which generally takes several months and the colour of bamboo changes to bronze or dark yellow, which is not accepted in some applications [ 3 ]. The traditionally high-temperature treatment for bamboo strips and slices in a saturated steam atmosphere is unsuitable for round bamboo due to the problem of cracking [ 4 ].…”

“…Impregnation of round bamboo with preservative solutions such as alkaline copper quaternary (ACQ), copper azole (CuAz) and organic biocides formulations are commonly used at present, but have low chemical penetration and distribution abilities [ 5 ]. The combination of polyethylene glycol (PEG)/boron and wax heat treatment has been used to improve the cracking and decay resistance of round bamboo [ 2 , 3 ], while the leaching of both PEG and boron are still not solved. To meet the requirement for diverse applications, it is necessary to find a feasible way to introduce the fungicide into the inner part of round bamboo and simultaneously enhance its leaching resistance.…”

Failure Mechanisms of Structural Bamboo Using Microstructural Analyses

“…However, the bamboo species has several technical challenges such as geometric and mechanical inconsistency along the longitudinal section [22,23]. e bamboo was facing natural resistance deterioration in less than 24 months [24], and it was normally decaying in about 4 years if applied outdoor without any treatment [25,26]. Furthermore, the bamboo species tend to show sideways grain splitting owing to lopsided shrinkage throughout natural seasoning [27].…”