Effects of different energy intensities of microwave treatment on heartwood and sapwood microstructures in Norway spruce

Ganguly, Sauradipta (author), Balzano, Angela (author), Petrič, Marko (author), Kržišnik, Davor (author), Tripathi, Sadhna (author), Žigon, Jure (author), Merela, Maks (author)

Microwave modification can increase the permeability of wood by delaminating and rupturing its anatomical microstructures at their weak points. A high degree of intensity of microwave modification can cause significant structural damage to the microstructures of wood, resulting in poorer strength properties. The objective of this study was to evaluate the changes in the anatomical structure of Norway spruce (Picea abies (L.) Karst.) heartwood and sapwood after microwave modification in order to develop the most effective treatment in terms of applied energy without causing significant structural damage. Analysis with light and scanning electron microscopy were performed to evaluate the effect of microwave treatment for two different energy intensities, moderate and high intensity. The results indicated structural changes in the tracheid cells. Microscopy showed varying degrees of modification within the wood microstructure, with the heartwood samples showing a greater anatomical distortion compared to their sapwood counterparts. Furthermore, the samples were subjected to pycnometric density measurements, which indicated a reduction in skeletal and absolute density after microwave modification, for both high and moderate intensity treatment on sapwood and heartwood samples. With increasing microwave energy, a gradual increase in specific pore volume and porosity percentage of the samples were also detected.

• Language: English
• Keywords: Picea abies, microwave treatment, light microscopy, scanning electron microscopy, wood anatomy, wood properties, density, permeability, porosity
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 16 str.
• Numbering: Vol. 12, iss. 5, art. 598
• PID: 20.500.12556/RUL-127564
• UDC: 630*8
• ISSN on article: 1999-4907
• DOI: 10.3390/f12050598
• COBISS.SI-ID: 62577411
• Publication date in RUL: 15.06.2021

Record is a part of a journal

• Title: Forests
• Shortened title: Forests
• Publisher: MDPI
• ISSN: 1999-4907
• COBISS.SI-ID: 3872166

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 10.05.2021

Secondary language

• Language: Slovenian
• Keywords: obdelava z mikrovalovi, svetlobna mikroskopija, elektronska vrstična mikroskopija, anatomija lesa, lastnosti lesa, gostota, permeabilnost