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The Effect of Treatment with Fire Retardant on Properties of Birch Veneer and Manufactured Fire-Resistant Plywood

Kawalerczyk Jakub, Dziurka Dorota, Pinkowski Grzegorz, Stachowiak-Wencek Agata, Walkiewicz Joanna, Mirski Radosław

Drewno : prace naukowe, doniesienia, komunikaty

2023

Vol. 66, nr 212

Art. no. 176617

The production of plywood from impregnated veneers allows a wood-based product protected in the entire cross-section to be obtained. The conducted research was focused on the properties of veneers impregnated with a mixture of potassium carbonate and urea, such as pH, wettability, colour change and surface roughness. In addition, the properties of plywood produced with melamineureaformaldehyde resin, such as the shear strength and formaldehyde emission, were the subject of research as well. It was found that the impregnated veneers were characterized by an increased pH, increased wettability, a completely different colour and unchanged surface roughness. Moreover, the impregnation of the veneers caused a decrease in the bonding quality of the plywood and a reduction in formaldehyde emissions from the finished product. It can be concluded that the melamineurea-formaldehyde adhesive is more suitable for the production of fire-resistant plywood than the urea-formaldehyde adhesive.

Effect of the Addition of Extractives on The Reduction Of Vocs Emissions from Lacquers in the liquid state

Brózdowski Jakub, Gajewski Erik, Szczepaniak Oskar M., Stachowiak-Wencek Agata

Drewno : prace naukowe, doniesienia, komunikaty

2023

Vol. 66, nr 211

Art. no. 1644-3985.437.04

The aim of this study was to determine the effect of the addition of extractive substances on the VOC emission of lacquer products in the liquid state. Three water-soluble acrylic resin products were investigated using the stationary phase microextraction technique in combination with gas chromatography coupled with mass spectrometry (SPME-GC/MS). The extraction of volatile compounds was analysed at three temperatures: 22 ℃, 35 ℃ and 45 ℃. 20 μg of an extract obtained from the leaves, branches and bark of black cherry (Prunus serotina Erhr.) were added to commercial products. Flavonoids accounted for almost 75% of the total phenols in the used extract. The spectrum of volatile compounds emitted by the liquid coating products selected for the studies was examined before and after adding the extract to them. It was found that the addition of black cherry extract caused a significant reduction in the emissions of volatile compounds emitted by the researched products. The compounds, whose amounts did not decrease under the influence of the addition of the extract, were esters of propenoic acid. The applied extract was a source of emissions from an additional compound: benzaldehyde. The total VOC emissions of the investigated liquid coating products was reduced by 8-55% and depended on the extraction temperature. The paper also proposes the mechanism of chemical reactions between phenolics and VOC, which may cause the reduction in VOC emissions from lacquer products. The IBM RXN tool was utilised to find possible reactions.

Utilization of post-fermentation maize waste by thermal conversion

Stachowiak-Wencek Agata, Zborowska Magdalena, Walkowiak Małgorzata, Waliszewska Hanna, Waliszewska Bogusława

Drewno : prace naukowe, doniesienia, komunikaty

2019

vol. 62, nr 204

115--126

One of the essential requirements in the running of a biogas plant is the proper management of the by-product resulting from the production of biogas, i.e. the post-fermentation mass. One of the possibilities for the treatment of a fixed post-fermentation fraction is its combustion. In this study, the basic physicochemical properties of the post-fermented pulp obtained from maize waste are determined in terms of their combustion potential. Parameters such as elemental analysis, moisture content, volatile matter content, ash content, heat of combustion and calorific value were determined for the raw material without pre- -treatment, as well as for the raw material after chemical hydrolysis and extrusion. The tested material was subjected to both acidic and alkaline hydrolysis. Acidic hydrolysis was carried out with sulfuric acid (concentration 3% and 7%) and alkaline hydrolysis with sodium hydroxide (concentration 1% and 3%). Under pre-treatment, the raw material was also subjected to low- and hightemperature extrusion. Low-temperature extrusion was carried out at 110°C, and high-temperature extrusion in the range 140–160°C. The purpose of the pre- -treatment was to achieve the fragmentation of lignin, a substance not degraded by enzymatic hydrolysis. On the basis of the research, the suitability of the analyzed raw material for thermal utilization was determined. After drying, the residue after fermentation had high calorific value, similar to that of other types of biomass. It also had a lower content of volatile matter and increased ash content compared with the non-fermented raw material. High nitrogen content was a significant parameter distinguishing the studied material from other types of biomass. The decision to burn waste should be preceded by careful analysis of its physical and chemical properties, as this enables appropriate preventive action to be taken.