COMPREHENSIVE APPROACH TO ENSURE DURABILTY OF EXTERNAL WOODEN STRUCTURES

The article deals with durability of wood, durability of wooden structures and surface modification of wood. We are trying to eliminate the factors causing degradation of wood with the use of photocatalytic materials. Those materials are efficient UV absorbers and they are able to destroy biological aggressors also. The planar particles of titanium oxide TiO2 were chosen for the purpose of our research and applied on a wooden surface. In our case, we used a water solution of TiO2. The main goal of our work was to study the interaction between planar particles of TiO2 and wood matter. The samples of pine wood (Pinus sylvestris) were monitored for 255 days and subsequently evaluated using an electron microscope. The use of TiO2 was compared with reference material and a reference commercial coating.

Determination of antimicrobial and fungicidal properties of experimental disinfectant "Sukhodez"

The results of the study of antimicrobial and fungicidal properties of the experimental preparation “Sukhodez” against microorganisms E. coli, Salmonella enteritidis, Staphylococcus aureus and fungi Candida albicans in the laboratory are presented. The aim of the research. To study the antimicrobial and fungicidal properties of powdered disinfectant and analyze the prospects for its further use in a set of anti-epizootic measures in particular in poultry farms. Materials and methods. The research was conducted during 2021 at the Department of Veterinary Examination, Microbiology, Zoohygiene and Safety and Quality of Animal Products of the Faculty of Veterinary Medicine of Sumy National Agrarian University. Evaluation of bactericidal properties of the experimental agent “Sukhodez” was determined on museum strains of E. coli ATCC 25922, Salmonella enteritidis ATCC 13076 and Staphylococcus aureus ATCC 6538, fungicidal properties were studied on fungi Candida albicans. All cultures were standardized to 109 CFU / cm3. Results. It is established that as a result of the conducted researches at studying preparation “Sukhodez” antimicrobic properties, it had high efficiency concerning action on strains of both gram-positive and gram-negative bacteria. It had a detrimental effect on bacteria when applied to concrete at an exposure of 1 hour with a rate of 75 mg per 1 m2, and had the same effect as when applied to a wooden surface, where it expressed antimicrobial action at a rate of 50 mg/m2 after 4 hours. When determining the fungicidal properties, it was found that when exposed to 5 hours, the preparation “Sukhodez” had an effect on study contaminated objects with a rate of 50 mg/m2, and with a rate of 75 mg/m2 inhibited the growth of fungi for 1 hour. Conclusions. It was found that the most sensitive to the preparation “Sukhodez” were the culture of Salmonella enteritidis – at a rate of 25 g / m2 and action on concrete and wooden surfaces, the disinfectant inhibited the growth of the culture when exposed to 5 hours, and at a rate of 50 g / m2 – for 2 years. Staphylococcus aureus was the most stable bacterial culture, so at a rate of 50 g / m2 on concrete and wood surfaces, bacterial growth was inhibited for 4 and 5 hours, respectively. At the same time, in the study of fungicidal properties, “Sukhodez” showed a fungicidal effect on Candida albicans when applied to a concrete surface at a rate of 50 mg / m2 for 3 hours, when applied to a wooden surface – for 4 hours. In general, at a rate of 75 g / m2, “Sukhodez” has an instant bactericidal and fungicidal effect on bacteria and fungi applied to concrete and wooden surfaces

Protection of Wood to against Degradation by TiO2: Scanning Electron Microscopy and Energy Dispersive Spectroscopy

External wooden structures have own place in the building industry for ages. The problem is that wood easily degrades due to UV radiation, atmospheric conditions and biological aggressors. We are trying to eliminate degradable factors by photocatalytic materials (namely titanium oxide). Those materials are efficient UV absorbers and they are able to destroy biological aggressors also. Nowadays, there is no information about the interactions between wooden surface and non-photoactive or photoactive forms of TiO2. TiO2 exists in many morphological forms. The planar particles were chosen for the purpose of our research and applied on a wooden surface. The samples of wood (namely pine) were monitored for 255 days and subsequently evaluated using an electron microscope. The use of TiO2 was compared with reference material and a reference commercial coating.

The color change analysis of historic wooden remains after fire-suppression by fluorinated chemical gases

Many wooden Chinese historic buildings are destroyed due to the ravages of frequent fire disasters. The fire risk of historic buildings are highly enlarged since a long-time weathered wooden structures in the natural environment. The clean fire-extinguishing technology using fluorinated chemical gases to put out a historic building fire rapidly at the initial stage is highly recommended and widely used. However, the gaseous hydrogen fluoride (HF) yielded during the fire suppression process could be a potential method to result in secondary damage due to its corrosiveness. Nowadays, experiments were employed to clarify the effect of fire suppression on the surface of historic wooden buildings. Five traditional fluorinated chemical gases, H-37, FK-5-1-12, H-1323, H-2402, and H-1301, are used to suppress a fixed flame. The wooden samples, including a Dao Talisman board, a painting paper, and wooden chips, are placed in a chamber. Wooden chips consist of traditional and weathered samples (acting as the Chinese historic buildings). The concentration of gaseous products yielded from fire suppression are monitored by a gas-FTIR from ABB, and the surface analysis is conducted by a Quanta FEG SEM–EDX from FEI. It is observed that flame enhancement happens at the early stage of fire suppression and varies with fire agents. The amount of F-deposited on the wooden surface is positively correlated with a total amount of gaseous HF. The color change mechanism of the wooden surface is comprehensive, although the amount of HF is a leading factor. The influence of HF on color change depends on the amount of both gaseous H2O and HF. It is concluded that the value of L* of the traditional chip is much easier to be reduced comparing with weathered samples with the same wood grain. The reduction of $${\mathrm{b}}^{*}$$ b ∗ value of weathered samples is much larger than the traditional ones. It suggests the weathered chips show a color shift toward blue because of fire suppression. The present study hopes to provide a basic acknowledgment for the comprehensive understanding of secondary damage caused by fire suppression.

Effect of Microcapsules of a Waterborne Core Material on the Properties of a Waterborne Primer Coating on a Wooden Surface

Microcapsules of a waterborne core material were prepared using a waterborne primer. The microcapsules of the waterborne core material were added to the waterborne primer to explore the effects of different core–shell ratios and mass fractions of the microcapsules on the property of the waterborne primer coating on the wooden surface. The results show that as the mass fraction of the microcapsules increased, the chromatic aberration increased by degrees, the glossiness decreased gradually, and the hardness increased by degrees, whilst—except for the coating with 0.50:1 microcapsules—the adhesion decreased gradually. When the mass fraction of the microcapsules increased, the impact resistance increased first and decreased later, or remained unchanged after reaching a certain value. When the mass fraction of the microcapsules increased, the elongation at the break increased first and decreased later. When the core–shell ratio was small and the mass fraction was between 5.0% and 15.0%, the coating had better liquid resistance. When the core–shell ratio was 0.67:1 and the mass fraction was 10.0%, the overall property of the coating on the Basswood was the best. The technology of microencapsulation provides a technical reference for the waterborne primer with self-repair qualities on the surface of wooden products.

The nuances of toning and wood dyeing in the process of creating the original wooden sculptures

  This article states that the ways to improve the decorative qualities of wood have been known to mankind since ancient times. The techniques of woodworking material have improved over years. The author underlines the importance of proper choice of finishing materials, as it intended to preserve the cultural objects, as well as produce certain aesthetic perception. Therefore, the choice of materials is substantiated by the nature of the wood and the work performed, as well as by the author's plan and conceptual idea. The article discusses the key methods of wood finishing in the process of creating wooden sculptures. The author lists the main types of wood finishing, as well as the original techniques. It is noted that there are various technologies for giving a wood surface a different color. Description is given to such methods as fire-treatment and waxing of wooden surface; as well as to the original techniques of treating wood damaged by the bark beetle or exposed to fire. It is claimed that proper firing gives wood strength and resistance, protecting it from various influences and significantly extending its durability. Special attention is given to the wood ash treatment, and how this ancient technology can be applied in modern wooden sculpture. The recommendations are given for proper selection of applicators that contribute to quality dyeing of wooden surfaces.

Monitoring the Restoration of a Seventeenth-Century Wooden Artwork Using Laser-Induced Fluorescence and Digital Image Analysis

The present paper is aimed at demonstrating the capabilities of digital image analysis (DIA) to support conservation of painted artwork. Laser-induced fluorescence (LIF) imaging has been usually used in the diagnosis of wall paintings. In this case, LIF is applied to the case study of a painted wooden canopy, and most successful data processing techniques are presented in the discussion of results. The Jesús del Gran Poder canopy, completed by Francisco Ruiz Gijón in 1692, is an oil panel painting on wood. Eight panels of the canopy have been study by LIF. This technique is capable of remotely acquiring hyperspectral images operating in fluorescence mode following ultraviolet laser excitation. LIF spectra combined with principal component analysis, spectral angle mapper, and DIA provide a chemical mapping of the treated wooden surface of the panels. Besides, LIF spectrum is as a fingerprint of the panels that allows stablishing differences between them. LIF imaging analysis has proven to be a very useful tool for mapping retouching work, tracking previous restorations, and detecting chemicals on the wood in order to monitor restorations.

Accuracy of the pneumatic follower for the wooden surface quality assessment

Wooden or wood-plastic composite surfaces are often valued for their aesthetic appearance and the quality of the surface. Independent from the technology, the surface features may be assessed using typical roughness parameters. In this paper, a pneumatic non-contact method is proposed. Despite certain limitations in surface characteristics measurement, air gauges proved to be a good tool for wooden surfaces, much cheaper than the laser profilometers. In the current research, a novel non-contact air gauge was combined with a slider to eliminate the influence of the asperities of higher order (waviness) and to protect the wooden surface from being damaged by the measuring nozzle. The measurement signal was used to control a follower that kept constant distance between the surface and the nozzle edge. The measuring speed was set at 0.8 mm/s, and the back-pressure was measured with accuracy of 0.01 kPa with real time acquisition. A series of measurements was taken, and the results were compared with the ones obtained from Perthen S8P profilometer (contact measurement) and WYKO NT 1100 interferometer microscope.

FRICTION COEFFICIENT OF MUNICIPAL SOLID WASTE COMPONENTS

Engineering properties of materials includes coefficient of friction (COF) which are basic in design performance of engineering systems. The COF can be considered as very important in design of handling tools. Various types of handling tools and equipment are used at various stages of disposal and treatment of MSW and COF is one critical property. This paper presents estimate of COF of municipal solid waste components. The components of the municipal solid waste are paper, plastic, organic and others. The estimation of the COF was done using an inclino-tribometer. Waste from 16 sample locations were used with 6 surfaces which are considered to be of relevant. It was estimated that Formica surface has the least COF values and range from 0.269 and 0.312 with ‘others’ – formica surface tribosystem being the least. It was also found that paint application on wooden surface with oil paint would increase COF as compared to applying emulsion on same wooden surface. The study pointed out that polishing with vanish is the best way to reduce COF in wood surfaces. It was also observed that painting metal surfaces with oil paint will increase the COF than when the same metal was left unpolished or unpainted.