scholarly journals The impact of the top coating on the mechanical properties of lacquered wood surfaces

2012 ◽  
pp. 87-100
Author(s):  
Milan Jaic ◽  
Tanja Palija

This paper investigates the impact of the top coating on the basic mechanical properties of a lacquered surface, including indentation hardness, scratch resistance and abrasion resistance. Three types of the top coating were used, including a 2K polyurethane coating, a 2K acrylate-isocyanate coating and a 2K alkyd-urethane coating. Samples of two wood species, spruce (Picea abies Karst.) and oak (Quercus robur L.), were used in this study, in order to determine whether the wood species, which is not in direct contact with the top coating, has an impact on the mechanical properties of a lacquered surface. The samples coated with a 2K acrylate-isocyanate coating showed the highest values of indentation hardness, in the samples of both wood species (1.34 N for spruce; 1.4 N for oak). The samples coated with a 2K alkyd-urethane coating showed the highest values of scratch resistance (20 N for both wood species) and abrasion resistance (mass loss of 480 mg after 700 cycles for both wood species). The results have shown that the wood species does not affect the value of indentation hardness, scratch resistance and abrasion resistance of a lacquered surface.

2010 ◽  
pp. 7-23
Author(s):  
Milan Jaic ◽  
Jovan Dobic ◽  
Tanja Palija

This paper presents the research of influence of sanding, staining and the use of polyurethane and acrylic coating on the adhesion, scratch resistance and abrasion resistance of the coating. Objective was to determine the most important mechanical properties of lacquered surfaces, considering the application of Paulownia elongata and Paulownia fortunei, by using different systems of surface finishing. Cross cut method was used for measurement of adhesion. More accurate view of coating adhesion was obtained by measuring the scratch resistance. Abrasion resistance was tested by the method of free falling of abrasive particles. The applied system of sanding had no effect on the examined mechanical properties. Stained samples lacquered with PU coating showed better adhesion to the non-stained samples. Impact of staining on scratch resistance is not established. Stained samples showed greater resistance to abrasion for both wood species. Samples lacquered with PU coating showed the higher values of mechanical properties compared with samples lacquered with UV acrylic coating. Application of PU coating for surface finishing of Paulownia elongata and Paulownia fortunei is more adequate than the application of UV acrylic coatings, from the point of scratch resistance and abrasion resistance.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5380
Author(s):  
Jingda Huang ◽  
Peihao Cai ◽  
Mengmeng Li ◽  
Qiang Wu ◽  
Qian Li ◽  
...  

Complex preparation methods and weak mechanical properties of superhydrophobic coatings hinder their applicability. To address these problems, cellulose nanofibers (CNFs) were used as structural materials to augment the roughness properties, while polydimethylsiloxane (PDMS) was used as the adhesive. Based on the results of previous studies, superhydrophobic coatings with good mechanical properties can be prepared by spraying the mixture onto a substrate surface; herein, the mixture comprised modified CNFs and PDMS. The resulting coating possessed excellent superhydrophobicity, which allowed a maximum water contact angle (WCA) of 158°. Furthermore, it exhibited great knife-scratch-resistance properties and good abrasion performance, which was evaluated by abrading with 800-grit sandpaper for 19 cycles (abrasion length of 380 cm) under a 100 g load. Based on the simple operation and abrasion resistance, the coating shows great potential for practical application.


Author(s):  
Ю.И. Головин ◽  
А.И. Тюрин ◽  
А.А. Гусев ◽  
С.М. Матвеев ◽  
Д.Ю. Головин ◽  
...  

The paper presents the results of mechanical properties scanning by means of nanoindentation across the annual growth rings of deciduous trees wood, small-leaved lime (Tilia cordata) and common oak (Quercus robur) in particular. Significant variations in microhardness H and Young’s modulus E radial dependencies have been found for any of the studied species. Results can be useful 1) to amend the understanding the nature of macromechanical properties of various wood species and to reveal the details of their formation depending upon microstructural characteristics, 2) to optimize the technologies of growing, reinforcement and subsequent usage of the wood, 3) to develop new independent methods in dendrochronology and dendroclimatology


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2430 ◽  
Author(s):  
Mariusz Krupiński ◽  
Paulina Ewelina Smolarczyk ◽  
Mirosław Bonek

The scope of the work covers the development of the relationship between the chemical composition of surface-modified copper and the diffusion of alloy elements as well as the microstructure and mechanical properties. This article presents the impact of laser alloying with titanium and silver powders on the microstructure and mechanical properties of copper. In order to investigate the phenomena occurring during the laser alloying process, microstructural studies were performed using scanning electron microscopy (SEM), optical microscopy, and energy dispersive x-ray spectroscopic (EDS) analysis of the chemical composition in micro-areas. In addition, to test the properties of the resulting alloy, abrasion resistance, hardness measurement at low loading force, and conductivity measurements were performed. As a result of alloying with Ag and Ti powders, three distinct zones were indeed recognized: re-melting zone (RZ), diffusion zone (DZ), and heat affected zone (HAZ). The surface modification that results from laser alloying increases the hardness as well as the abrasion resistance of the material. Overall, it was found that laser alloying with Ti powder increased the strength of the copper surface layer due to the formation of intermetallic phases (Cu3Ti2). It was also found that laser alloying with Ag powder changed the mechanical properties of the surface layer due to the solid solution strengthening.


Author(s):  
Ada Traumann ◽  
Merje Beilmann ◽  
Diana Tuulik

The purpose of this paper was to evaluate the impact of maintenance to some mechanical properties of coated fabrics. Polyester is often used for outerwear because of its high durability. Coating application enhances several physical – mechanical properties of fabric. The reverse side of the test fabrics were laminated with a thin layer of the membrane to ensure complete water resistance. Since the micro-pores are sufficiently small, they will not let water through, but they let vapour through from inside to outside. It makes these kind fabrics vapour-permeable and therefore very comfortable for wearing. Although we can damage the micro-pores in the fabric very quickly whether by false maintenance mode at home for washing or drying. Test fabrics of this study were chosen from kid`s outerwear collection. Kids are good for testing of ready to wear garments but this time, the emphasis was on laboratory tests of basic fabrics. The aim of this study was to test the outer fabric under the conditions of domestic care and thereafter to carry out tests on abrasion resistance and tearing of cared fabrics.  


2021 ◽  
Vol 326 ◽  
pp. 157-165
Author(s):  
Paulina Smolarczyk ◽  
Mariusz Krupiński ◽  
Wojciech Pakieła

The scope of the work covers the development of the relationship between the chemical composition of surface-modified aluminium and its mechanical properties. This article presents the impact of laser alloying with ZrO powder on the microstructure and mechanical properties of pure aluminium. In order to study the phenomena occurring during the laser alloying process, microstructural studies were carried out using optical microscopy. Additionally, the properties of the obtained alloy were tested - abrasion resistance and hardness measured at low load force. As a result of the alloying process, three distinct zones were identified: the remelting zone (RZ), the diffusion zone (DZ) and the heat affected zone (HAZ). The surface modification resulting from laser alloying increases the hardness and abrasion resistance of the material.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2323
Author(s):  
Yubing Du ◽  
Zhiqing Zhao ◽  
Qiang Xiao ◽  
Feiting Shi ◽  
Jianming Yang ◽  
...  

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.


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