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EN
This study investigates the effects of different formaldehyde scavenger (FS) ratios on the physical, mechanical, and chemical properties of fiberboard composites. Experimental analyses included measurements of thickness, density, modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB), shear strength (SS), moisture content, thickness swelling (TS), water absorption (WA), and formaldehyde emission (FE) levels. The results indicate that an increase in the FS ratio leads to a significant decline in mechanical properties. Specifically, MOR, MOE, and IB values decreased by 17.97%, 15.65%, and 16.33%, respectively. Changes in TS and WA were also observed, with TS increasing by up to 22.68% and WA decreasing by as much as 16.90%. In terms of formaldehyde emissions, a significant reduction was observed as the FS ratio increased. At a 15% FS ratio, formaldehyde emissions decreased by 43.24%, which is considered a positive outcome in terms of environmental and health impacts. Overall, the use of FS in specific ratios reduces FE while causing certain reductions in mechanical properties. These findings highlight the importance of optimizing FS usage for the production of low-FE fiberboards.
EN
Calcium lignosulfonate (CLS) (C20H24CaO10S2) is widely used in various industries today, including wood, construction, food, agriculture, and textiles. There are currently few studies on the addition of CLS chemicals to various fiberboards. This study was designed to explore the outcomes of the interaction between CLS and the boards, with the aim of expanding the potential applications of this chemical. We incorporated CLS at varying percentages (6%, 8%, and 10%) as an adhesive additive in high-density fiberboard (HDF) produced using urea-formaldehyde (UF) resin in a laboratory setting. We assessed its impact on several physical properties - thickness swelling (TS), den-sity, and water absorption (WA) - and mechanical properties: modulus of rupture (MOR), internal bond strength (IB), modulus of elasticity (MOE), and surface soundness (SS). A control group was created using prepared boards, enabling the comparison of results between boards made with and without CLS additives. According to the results of a multivariate analysis of variance, the CLS per-centage showed no significant effect on density, MOE, and SS. However, it significantly influenced TS, WA, IB, and MOR, resulting in reductions of 4-12% for SS, 6-12% for MOR, and 2-22% for IB, while increasing TS by 20-130%, WA by 25-84%, and MOE by 1-3%. It was observed that the use of CLS led to differing results in the tests conducted on the produced HDF materials.
EN
In this study, solvent-based yacht varnish, stone varnish, and waxy varnish were applied in two coats using a brush, following industrial application standards, to the surfaces of the following tree species: black alder (Alnus glutinosa L. Gaertn.), curupay (Anadenanthera macrocarpa Benth.), iatandza (Albizia ferruginea), lemon (Citrus limon (L.) Burm.), loquat (Eriobotrya japonica L.), magnolia (Magnolia grandiflora L.), plane (Platanus orientalis L.), sucupira (Bowdichia nitida Benth.), and hornbeam (Carpinus betulus L.). Subsequently, the color parameters (b*, C*, L*, a*, ho, ΔE*, ΔH*, Δb*, ΔC*, Δa*, and ΔL*) of the varnish layers were compared with those of the untreated surfaces. The results of analysis of variance revealed significant differences in all color parameters. Decreases in L* values and increases in a* values were observed for all wood types when treated with three different varnishes. Additionally, in plane, black alder, and hornbeam wood, application of all varnishes resulted in increases in b* and C* values, with decreases in ho values. In sucupira wood, however, decreases were observed in b*, C*, and ho values with the application of all three varnishes. It was observed that a single type of varnish yielded different results on different wood types. This finding was attributed to the different types of resins present in the varnish types used in the study, which resulted in varying outcomes.
EN
An investigation was carried out without the use of thermal treatment to determine whether waste oils have color-altering effects on wood material surfaces. Waste vegetable oils (walnut, sunflower, corn, and olive) were applied to the surfaces of wood materials from ayous (Triplochiton scleroxylon K. Schum), fukadi (Terminalia amazonia), guatambú (Balfourodendron riedelianum (Engl.) Engl.), mahogany (Swietenia mahagoni (L.) Jacq.), and rengas (Gluta renghas L.) tree species. Subsequently, a control group was established, and experimental samples were compared. Changes in color parameters (L*, ∆a*, C*, ∆L*, a*, ∆b*, ho, ∆H*, b*, ∆C*, and ∆E*) were investigated. The results of multivariate analysis of variance for color parameters (C*, ho, L*, a*, and b*) were found to be statistically significant. A decrease in ho and L* was observed for all wood types and waste oils. On the other hand, a* and b* values increased and C* values decreased in guatambú and ayous wood on application of all waste vegetable oils. However, in the case of mahogany and rengas wood, a* and b* values decreased while C* values increased.
EN
Linden wood is used in the making of musical instruments, agricultural hand tools, and in the furniture sector. In this study, the changes in glossiness (parallel (//) and perpendicular (⊥) to the fibers at 20o, 60o, and 85o), the pull-off adhesion test, color parameters (CIEL) and pendulum hardness (König method) of two different UV curable varnishes applied to linden (Tilia tomentosa Moench.) according to industrial application techniques and exposed to artificial weathering were investigated. According to the research results, while L*, ΔH*, and ho decreased with increasing weathering time in both varnish layers, ΔC*, b*, ΔE*, a*, and C* rose. The pendulum hardness grew for Method B but dwindled for Method A. A decrease was found in the adhesion tests for both varnish methods after artificial weathering. The glossiness was generally reduced due to artificial weathering for all the angles and for both directions, with the exception of 85º in Method A. The variance analysis and homogeneity groups showed that the changes in the adhesion, pendulum hardness, L*, a*, ho, C*, perpendicular and parallel to the fibers for 60o and 85o were found to be significantly different with artificial weathering for both methods.
EN
The importance of UV-curable coatings is currently increasing. In the parquet industry, where UV systems are applied, it is beneficial to investigate new tree species as potential raw materials. This study was carried out to determine the effect of accelerated ageing on some surface properties of hackberry (Celtis australis L.) wood treated with UV system parquet varnish. UV system parquet varnishes were applied to hackberry wood surfaces in three and five layers, according to the requirements of industrial applications. The varnished surfaces were then exposed to UV rays for 252 and 504 h using UVA-340 lamps in a QUV ageing device. Glossiness, colour parameters, pendulum hardness and adhesion strength (pull-off) (MPa) were determined for the coated samples before and after ageing, and the results for the aged and unaged test samples were compared. Analysis of variance showed that the results were significant for all tests. The results for all tests varied by ageing time.
EN
Scots pine, beech, and oak are the most important tree species in the furniture sector in Turkey. In this study, the aim is to determine pendulum hardness (König method) values against artificial aging in water-based varnishes applied to some wood species after heat treatment. For this purpose, Scots pine (Pinus sylvestris L.), sessile oak (Quercus petreae L.), and Eastern beech (Fagus orientalis L.) wood samples were heat-treated at 190°C for 2 h and at 212°C for 1-2 h according to the ThermoWood method. Later, one- and two-component water-based varnishes (WBVOne-comp. and WBVTwo-comp.) were applied to the material surfaces in accordance with the manufacturer’s recommendations for layer thickness for industrial applications. The materials were exposed to UV light using UV-A 340 nm fluorescent lamps for 144, 288, and 432 h in a QUV accelerated weathering tester. After these weathering periods, pendulum hardness values were determined. It was found that hardness values increased after weathering, and that WBVTwo-comp. gave higher values than WBVOne-comp..
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