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1.
Materials (Basel) ; 16(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37687422

RESUMO

Wood-plastic composites (WPCs) represent composite materials that employ shredded wood combined with a thermoplastic substance, such as polylactic acid (PLA), to establish structural cohesion within the product profile. This amalgamation of materials results in a robust structure designed to fulfill specialized roles under the influence of pressure and temperature. Given the nature of the constituent materials, the resultant product can be classified as a biocomposite. The creation of such biocomposites entails a rigorous process necessitating the fine-tuning of specific parameters and suitable technologies. The foundational materials employed in this process must be both natural and biodegradable. However, it is noteworthy that natural components like fibers exhibit anisotropic behavior, wherein their mechanical attributes are contingent on the direction of the applied force. Consequently, predicting their performance during biocomposite production proves challenging. The principal objective of this study was to conduct a comparative analysis of wood-based composites incorporating PLA thermoplastic binding agents. The intention was to discern variations in density profiles arising from distinct measurement methodologies. Two measurement methods were used for the measurement: X-ray and spectrum desaturation. Additionally, the study sought to investigate the impact of introducing PLA additives at 25% and 50% concentrations on the fabrication of WPC from wood chips. The properties of these composites were assessed by considering the inherent traits of the composite materials.

2.
Materials (Basel) ; 16(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37687524

RESUMO

The mechanical strength of wood from Scots pine (Pinus sylvestris), European larch (Larix decidua), and Norway spruce (Picea abies) was studied using static compression tests. The material was exposed under constant soaking in water with salinity of 7‱. The liquid mix was prepared according to a value roughly equivalent to the average salinity along the entire length of the Baltic Sea. The mechanical strength and quality of the raw material were determined using a sea salt saturation test, which determined the adhesion of the raw material to the extrusion process (permissible stress). An investigation was conducted to determine the physicochemical parameters of the material that was tested. It was investigated how much mineral compounds were absorbed over four cycles lasting a total of six weeks during the test. According to the statistical analysis, the chemical composition of wood and the presence of salts and mineral compounds correlated with its mechanical strength. An important part of the study focused on examining the factors affecting the construction of coniferous wood structures. The preparation of the raw material correctly can provide information on how the material can be protected during exposure to specific environmental conditions for longer.

3.
Materials (Basel) ; 16(8)2023 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-37109820

RESUMO

In this paper, the differences in mechanical strength tested during the static tensile and compression test of Scots pine (Pinus sylvestris L.), European larch (Larix decidua) and Norway spruce (Picea abies) wood exposed to continuous soaking in water with a salinity of 7‱ were determined. The value of salinity corresponded to the average salinity on the Polish Baltic coast. This paper also aimed to examine the content of mineral compounds absorbed during four cycles of two weeks each. The essence of the statistical research was to identify the effect of the mineral range compounds and salts depending on the mechanical strength of the wood. Based on the results of the experiments, it can be concluded that the medium used has a specific effect on the wood species' structure. The effects of soaking on the wood parameters depend obviously on the type of wood. A tensile strength test of pine, as well as the tensile strength other species, was enhanced by incubating it in seawater. A native sample's initial mean tensile strength was 82.5 MPa, which increased to 94.8 MPa in the last cycle. It was found that the larch wood had the lowest tensile strength difference (9 MPa) of the woods studied in the current study. Four to six weeks of soaking was necessary to notice an increase in tensile strength.

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