WOOD PARTICLEBOARDS REINFORCED WITH THERMOPLASTICS TO IMPROVE THICKNESS SWELLING AND MECHANICAL PROPERTIES

ABSTRACT The manufacture of forest products with high physical and mechanical properties contribute to the development of the forest industry in obtaining more resistant products with potential in the construction sector. In this context, to contribute to the study of reconstituted panels this article discusses the manufacture of panels reinforced with recycled thermoplastics (WPC), which had as raw material sawdust of Pinus caribaea and as recycled thermoplastics polyethylene terephthalate, low-density polyethylene and polypropylene. The panels were obtained by extrusion and developed in four treatments with different proportions of raw material. Thickness swelling rates of the manufactured WPC were evaluated by immersing them in water at room temperature and monitoring thickness changes for several weeks. A swelling model developed by Saeed Kazemi Najafi was used to study the thickness swelling process of WPC. The WPC were characterized by thickness swelling, apparent density, static blending, longitudinal compression and tensile strength. The treatment with 50% sawdust and blend of all thermoplastics (T5) showed a tendency to reduce the thickness swelling because it absorbs 0.28% of water and maintains the balance of water absorption in 16.2% the apparent density was 1206 kgm-3. For the mechanical properties, the static blending, longitudinal compression and tensile strength are around 24.6, 142.4 and 32.8 MPa, respectively. These characteristics make a treatment the best response. Hence, is suggested this board be used for structural applications, such as interior or exterior walls, since the water absorption index is low and high mechanical properties allow being more resistant.摘要 制备具备优异物理与力学性能的林产制品，有助于推动林业产业发展，可获得在建筑领域具有应用潜力的高耐久产品。在此背景下，为促进重组板材的研究，本文探讨了回收热塑性塑料增强型板材（Wood Plastic Composite, WPC）的制备工艺：以加勒比松（Pinus caribaea）锯末为基材原料，以聚对苯二甲酸乙二醇酯、低密度聚乙烯和聚丙烯作为回收热塑性塑料组分。该类板材通过挤出工艺制备，共设置四组不同原料配比的处理方案。通过将制备完成的WPC置于室温水中浸泡，并连续数周监测其厚度变化，以此评估板材的厚度膨胀率。本研究采用Saeed Kazemi Najafi提出的厚度膨胀模型，分析WPC的厚度膨胀过程。研究对WPC的厚度膨胀率、表观密度、静曲强度、纵向抗压强度与抗拉强度进行了性能表征。当原料配比为50%锯末与全部三种热塑性塑料共混时（处理组T5），板材表现出显著的厚度膨胀抑制效果：其吸水量为0.28%，平衡吸水率达16.2%，表观密度为1206 kg·m⁻³。力学性能方面，该处理组的静曲强度、纵向抗压强度与抗拉强度分别约为24.6 MPa、142.4 MPa与32.8 MPa。上述性能使该处理组成为综合性能最优的方案。因此，建议将该板材应用于建筑结构场景，如内墙与外墙：其吸水率较低且力学性能优异，可满足高耐久使用需求。