Introduction: Given the increase in the world's population and the subsequent increase in demand for wood and wood products, the high cost of wood, limited forest resources, damage to forests, the environment, and human health, today it is very important to create solutions to meet the needs of human societies with the aim of creating sustainable development, reducing the consumption of forest resources, and preserving the environment for human health. Therefore, this research investigated the possibility replacement and using environmentally friendly cross-linked polyethylene foam, free of harmful gases and recyclable, in the manufacture of wooden sandwich panels (A composite wood product widely used in various industries such as wood and furniture, construction, etc.).
Materials and Methods: This study was experimental and performed on a lab scale. The test sandwich panels were made from three types of medium-density fiberboards and 3 mm thickness (with natural beech veneer, synthetic melamine veneer, and no veneer) as skin and from cross-linked polyethylene foam with 30 mm thickness and 30 kg/m³ density as core (with the use of polyvinyl acetate glue). Then, were measured properties of bending strength, modulus of elasticity, compressive strength, impact strength, and also water absorption of 2 and 24 hours. The results were analyzed with an ANOVA test.
Results: The results of ANOVA showed the effect of the skin veneer type on the mechanical properties (bending strength, modulus of elasticity, compressive strength perpendicular to the surface) and the physical properties (water absorption 2 and 24 hours after immersion in water) of the sandwich panels made at a 5% probability level was significant, but the effect of skin veneer type on impact strength is not significant. Results showed that the use of fiberboard with natural veneer on the skin of the sandwich panel has created the highest mechanical strength. The results also showed that the use of fiberboard with synthetic melamine veneer reduces the water absorption percentage of 2 and 24 hours of the made sandwich panel.
Discussion: The results showed that it is possible to make sandwich panel with cross-linked polyethylene foam. The cross-linked polyethylene foam is environmentally friendly and free of harmful gases, thus providing the manufacture of sandwich panel with an environmentally friendly characteristic. The manufacture of sandwich panels with non-wooden cores such as cross-linked polyethylene foam, by reducing the need for wood or forest resources that are low in Iran and the world, has led to sustainable development, preservation of forest resources, preserving the environment and human health, as well as reducing the problems of providing raw materials for the wood and furniture industries and composite wood products. It is also economically viable. On the other hand, due to the very high physical and mechanical properties of cross-linked polyethylene foam, its use in the core of a wood sandwich panel creates a wide variety of functionalities for the made sandwich panels. The various properties of cross-linked polyethylene foam, such as thermal strength (against heat and cold), chemical strength, strength to the growth of fungi and insects, non-toxicity, proper dimensional stability, moisture and sound insulation, compatibility with the environment and being free from harmful gases, quick and easy installation, and ease of transportation, have led to its many applications in various industries. These applications include: construction industries (insulation of floors, walls, shed roofs, window sealing, etc.), automotive, home appliances, packaging, furniture (sofas and bedroom service), etc. In addition to the aforementioned applications, cross-linked polyethylene foam can be used in the manufacture of sandwich panels used as interior space partitions, Interior doors of the building, wall cupboard doors, covering interior common walls, etc.