Research On Preparation And Properties Of The Panels Of Bamboo And Jute Reinforced Foam Sandwich Composites

Glass fiber reinforced sandwich composite is widely used in construction industry, especially in mobile house. However, glass fiber has many problems in the production process and after use, such as high energy consumption, harm to humans and pollution of the environment. This can not meet the requirements of environment protection. In recent years, natural fiber has been attracted people’s attention for its wide sources, low-cost and easy to decomposition. It becomes a new trend to research on environment-friendly composite material.Therefore, it is necessary to research on natural fiber reinforced composite material as sandwich panel. At present, there are literatures use bamboo as a reinforcements, but most of them concentrated in bamboo fiber, which is high cost and not able to use in civilian products. Bamboo structure is uneven and easy to split. Bamboo and jute are used as reinforcements to prepared panels of sandwich composite.Firstly, the effect of alkali treatment on bamboo and jute tensile strength is compared. Found that the tensile elastic modulus and the tensile strength of bamboo, which is treated in15%dilute alkali after20minutes, are increased by50.5%and12.5%. The tensile strength of the jute, which is treated in5%dilute alkali after60minutes, improved slightly. The elongation at break of the jute improved significantly. Then, four layer programs are designed, to understand the impact of alkali treatment on the interface of natural fiber reinforced composite. Vacuum assisted resin transfer molding(VARTM) is used to make a composite panel. The results of tensile and bending properties of panels made of alkali treatment only bamboo or only jute show that, the tensile property is improved a bit more. The bending load and bending strength are small,and significant stratification in the bending test. The tensile strength, flexural strength and bending loads of panels made of bamboo and jute after alkali treatment are the greatest, and no obvious stratification in bending test. Meanwhile, on both sides of the panel to load bending load, the bending strength is different. Way that layer will affect the performance of the composite material plate. Secondly, the one-step and two-step molding process are commonly used to make sandwich composite, but most of the literatures only use one method. There is no comparison to the two molding process, which can not determine the difference between the two products prepared by different molding processes. This paper using the same reinforced material, that is, bamboo and jute after alkali treatment. one-step and two-step molding process are used to prepare bamboo and jute reinforced sandwich composite materials. Tensile shear properties, tensile properties of sandwich panel and bending properties of core are tested. Found that the tensile shear strength of one-step is higher than two-step78.62%.Tensile properties, bending properties and shear performance of one-step are higher than two-step’s more than doubled. Thus, the performance of one-step sample is better.Finally, preparing bamboo and jute reinforced sandwich composite and glass fiber cloth reinforced sandwich composite use one-step molding process. The properties of sandwich composite materials that separately using different reinforcements were comparison analyzed. The results showed that tensile strength, bending strength, shear strength of the sample with bamboo and hemp reinforced composite sandwich structure can achieve the sample with glass fiber cloth reinforced sandwich composite structure of70.66%,73.86%,80.85%. However, bamboo and jute are natural fibers. They are renewable, non-toxic, easy to break-down and contribute to environmental protection.