Development of cornstarch and tannin-based wood adhesives for interior particleboard production

Abstract

Wood-based panel industry is an important industry that produces wood-based panels such as furniture and parquet, which we frequently use in our daily lives, on an industrial scale. Particleboard is one of the most important products frequently produced in the wood-based panel industry. Particleboard is a composite product. It is made by turning the logs into chips and pressing the formed chips in a hot press by mixing with a thermoset resin. Therefore, the thermoset resin used in particleboard production, as well as the wood raw material, is of great importance in terms of the final properties of the final product. Thermoset resins, which are frequently used in the wood-based panel industry, are based on formaldehyde such as urea formaldehyde and melamine formaldehyde. Cost advantage and high reactivity of formaldehyde-based resins are the most important reasons for their frequent preference. Today, one of the most important problems of the wood-based panel industry is formaldehyde emission. Formaldehyde is classified as a carcinogenic substance and threatens human and environmental health. Therefore, there are formaldehyde emission limits that become more restrictive day by day. Some of the factors affecting the formaldehyde emission of wood-based panels are the formaldehyde found in the natural content of the wood raw material, the type of wood raw material used, and hot press conditions. Apart from these, it is known that one of the most important factors affecting plate formaldehyde emission is formaldehyde-based thermoset resins used as binders. It is known that the formaldehyde content of these resins, which are not involved in polymerization and released, and especially when the urea formaldehyde resin is exposed to moisture and temperature, hydrolysis and release of formaldehyde increase the formaldehyde emission values of the boards. In addition to the fact that formaldehyde-based resins cause formaldehyde emission, they are produced from petrochemical raw materials. Formaldehyde emission caused by formaldehyde-based resins and their synthesis from petrochemical raw materials has pushed the industry and academia to resins that can be synthesized with the use of sustainable raw materials that can be an alternative to formaldehyde-based resins in terms of performance and cost. In the doctoral dissertation conducted in cooperation with Kastamonu Integrated Wood Industry, which is a global power in its sector, and Istanbul Technical University, it was worked on the development of resin formulations containing corn starch - tannin to be used in the production of particleboard suitable for internal applications. Physical and chemical properties of synthesized resins were determined. In order to examine the performances of suitable resin formulations, paticleboard production was carried out in laboratory scale. In addition to the physical and mechanical tests of the particleboards, formaldehyde emission tests were performed. The formaldehyde emission of the produced boards was determined by the perforator method. The physical and mechanical results obtained were evaluated by taking into consideration the particleboards for use in interior applications and their properties standard TS EN 312 standard P2 class limit values. Production of laboratory scale particleboards and physical, mechanical and perforator tests of the produced particleboards were carried out with the support of Kastamonu Integrated Wood Industry R&D department.