The Effects of Liquid Nitrogen and Impregnation on Physical and Mechanical Properties of Fir Wood

Aim of study: To improve and develop the wood impregnation process. Therefore, the aim was to use liquid nitrogen application as a new method to determine its effects on impregnation and mechanical properties Area of study: Fir wood (Abies bornmülleriana Mattf.), widely used in the forest industry, was selected for the study. Liquid nitrogen pretreatment and impregnation methods were applied. Material and method: Fir wood samples prepared according to relevant standards were exposed to liquid nitrogen for 15 minutes, 90 minutes, and 6 hours. The samples were impregnated with diammonium sulfate using brushing, short-term and long-term immersion, and pressure methods. Retention levels were measured, and flexural strength and modulus of elasticity tests were conducted to evaluate the effects on mechanical properties. Main results: As a result of the study, the retention rate of the samples increased with each application of liquid nitrogen. Differences in flexural strength and modules of elasticity were detected due to the increased retention properties of liquid nitrogen application. Research highlights: Increasing the retention rate with liquid nitrogen application increased the material's lifespan and durability. It can be used as an alternative method for difficult-to-impregnate materials.