Drying Urea Formaldehyde Resin–Modified Chinese Fir for Mining Supporting Materials

Abstract

Abstract The drying characteristics of urea formaldehyde (UF) resin–impregnated Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) wood were determined by the 100°C-test method and scanning electron and fluorescence microscopies to predict an optimal drying schedule. Compared with the untreated sample, the UF resin–impregnated Chinese fir wood presented a lower grade of initial checks and a faster initial drying velocity, but a higher grade of internal checks and a slower drying velocity at the later stage. The average drying velocity of the UF resin–impregnated wood was 38.9 percent lower than that of the untreated sample. The predicted drying schedule was applied to the UF resin–impregnated wood and the resulting grades of the drying characteristics were in good agreement with the required national standard values. The resulting dried UF resin–modified composite would become a potential candidate for a shallow depth rock mining supportive system with its stable mechanical performance.