The Effects of Phenol Formaldehyde Resin Impregnation on the Main Physical and Mechanical Properties of Cunninghamia lanceolata Lumber

To improve the physical and mechanical properties of Cunninghamia lanceolata wood lumber, low molecular weight phenol formaldehyde resin was impregnated into the lumber via a “vacuumpressure” process. The distribution characteristic of resin was investigated in the length and thickness directions. The results showed that the dimensional stability of Cunninghamia lanceolata had increased gradually after impregnating with the 10%, 20%, 30% concentrations of PF resin. The modulus of rupture remained unchanged after it increased from 645 MPa to 75.0 MPa. The modulus of elasticity and hardness were increased by 61%, 275%, 482% and 298%、631%, 738%, respectively. However, the impact toughness of Cunninghamia lanceolata decreased gradually with the increase of weight gain rate of resin. In the length direction, the resin distributes uniformly. In the thickness direction, the content of resin in the edge is more than that in the inside.