Study on the Effect of Impregnation Process on Physical and Mechanical Properties of Chinese Fir LVL

Laminated veneer lumber (LVL) was manufactured from Chinese fir, which had been impregnated with laboratory prepared low-molecular-weight water-soluble phenol formaldehyde (PF) resin. The effects on the mechanical and physical properties of the LVL were investigated which made from veneer that had been subjected to various levels of the resin treatment. The results showed that either under conditions of normal temperature and pressure, or at increased pressure, the weight gain would increase with the impregnating time. Under the same impregnation technology, along with the increase of resin concentration, dry weigh gain increased, wet weight gain first increased and then decreased. Density of LVL increased, TS reduced, MOR and MOE first increased and then decreased as the weight gain increased.