Phenolic resin-based adhesives and methods of using same in preparing laminated veneer lumber (LVL)

摘要

Adhesive compositions and methods of using the compositions in the production of laminated veneer lumber (LVL) are disclosed. The adhesive compositions comprise a thermosetting phenol-aldehyde resin having at least one of (A) a number average molecular weight (MSUBn/SUB) of at least about 450, (B) a weight average molecular weight (MSUBw/SUB) of at least about 2000, and (C) a Z-average molecular weight (MSUBz/SUB) of at least about 6000, wherein said MSUBn/SUB, MSUBw/SUB, and MSUBz /SUBare measured using gel permeation chromatography (GPC), a ketone-aldehyde resin cure promoter, and optionally other components (e.g., a tack-promoter or a catalyst). The adhesive compositions minimize or eliminate the art-recognized problems of glue line dryout and steam blowout, associated with LVL manufacture from both low-moisture veneers and high-moisture veneers, respectively. Furthermore, the adhesive compositions provide fast tack-build and curing as well as ultimately good bonding characteristics.