Effect of Glue Spreading Methods on the Properties of Laminated Strand Lumber with Different Densities
The effects of glue spreading methods on the density profile,resin distribution,water resistance,and bending properties of laminated strand lumber(LSL)with different densities were investigated using Pinus radiata strands and phenolic resin as raw materials.The results indicated that the resin content on the surface of the strand and the penetration depth of the resin into the strand were different when two spreading methods were applied.The resin prepared by the dipping method penetrates the strands,which was conducive to the reinforcement of the strands.The surface on the strands prepared by the spraying method had higher resin content,which was conducive to the formation of a good gluing interface between the units.As the density elevated from 0.80 g/cm3 to 1.00 g/cm3,the glue spreading methods significantly affected the bending properties and water absorption of LSL,while there was no significant effect on the thickness swelling rate of LSL.When the density was 1.00 g/cm3,the LSL prepared by the dipping method had a higher MOE(19.9 GPa).Nevertheless,it was susceptible to delamination within the adhesive layer situated between the strands during the water resistance test.The LSL prepared by spraying method had a higher MOR(126.8 MPa),and the glue layer between the strands was less prone to delamination in the water resistance test.
laminated strand lumber(LSL)glue-dippingglue-sprayingwater resistancebending propertydensity profileadhesive distribution
国家科技期刊平台
NSTL
万方数据
维普
