Study On Production Technology Of Reconstituted Decorative Lumber

This paper take the fast-growing poplar Reconstituted Decorative Lumber (RDL) as the object of study, take polyvinyl acetate(PVAc) mixed with urea-formaldehyde(UF)resin adhesive as the experiments material,Through a large number of experiments, attempt to identify the process parameters of the impact on the final product performance.At first, the orthogonal testing method has been used to study the influence of PVAc on the adhesive properties of UF. Different proportion of PVAc mixed with UF resin, taking into account the ambient temperature, the dosage of curing agent on the modified UF resin curing time was studied, and modified adhesive of wetting properties on the surface of poplar veneer was tested, the test results showed that the modifier help to improve the curing properties of UF resin and wetting properties, but also pointed out that the PVAc proportion accounted for 20%, NH4Cl dosage of 2%, citric acid dosage 5% of the modified UF resin adhesive for best results.In addition, the use of Fourier transforms infrared spectroscopy (FTIR), Thermogravimetry differential thermal analysis (TG-DTA) of PVAc/UF mixture of different proportions, analysis attempt to explore the changes from the active group and the curing reaction mechanism. From the TG-DTA and FTIR analysis showed that increasing the dosage of PVAc further reduce the adhesive of curing temperature, the bonding performance has been further improved.RDL has been produced which using PVAc and UF in low temperature condition compared with the the product has been produced under technological conditions of factory, inspects its physical mechanics performance and the bonding performance index. Product using PVAc/UF adhesives target meets the national standards requirements. Comparison of two processes, the product using modified adhesive obtained effective enhancement in performance. Indicating adhesive had been achieved the desired modification and process improvement purposes.The paper also studied three kind of different plans to re-use waste material after sawing the wooden square for the effect on gluing properties and the timber production rate, the result indicated, the MOR, MOE and the peeling strengths performance of three plans to be higher than the LYT1655-2006 request, simultaneously the timber production rate of RDL has been raised by 17%. The paper through the surface roughness and the angle of contact experiment has carried on the confirmation to the above result.