松桉轻质刨花板内结合强度及其破坏模式对比  

Comparative on internal bond strengths and failure modes of lightweight particleboards of pine and eucalyptus

作　　者：秦理哲 黄腾华[1] 雷福娟[1] 胡拉 王军锋[1] 宋恋环 QIN Lizhe;HUANG Tenghua;LEI Fujuan;HU La;WANG Junfeng;SONG Lianhuan(Guangxi Forestry Research Institute,Nanning 530002,China;College of Chemistry and Chemical Engineering,Guangxi University for Nationalities,Nanning 530008,China)

机构地区：[1]广西壮族自治区林业科学研究院,南宁530002 [2]广西民族大学化学化工学院,南宁530008

出　　处：《林业工程学报》2022年第1期66-71,共6页Journal of Forestry Engineering

基　　金：国家重点研发计划子课题(2018YFD0600301);广西自然科学基金项目(2018GXNSFBA281108)。

摘　　要：人造板“轻质化”是近期我国木材加工行业的重要发展方向之一,而对于轻质刨花板力学性能及其破坏模式的深入分析可为其开发利用提供重要依据。以松木和桉木为木质原料,选用聚氨酯发泡胶黏剂制备全松木、全桉木和松桉混合3种具有不同原料组成的轻质刨花板,对比分析其内结合强度和破坏模式,并从破坏断面形貌和刨花表面润湿性两方面进行了深入探讨。结果表明:平均密度为540 kg/m^(3)的轻质刨花板中,全松木刨花板的平均内结合强度(0.26 MPa)显著小于全桉木刨花板(0.38 MPa)和松桉混合刨花板(0.35 MPa)。内结合强度测试中:全桉木刨花板的木材破坏区域占比最大,为(60.9±24.9)%;全松木刨花板最小,为(18.3±16.3)%;松桉混合刨花板介于两者之间,为(44.3±26.7)%。全桉木刨花板的破坏断面平整度较小,算术平均粗糙度(R_(a))值为(12.75±4.98)μm;全松木刨花板的破坏断面平整度较大,R_(a)值为(2.60±0.75)μm。3种刨花板均表现为胶层和木材混合的破坏模式,但在破坏断面平整度、木材破坏区域占比上具有明显差异,是其内结合强度表现出差异的重要原因。Reducing the density of wood-based panels to obtain lightweight products is beneficial to save wood resources and reduce processing energy consumption and transportation costs of products,which has recently become an important wood-based composite production trend in the China s wood industry.The density of particleboards is commonly reduced by selecting low-density raw materials or foaming adhesives and by adding lightweight fillers.For the foaming adhesives,the pore structure inside the adhesive can effectively reduce the density of the particleboards.More importantly,gases expansion during the foaming process can generate pressure to make good contact between the wood particles and the adhesive,which contributes to form a better bonding strength.At present,the process optimization and property evaluation of lightweight particleboards have been widely studied,but limited reports regarding mechanical properties especially failure modes of lightweight particleboards were found in the literature review.An in-depth analysis of the mechanical properties and failure modes of lightweight particleboards can provide an important basis for their development and utilization.In this study,three types of lightweight particleboards(pine,eucalyptus,and pine/eucalyptus)were prepared from particles of pine and eucalyptus wood,and an adhesive of foamed polyurethane.The internal bond strength(IB)and failure modes of the three particleboards were investigated,and their variations were further clarified from the morphology of failure surfaces and surface wettability of wood particles.The results showed that the average density of particleboards was 540 kg/m^(3).The average IB of pine particleboards(0.26 MPa)was significantly lower than that of eucalyptus(0.38 MPa)and pine/eucalyptus(0.35 MPa)particleboards.The IB of pine particleboards met the P1 style requirements in the Chinese standard GB/T 4897-2015,while the IB of eucalyptus and pine/eucalyptus particleboards met the P2 style requirements.In the IB test,the ratio of wood failu

关 键 词：轻质刨花板 内结合强度 破坏模式 破坏断面形貌 刨花润湿性 

分 类 号：TS653[轻工技术与工程]