引入双螺杆磨浆法,采用啮合同向双螺杆磨浆机,将高压蒸煮处理(0.2 MPa, 保压10、30、50 min)的木片(长16～50 mm,宽10～25 mm,厚3～8 mm)在不同设备参数(反向螺旋槽口宽度12、16、20 mm)下进行挤榨加工制得细长状单元,研究了单元形态和表面特征,并将挤榨单元制成人造板。结果表明:采用双螺杆磨浆法可将经高压蒸煮处理的木片成功解离为细长状挤榨单元,其形态与普通TMP纤维有显著区别,挤榨单元长度大部分分布在10 mm以内,对应3个槽口宽度的挤榨单元平均长度分别为4.45、5.08和6.18 mm。双螺旋磨浆机的设备参数对挤榨单元的形态具有显著影响,在12～20 mm反向螺旋槽口宽度条件下,木片解离单元长度基本控制在2～10 mm。挤榨单元人造板性能优异,其吸水厚度膨胀率、内结合强度、静曲强度、弹性模量等指标均达到或超过相关的国家标准值,与普通刨花板和中密度纤维板相当。A new slim wood unit was made by squeezing poplar wood chips with a twin-screw pulping machine. The chips with the size of(16-50)mm×(10-25)mm×(3-8)mm were pre-softened by high pressure steam heating at 0.2 MPa for 10, 30, and 50 min, respectively. Three reverse screw rabbet width of the twin-screw pulping machine was tried, i.e., 12, 16, and 20 mm. The morphological and surface characteristics of the squeezed units of poplar wood chips were investigated, which were evidently different from traditional thermal-mechanical pulping fibers. Results showed that heated poplar wood chips could be squeezed into slender units with twin-screw pulping method. The shape of the units was evidently different from traditional TMP fibers. Most squeezed units were shorter than 10 mm, and the average length were 4.45 mm, 5.08 mm and 6.18 mm, respectively, for the three reverse screw rabbet width. The machine parameters had significant influence on the shape of squeezed units. With 12-20 mm reverse screw rabbet width, the length of the squeezed units were controlled in 2-10 mm. And the boards made with above units had good properties equivalent to normal particleboard and fiberboard with standard-satisfied TS, IB, MOR, and MOE values
