制造无胶纤维板过程中木纤维形态特征及化学特性——以酸性蒸气蒸煮热磨制造方法为例

Morphological Characteristics and Chemical Properties of Wood Fiber in the Binderless Fiberboard during the Manufacture Process with the Acidic Steam Steaming Hot Mill Method

以杨木木片、按常规中密度纤维板生产方法热磨得到的杨木纤维、经酸性蒸气蒸煮热磨得到的杨木纤维、酸性蒸气蒸煮热磨法制造的无胶纤维板为原料,用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶变换红外吸收光谱(FTIR),对酸性蒸气蒸煮热磨法制造无胶纤维板过程中不同阶段的木纤维的形态特征变化、结晶特性和化学组分进行表征分析,并进一步对不同阶段木纤维细胞壁各组分的化学变化进行测量分析。结果表明:热磨过程中木纤维表面光滑,酸化热磨纤维表面凸凹不平,增加了纤维间的啮合,有利于纤维板的成型,无胶纤维板中木纤维相互呈网状交联结构。整个处理过程并未改变木纤维的晶型结构,其晶型结构仍为天然纤维素Ⅰ型结构。FITR分析表明:杨木木片在酸性蒸气蒸煮热磨过程中,木纤维的木质素发生降解,各纤维间经羟基缔合形成了氢键,有利于纤维间自胶胶合成板。化学测试分析结构,进一步证实了木纤维在酸化热磨过程中木质素和游离糠醛质量分数增加,均有益于纤维间胶合。

The experiment was conducted to study the morphological characteristics and chemical properties of the binderless fi-berboard used wood fiber during the manufacture process by the acidic steam steaming hot mill method, with the poplar wooden chips, the fiber stemmed from the conventional method of medium density fiberboard, the poplar fiber with acidifi-cation and the binderless fiberboard making through acidic steam steaming hot mill method.By scanning electron microsco-py（SEM）, X-ray powder diffraction （XRD） and Fourier transform infrared spectroscopy （FTIR）, the experiment was conducted to characterize the morphological characteristics , crystallization properties and chemical composition of the wood fiber at the different stages in the course of the manufacture process of the binderless fiberboard by the acidic steam steam-ing hot mill method, and analyze the chemical changes of the cell walls of wood fibers at the different stages.In the process of hot mill, wood fiber surface is smooth and the poplar fiber with acidification surfaces is rough and uneven.The surface roughness increases the engagement between the fibers and is conducive to form the binderless fiberboard.The wood fibers are reticular crosslinked structure to each other in the binderless fiberboard.The whole process does not change the crystal structure of wood fiber and its crystal structure is still the natural cellulose Type I structure.By FTIR, the lignin degrada-tion occurs in the process of wood fiber hot mill acidification and formed hydrogen bonds between the fibers due to the hy-droxyl association.The hydrogen bonds are advantage for the fibers to self-adhesive glue into boards.In the process of wood fiber hot mill, acidification can promote the decomposition extend of cellulose, and increase the content of free furfu-ral with benefit for forming the binderless fiberboard.