Development of a process raman probe of wood pulp as a continuous gauge of the physical and mechanical properties of end-use product: spectroscopy and chemometrics

加拿大北方漂白软木硫酸盐浆（NBSK）市场纸浆代表了纤维强度、长度、细度和均匀性的全球基准。为了保持在世界市场上的领先地位，加拿大纸浆工业必须不断开发和部署工艺技术，加强纸浆成分的质量控制，特别是参考那些决定工艺参数和关键产品性能的内在纤维特性，如拉伸强度，柔软度和吸收性。例如，纤维素结晶度和化学成分（如木质素、半羟甲基纤维素和己烯糖醛酸（HexA））的分布决定纸浆的消化率和漂白性，而在制浆过程中引起的纤维变形程度影响纤维在片材形成期间如何在网络中提供强度和柔软度。这些和其他参数已被证明是制造效率、能量利用、环境性能和产品价值的重要决定因素，然而，除了木质素之外，没有一个参数可以容易地及时测量以用于过程控制。目前的建议要求开发一种新的拉曼系统，和系统的化学计量方法，将允许快速的光谱数据采集和明确的光谱化学分析湿纸浆在苛刻的制造条件下。该仪器系统将联合收割机结合一种新的背散射拉曼探针与复杂的化学计量学数据处理策略，采用小波变换和模板引导的遗传算法（TOGA）特征选择与多元分类，以提取最大的分析信息，从原始拉曼光谱。一项将光谱化学观察结果与纤维参数（如卷曲、粗糙度、面积、周长和CSF）和最终用途纸张性质（包括破裂、拉伸、撕裂、平滑度、压缩、刚度、TEA和拉伸指数）的常规表征相关联的研究计划，将产生一种全面的拉曼仪，用于纸浆质量的瞬时测定和纸张外观、强度、柔软性和吸收性。

Canadian northern bleached softwood kraft (NBSK) market pulps represent the worldwide benchmark for fibre strength, length, fineness, and uniformity. To maintain this premier position in the world marketplace, the Canadian pulp industry must continuously develop and deploy process technologies that sharpen the quality control of pulp composition, particularly with reference to those intrinsic fibre characteristics that govern process parameters and key product properties, such as tensile strength, softness and absorbency. For example, the degree of cellulose crystallinity and distribution of chemical constituents, such as lignin, hemicullose, and hexenuronic acid (HexA), determine pulp digestibility and bleachability, while the degree of fibre deformation incurred during pulping process affects how the fibre delivers strength and softness in a network during sheet formation. These and other parameters have been shown to be important determinants of manufacturing efficiency, energy utilization, environmental performance and product value, however, aside from lignin, none can be easily measured in a timely manner for process control. The present proposal calls for the development of a novel Raman system, and systematic chemometric approach that will allow for rapid spectral data acquisition and definitive spectrochemical analysis of wet pulp under harsh manufacturing conditions. The instrument system will combine a novel backscattering Raman probe with a sophisticated chemometrics data-processing strategy, employing wavelet transform and template-guided genetic-algorithm (TOGA) feature selection with multivariate classification to extract maximum analytical information from raw Raman spectra. A program of research correlating spectrochemical observations with conventional characterization of fibre parameters, such as, curl, coarseness, area, perimeter and CSF, and end-use sheet properties, including burst, stretch, tear, smoothness, compression, stiffness, TEA and tensile indices, will give rise to a comprehensive Raman gauge for the instantaneous determination of pulp quality and the online prediction of paper appearance, strength, softness and absorbency.