Mechanical pulping

目标-短期目标是寻求提高机械纤维质量的创新方法，以便将其用于高性能等级或新等级的纸制品，而长期目标是将机械纤维提高到最高价值，以便提供新的或增强的效益并降低制造成本。研究计划和科学方法-1.剪切力和压缩力对纤维分离和表面原纤化的影响：可以对实验室的PFI磨机进行改造，以提供不同的剪压比。打磨间隙和纸浆浓度等其他条件也可以改变。纸浆特性，如自由度、抗张、破裂、撕裂、光散射、不透明度、保水值、纤维长度分布、细度、卷曲、卷曲、粗糙度、细胞壁厚度和柔韧性将被确定。还将进行扫描电子显微镜和X射线光电子能谱研究。2.TMP中长纤维的氧化：机械浆中长纤维的粘合能力较差，可以通过臭氧和4-乙酰胺-TEMP的氧化来修复，在纤维表面产生酸性基团，这对纤维间的粘合是重要的。3.TMP纤维的阳离子化：机械浆长纤维带负电荷的表面可以阳离子化，与短纤维和细小纤维以及与填料和助留剂产生更好的粘附性。纤维表面的阳离子化可以使用一种名为3-氯-2-羟丙基三甲基氯化铵(CHPTMAC)的阳离子试剂来完成，这种阳离子试剂通常用于阳离子淀粉。

Objectives - The short term objective is to search for innovative ways to enhance the quality of mechanical fibre so that it can be used in high performance grades or new grades of paper products, while the long term objective is to raise mechanical fibre to its highest value so that it can provide new or enhanced benefits and reduce manufacturing costs. Research Programs and Scientific Approaches - 1.  Influence of shear and compressive forces on fibre separation and surface fibrillation:  A laboratory PFI mill can be modified to provide varying shear-to-compression ratios. Other conditions such as refining gap and pulp consistency can also be varied. Pulp characteristics such as freeness, tensile, burst, tear, light scattering, opacity, water retention value, fibre length distribution, fines, curl, kink, coarseness, cell wall thickness and flexibility will be determined. SEM and XPS studies will also be conducted. 2.  Oxidation of long fibres from TMP: The poor bonding capacity of long fibres of mechanical pulp can be remedied by oxidation using ozone and 4-acetamido-TEMP, generating acidic groups on fibre surface which is important for inter-fibre bonding. 3.  Cationization of TMP fibres: The negatively charged surface of long fibres of mechanical pulp can be cationized to yield better adhesion with the short fibres and fines, and with filler and retention agents. Cationization of fibre surface can be done using a cationizing agent called 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTMAC), which is commonly used to cationize starch.