芳纶帘线在子午线轮胎中的应用

探讨新型原材料芳纶帘线在轿车及轻载车子午线轮胎中的应用问题，结合新型低滞后炭黑DZ-13在胎面胶中的应用试制了全纤维节能型子午线轮胎。全纤维节能型子午线轮胎完全能够达到国家标准，并且比普通子午线轮胎滚动阻力更低，更节油。     

制浆造纸工业用消泡剂的开发及应用进展

制浆造纸工业生产过程中不可避免会产生泡沫,泡沫控制不当会严重影响制浆造纸工艺条件的执行以及设备的正常运转,导致产品产量和质量降低,而控制泡沫最直接有效的措施是添加合适的消泡剂.该文介绍了制浆造纸工业生产中泡沫的产生和稳定机理,泡沫对制浆造纸工业生产过程和产品质量的影响,并针对制浆造纸生产中制浆、抄纸、涂布和脱墨等工段泡沫特性和消泡要求,综述了制浆造纸用消泡剂的发展历程、各工段消泡剂种类和性质,介绍了消泡剂的研制开发和实际应用成本及使用效果等,并对制浆造纸用消泡剂的发展进行了展望.     

Liquid spouting of pulp fibers in a conical vessel

Pulp fibers can be spouted in water in a conical vessel. The entities which are spouted are fiber flocs rather than individual fibers. Synthetic fibers, which do not flocculate, cannot be spouted. For comparison, rigid spherical particles were spouted with water in the same conical vessel. Liquid spouting of rigid particles was similar to gaseous spouting. For pulp spouting, the minimum spouting velocity is proportional to the mass of fibers in the bed and inversely proportional to the diameter of the inlet. For rigid particles, the minimum spouting velocity is proportional to the height of the bed and inversely proportional to the square of the diameter of the inlet. A model for the minimum spouting velocity was developed for pulp spouting.     

UV photo‐stabilization of tetrabutyl titanate for aramid fibers via sol–gel surface modification

Tetrabutyl titanate was used as sol–gel precursor of a nanosized TiO₂ coating to improve the photo‐stability of aramid fibers. The nanosized TiO₂ coating was characterized by XRD and XPS. The influence of the TiO₂ coating on photo‐stability of aramid fibers was investigated by an accelerated photo‐ageing method. The photo‐stability of aramid fiber showed obvious improvement after coating. After 156 h of UV exposure, the coated fibers showed less deterioration in mechanical properties with the retained tensile strength and elongation at break greater than 36 and 50% of the original values, respectively, whereas the uncoated fibers degraded completely and became powdery. SEM analysis showed no significant surface morphological change on the coated fiber after the exposure, while some latitudinal crack fractures appeared on the uncoated aramid fiber. The effect of the nanosized TiO₂ coating was also well demonstrated by examining the difference of distributions of C1s in XPS deconvolution analysis on the surface of uncoated/coated fibers with increasing UV exposure time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3113–3119, 2007     

芳纶纤维在轮胎工业中的应用

笔者主要介绍了芳纶纤维(包括长纤维和短纤维)的性能及其在轮胎工业的应用，同时简要叙述了芳纶纤维的分类和发展历史。     

CaCO3粒子及其增韧母料对聚丙烯材料力学性能的影响

采用扫描电镜、红外光谱和材料力学性能试验等方法研究了表面处理剂品种、CaCO3粒径及含量对均聚PP／CaCO3、共聚PP／CaCO3和PP／弹性体／CaCO3共混材料力学性能的影响。结果表明，采用平均粒径在1．0μm左右并经端噁唑啉聚醚、烷氧焦磷酸酯型钛酸酯等复合处理的CaCO3或其增韧母料增韧PP，可使均聚PP、共聚PP的缺口冲击强度提高至2．5～3倍，弯曲模量提高至1．2～1．4倍，可以在较少的弹性体用量条件下较大幅度地提高PP/弹性体共混材料的缺口冲击强度，并同时保持较高的弯曲模量和熔体流动性。红外光谱和扫描电镜分析表明，端噁唑啉聚醚等复合偶联助剂在CaCO3表面的作用及其弹性包覆层的形成是加强界面相的粘结、缓冲基体成型收缩应力、减少界面处微裂缝形成和提高材料缺口冲击强度的关键。     

纳米CaCO3对聚烯烃色母粒色彩性能的影响

用纳米CaCO3和普通活化CaCO3分别替代不同比例的颜料应用于聚烯烃色母粒中，利用测色仪测定色母粒制成的薄膜和样板制品的着色力和遮盖力，研究其对色母粒色彩性能的影响，并进行比较。结果表明，在不改变被着色制品色彩性能的前提下，纳米CaCO3可以替代部分颜料，且效果略优于普通活化CaCO3。色母粒中纳米CaCO3含量为10％（质量分数，下同）时，薄膜制品的光密度最大，遮盖力最高，分散效果最好。颜料的着色力在纳米CaCO3含量为20％时提高程度最大，而且体系的分散性也得到改善。     

Diffusion of lignin macromolecules within the fibre walls of kraft pulp. Part I: Determination of the diffusion coefficient under alkaline conditions

The intrinsic rate of diffusion of soluble lignin from fibre walls to bulk liquor has never been determined previously because of experimental difficulties; for example, the diffusion rate determined in a stirred cell is affected by the mechanical action of stirring. In our work, the intrinsic rate of diffusion of lignin macromolecules from the fibre walls of a softwood kraft pulp was determined under alkaline conditions using a displacement cell which eliminated external heat and mass transfer resistances and pulp fibre disturbances. The effects of such experimental conditions as pulp bed height and liquid flow rate were studied. The diffusion rate can be described by a diffusion model for a hollow cylinder with a very wide range of diffusion coefficients. The diffusion rate increased with increasing pH. Our results provide a new understanding of the lignin diffusion process in fibre walls, which is affected by the size of lignin molecules and the pores, and by the electrostatic interactions between intrafibre pore walls and lignin.     

Near Wall Studies of Pulp Suspension Flow Using LDA

A detailed study of the flow behaviour in the near wall region of pulp suspensions up to 4.7% have been performed using Laser Doppler Anemometry (LDA) in pipe flow. Axial mean velocity profiles show a distinct plug flow and an increase of the plug region as the flow rate decreases and fibre concentration increases. An attempt is made to relate the LDA data‐rate to fibre concentration, which indicates a dilution region at 1‐2 mm from the wall that is larger than the annulus region. The dilution region increases with increasing flow rate, decreasing concentration and when using longer pulp fibres.     

Spray Drying Performance of a Laboratory Spray Dryer for Tomato Powder Preparation

This work investigates the performance of a spray dryer for tomato powder preparation by spray drying of tomato pulp. Samples of tomato pulp with a 14% constant total solids concentration were used, and a pilot scale spray dryer (Buchi, B-191) with cocurrent operation and a two-fluid nozzle atomizer was employed for the spray drying process. Twenty-four different experiments were conducted keeping constant the feed rate, the feed temperature, and the atomizer pressure, and varying the compressed air flow rate, the flow rate of drying rate, and the air inlet temperature. In each experiment the air outlet temperature was recorded. Data for the residue remaining in the chamber and cyclone walls was gathered and two types of efficiencies were calculated as an indication of the spray dryer performance. Analysis of experimental data yielded correlations between residue accumulation and the variable operating conditions. The same operating parameters had a great influence on the air outlet temperature whereas temperature deviations were observed comparing measured air outlet temperatures with corresponding outlet adiabatic saturation temperatures.