Birla Excel纤维赛络针织纱的生产

探讨Birla Excel纤维赛络针织纱的纺纱工艺.根据纤维断裂强度较高、伸长率较大且卷曲自然持久等特性,制定了合理的生产工艺,开清棉工序主要采取“多松少打、减少落棉、大隔距”的工艺原则,梳棉工序采用“轻定量、慢车速、隔距适中”的工艺原则,细纱工序采取优化工艺配置并选用J463型胶辊、重加压等措施提高成纱质量,同时采用低温蒸纱等措施解决成纱捻接强力不高的问题.通过实施一系列措施,生产的Birla Excel纤维赛络针织纱各项质量指标均达到了使用要求.     

THE MAGNIFICATION FACTOR IN SPINNING DROP INTERFACIAL TENSIOMETRY

The accuracy with which the interfacial tension between two immiscible fluid phases can be determined by the spinning drop method is limited by the accuracy with which the spinning drop diameter can be found. Thus, it is important to know the factor by which the cylindrical sample tube and its content magnifies the on-axis drop or bubble. Here, we analyze the image formation and magnification factor of the spinning drop by a non-paraxial ray tracing method of geometric optics. Our analysis shows that when the drop and the walls of the lube are concentric, the magnification factor is exactly the refractive index of the denser fluid surrounding the drop and is independent of the refractive index and wall thickness of the sample tube. Our analysis also reveals that the image, a virtual one, is formed concentric with the drop.     

金属的旋压技术

介绍了旋压技术的发展,特点及应用。     

浅谈美棉品质与成纱质量的关系

通过试验分析了美棉的物理性能,美棉纤维成熟度好,纺纱过程中杂质易排除,因而成纱疵点明显减少;但美棉加工质量差异大,含杂多,纤维长度较短.美棉质量大致可分为较好、一般、较差,在具体使用时,纺细号纱可少用,纺中号纱可适当多用,纺粗号纱可集中使用.     

论粗纱机"恒离心力纺纱"

给出了粗纱机纺纱离心力的表达式，提出了“离心张力”的概念，导出了离心张力的变化规律。认为“恒离心力纺纱”的提法不够严谨，所列离心力表达式有误；按“恒离心力”的要求调控锭速是不合理和不可行的，较合理的方法是采用“限离心力”的方式调控锭速。降低锭速也不是减小离心张力的惟一方法。     

HS401型纺丝机的技术改造

针对纺丝机存在的缺陷,分析了原因,决定利用检修机会,从原液输出、喷头成形、提高纤维强度方面进行技术改造,从而使腈纶纤维的物理性能和质量指标提高很多,设备的平稳率得到了显著提高,检修次数明显减少,取得了较好地经济效益。     

旋压机控制原理的分析与应用

分析了旋压瞬时主轴与成形辊及板材接触点的速度变化状态。首次成功地应用了力反馈控制原理 ,设计出恒功率自适应同步控制系统 ,从而满足了旋压过程中啮合点任意瞬时、任意位置的同步要求。     

Thin film flow over spinning discs: The effect of surface topography and flow rate modulation

We examine the effect of disc topography and time modulation of the liquid flow rate at the inlet on the dynamics of a thin film flowing over a spinning disc. We use a combination of boundary-layer theory and the Kármán-Polhausen approximation to derive coupled equations for the film thickness, and radial and azimuthal flow rates. Substrate patterning is taken into account in the limit of small-amplitude topography. Our numerical results indicate that the combined effects of flow rate modulation at the inlet and disc patterning can lead to a significant increase in interfacial waviness, which greatly exceeds that associated with the constant flow rate, smooth disc case.     

Synthesis of submicron barium carbonate using a high-gravity technique

The purpose of this study was to build a platform for producing fine particles by applying a high-gravity (higee) technique to achieve reactive precipitation. Barium carbonate was chosen as a model compound and was produced in a spinning disk reactor (SDR), which is one type of higee equipment, via a carbonation route and a once-through mode. For size measurement, a suitable dispersion method was developed to obtain reproducible particle size data, using a laser-light analyzer. Several factors that affected the particle size of barium carbonate, including the CO₂ flow rate, the feed rate of Ba(OH)₂ slurry, the rotation speed, and the solid-content of feed slurry, were investigated. A high rotating speed and low feeding rate of slurry yielded small particles. The optimum solid-content of feeding slurry for obtaining small particles was also determined. However, the effect of the CO₂ flow rate on the particle size of the product was not significant.     

A fresh look at the free flight dynamics of a spinning projectile

In the first part of the paper, several equations of motion by different groups of workers are critically examined. Exact equations of motion are then developed. This form is then quasi-linearised into a ballistic formulation. The geometrical motion of a spinning projectile, in the presence of a cubic restoring moment is analysed in the cross-flow plane. It is observed that the trajectories assume a cuspidal form at the lower and upper range of the travel, when the angular momentum parameter coincides with these points. In general, both steady and unsteady precessional motions are presented.