精梳机钛合金钳板制造技术研究

从分析精梳机钳板工作原理着手,为提高工作钳次、减轻钳板重量进行了钛合金钳板制造工艺的开发试验,成功制造出钛合金钳板,为提升精梳机产品性能奠定了工艺基础。     

棉纺精梳机钳板的变形及其应力分析

为研究棉纺精梳机下钳板工作状态时的变形与应力,对钳板钳持过程的动力学进行分析,建立了弹簧压力、钳板钳持力矩、钳板有效压力、下钳板变形及应力的数学模型;利用Ansys有限元分析软件对分别采用铬合金、铝合金及钛合金时下钳板的应力及变形进行仿真及分析。结果表明:在钳板钳口钳持状态下,3种不同合金材料的下钳板的实际最大应力远小于其许用应力;在工作状态时,3种不同合金材料下钳板的最大变形分别为钛合金0.008 mm, 铝合金0.010 3 mm, 铬合金0.019 3 mm,即采用钛合金下钳板时下钳板变形最小,有利于改善上下钳板握持状态,改善梳理质量及减少可纺纤维损失。     

经编机钳针保全技术研究

研究经编机保全过程中的钳针技术,介绍钳针的基本概念及技术要求,详细阐述针钳的使用方法、钳针的操作步骤以及8种实施方法,包括捋法、掰法、挑法、推法、拉法、镊法、敲法、顶法。进一步说明钳针的分类及注意事项,归纳总结出不同针件的钳针技艺,包括钳织针、钳针芯、钳沉降片、钳导纱针、钳分纱针技术,为经编机保全工作提供技术支持。     

燃气器具铜合金阀体液态挤压新工艺及模具设计

采用液态挤压代替普通热模锻生产燃气器具铜合金阀体，不驻提高了材料利用率，而且减少了锻造设备的投资。本文介绍了阀体材料、锻件设计、液态挤压模具结构及设计参数，分析了液态挤压的工艺参数及选择依据、产品的技术经济。     

棉纺精梳机钳板摆轴的动力学分析

为分析棉纺精梳机钳板摆轴驱动力矩的变化规律,探讨了锡林梳理力、分离牵伸力、钳板机构惯性力、钳板摆轴惯性力及其与钳板摆轴驱动力矩关系。建立了钳板摆轴阻力矩及驱动力矩的数学模型,运用ADAMS软件对一个工作周期内钳板摆轴的阻力矩及驱动力矩的变化规律进行仿真模拟。结果表明:钳板摆轴的驱动力矩主要取决于钳板机构的惯性力对钳板摆轴的矩;随着精梳机的速度提高,钳板摆轴驱动力矩变化曲线的峰值及谷值迅速增大,钳板机构的惯性力对钳板摆轴驱动力矩影响增大;当精梳机的速度由300提高至500钳次/min时,驱动力矩曲线的峰值增大211%,钳板机构惯性力矩峰值与钳板摆轴驱动力矩峰值比值由63%增至74.1%。     

鲤鱼钳镶配平面推削

鲤鱼钳用途甚广,它能剪切扭转夹持及扳动拔起等功能,是机械装修和家庭日常必备工具之一.模锻压坯件要经加工镶配平面及头部内侧面、粗细齿工作面与冲切单双孔型.国内目前都用铣削或粗磨镶配平面,生产效益低、成本高、光精度都差,尤其是铣削的镶配平面,厚薄公差大,两片钳体装配不能互换、头面错位大,要对号入座、给加工特别是电镀造成极大的困难.合格率低、成本高.近年来国内外已有厂家用推削镶配平面代替铣削工艺,获得了良好的技术经济效益,且能单片钳体互换生产装配.     

片梭织机梭钳的研制

本分析了瑞士苏尔泽鲁蒂片梭织机梭钳的一些特性和目前国内制作的梭钳的失效原因，提出了用５０ＣｒＶＡ钢制作梭钳，并且通过合适的多级预变形和热处理，使梭钳的磨损和疲劳寿命大大提高，达到１２００×１０＾４次以上。     

A201系列精梳机钳唇结构对梳理效果的影响

本文计算了Ａ２０１系列精梳机钳板钳唇的死隙长度、棉丛梳理长度和重复梳理次数；得出在钳唇的死隙长度短１．４ｍｍ时，棉丛的梳理长度和重复梳理次数增加１２．３％－１２．６％。试验表明：钳板钳唇结构改后和改前相比，棉结杂质总数减少１２．５－１４．８％，棉网清晰度有所改善。     

E7／5型精梳机钳板传动机构分析

运用计算机对Ｅ７／５型精梳机的钳板机构进行了运动分析，得出了钳板摆轴及钳板的位移、速度及加速度规律。分析讨论了曲柄半径ｒ的大小与机械、工艺性能的关系，得出适当缩短曲柄半径ｒ、可减小钳板运动时的最大加速度和冲击力，并有利于提高棉丛的分离接合质量。     

精梳机一种新型钳板机构的方案设计

介绍了一种和传统精梳机相区别的精梳机钳板机构的新方案设计，该钳板摆轴传动机构采用具有停歇功能的共轭凸轮机构。采用新的钳板摆动机构使给棉罗拉固接在机架上，不随下钳板移动，减少了下钳板组件的质量；锡林位置下移，下钳板由原来的前后移动变为绕定点摆动．从而使给棉棉花须丛的搭接由原来的被动搭接变为主动搭接，有利于棉花须丛的搭接。     

Application of an In‐line Viscometer to Determine the Shear Stress of Plasticised Wheat Starch

An in‐line viscometer was designed and constructed to enable determination of the shear stress of plasticised wheat starch during extrusion cooking. The viscometer was installed between the end of the barrel section and the extruder die plate so that the shear stress could be determined for the plasticised material, irrespective of the geometrical shape into which it was subsequently moulded by the extruder die. The extrusion conditions were described in terms of the process parameters, i. e. water content, barrel temperature, screw speed and screw configuration; and of the system parameters, which were the specific mechanical energy input (SME), product temperature (PT) and mean residence time (MRT). The parameters were measured and the results evaluated using statistical methods. Regression equations were used to describe functional relationships between the shear stress and the extrusion conditions on the one hand, and between the shear stress and the product characteristics of the extrudates on the other. The shear stress of plasticised wheat starch determined in‐line can be used to predict the morphological structure (volumetric expansion) and the functional properties (cold paste viscosity and cold water solubility) of extruded, directly expanded starch with a high degree of accuracy. The measurement technique used and the results of the extrusion tests undertaken for this project will therefore enable the shear stress of plasticised material in an extruder to be used as the principle parameter for controlling extruders on‐line.     

高水分组织蛋白挤压工艺参数对系统参数及其物理特性的影响

以不同物料配比、水分含量和挤压温度条件下生产的高水分植物组织化蛋白产品为对象,研究挤压工艺参数对挤压输出的系统参数、产品质构特性和颜色特性的影响。结果表明,物料配比和物料含水量对模头压力、扭矩和单位机械能耗影响显著,分离蛋白含量与这3个参数呈正相关,而与物料水分含量呈负相关;在产品质构方面,物料的配比、含水量对质构参数有显著影响;在产品颜色方面,物料配比和含水量对产品亮度有显著影响,物料配比中的分离蛋白含量越高,亮度越低,而含水量越高,亮度越高。说明通过改变物料的配比及其含水量可以得到不同物理特性的蛋白产品,丰富产品种类,为高水分组织化蛋白产品的生产应用提供一定的理论依据。     

Extrusion behaviour of grits from flint and sweet corn

Studies were conducted to investigate the effect of feed moisture, extrusion temperature and screw speed on the extrusion behaviour and product characteristics of flint and sweet corn grits. The extruder die pressure and extrudate properties, such as expansion and water solubility index (WSI), were analyzed. Second order polynomials were computed to describe the extruder response and product properties of grits from both corn types as a function of feed moisture, extrusion temperature and screw speed. Among feed moisture, extrusion temperature and screw speed, feed moisture showed the most pronounced effect on die pressure, expansion and WSI. Die pressure of the extruder was significantly greater for sweet corn than flint corn grits. The grits from both the corn types differ significantly with respect to extrusion behaviour and product characteristics under similar extrusion conditions. The particle size distribution revealed that flint corn grits had more fine and opaque particles and resulted in extrudates with lower WSI and expansion than those from sweet corn grits which had fewer fine particles.     

高水分挤压组织化植物蛋白纤维结构形成机制研究进展

高水分挤压组织化技术是目前生产具有类似动物肉的纤维结构和口感的组织化植物蛋白的主要加工技术。旨在为未来新型植物性肉类类似物的加工和产品设计提供理论参考,从原辅料(植物蛋白、添加剂)、挤压系统参数(水添加量、挤压温度、螺杆转速和喂料速度)、冷却模头三个方面阐述对植物蛋白高水分挤压过程中纤维结构形成的影响机制。蛋白质分子间相互作用力是组织化植物蛋白纤维结构形成的关键,而不同的植物蛋白原料其组织化结构所依赖的蛋白质分子间作用力不同。添加剂可以改变蛋白质等分子内或分子间的作用方式和程度,从而直接影响组织化植物蛋白成品纤维结构的形成。挤压参数主要通过影响蛋白质结构来影响产品质构特性。冷却模头有利于各向异性纤维结构的形成。     

Use of a microwave-attenuation sensor for moisture measurement inside an extrusion cooker

A microwave strip line sensor has been inserted in the barrel of a pilot scale extrusion cooker immediately before the die. Experiments with maize grits have shown that the microwave attenuation is sensitive to the moisture content of the feed. Preliminary experiments with finer particulate feedstock indicate that the microwave attenuation also depends on the distribution of water within the viscous material at this point. A microwave sensor is shown to have potential for probing the material within an extrusion cooker for use in controlling product properties.     

An experimental study of twin-screw extrusion-cooking of maize grits

The use of a twin-screw extrusion-cooker to process maize grits is described. The expansion, bulk density, colour and aqueous dispersion rheology have been related to the extrusion cooking variables: screw speed, feed rate, moisture content and barrel zone temperature. A pseudo-viscosity quantity has been defined to describe the extrudate viscosity at the die which was also related to the extrusion-cooking variables. The pressure and temperature profiles in the extruder were recorded together with the mechanical and thermal energy consumption as a function of the extrusion-cooking variables. These experiments with a highly instrumented cooking-extruder indicate the condition of the material in the barrel prior to formation of the product.     

双螺杆挤压机操作参数变化对谷物产品特性的影响

对食品双螺杆挤压机的操作参数与挤出过程及谷物产品特性之间的关系作了试验研究。通过改变螺杆转速、进料速率这两个变化因素,研究模头压力、模头处物料温度、主机电流、产品膨化度、产品水溶性指数、产品吸水性指数等指标的变化规律,建立有关数学模型并进行分析。     

DS32-Ⅱ型多功能挤压膨化实验机的调试报告

对螺杆直径为32mm的小双螺杆多功能挤压膨化实验机加工性能进行了测试，结果表明，该机400mm机筒能用圆形模头挤压加工全膨化产品，600mm机筒能用单方孔管和薄片状模头加工半膨化产品，并且终产品膨化效果满足实验要求，该机需要改进的地方，一是还要多开发几个适用于全膨化和膨化加工的模头，二是要提高设备的加工稳定性。     

Effects of moisture,temperature and level of pea grits on extrusion behaviour and product characteristics of rice

A study was conducted to investigate the effect of feed moisture (18–24%), extrusion temperature (130–170 °C) and level of pea grits (0–30%) on the extrusion behaviour and extrudate properties of rice grits. The extruder die pressure, specific energy consumption, expansion ratio, density, water absorption index, and water solubility index were studied. Second-order polynomials were compared for extruder parameters and product characteristics as a function of feed moisture, extrusion temperature and pea grit level.     

挤压膨化技术在乙醇生产中的应用

采用挤压膨化技术代替传统乙醇发酵生产中的蒸煮液化阶段,对挤压膨化工艺参数进行了系统探讨。通过L16(44)正交实验确定了其适宜工艺参数:挤压机模孔直径11 mm,挤出物料温度170℃,物料含水量24%,挤压机螺杆转速200 r/min。在该工艺条件下,其乙醇体积分数提高了0.32%,原料出酒率比传统乙醇发酵生产工艺提高了1.06%,发酵时间缩短8 h。