影响球头螺母力学强度因素研究

球头螺母是用聚酰胺66(PA66)制作的,聚酰胺分子中有酰胺基,吸湿性较大。球头螺母在用户装配时,常出现断裂纹和变软,拉脱力波动较大。为解决其拉脱力问题,本文对影响球头螺母拉脱力因素进行分析,其影响有产品结构、注塑工艺、后处理和储存等因素,并对产品结构、注塑工艺、后处理和储存作出了相应的调整和实践。经研究实践验证,解决了球头螺母裂纹和变软问题,稳定了拉脱力,保证了机械强度,产品能得到用户的认同。     

球头螺母成型工艺的改进及优化

用聚酰胺66(PA66)制作了球头螺母为解决产品装配时出现的断裂纹和变软问题,对球头螺母注塑工艺提出一些改进要点,对材料干燥、色母料、模具、调湿、检测作出了相应调整.工艺改进及优化后,解决了产品裂纹和变软问题,稳定了产品质量,得到了用户的认同.     

有机玻璃色母料的研制

本文较详细地介绍了有机玻璃色母料的研究、发展和应用情况。     

新型专用色母料对塑料管材性能的影响及应用

PP-B、PP-R、PEX、PE等管材专用原色料采用新型专用色母料着色后具有优良的色泽、分散性并保持管材专用原色料的物理力学性能、卫生性能以及管材的静液压性能指标。其主要性能接近或达到进口带色料的水平。技术经济分析的结果表明新型专用色母料技术有着很好的推广应用前景。     

医疗专用色母料

总部在瑞士Muttenz的Clariant(克莱恩)母料公司新推出专用于聚醚嵌段酰胺(polyether block amide,PEBA)和尼龙12的色母料。作为该公司Renol-med色母料系列产品的新上市商品,PEBA和尼龙12一般用于医疗有关的领域。新母料中的颜料和载体树脂都已通过美国药典(USP)Ⅵ级标准和试验认证。目前在美国缅因州Lewison的Clariant公司的一条专门生产医疗级色母料的挤出生产线,生产这种新母料,有不透明、     

色母料载体树脂选用的探讨

使用色母料碰到最大的困难也许是如何把它适当地添加到材料中。本文中关注两个主要因素,分别是用于生产色母的载体树脂及其分子量,而它们往往是不能由购买色母料的公司所能决定的。     

色母料和功能色母料的介绍

色母料是以着色剂、载体树脂、分散剂、偶联剂、表面活性剂、增塑剂制得的高浓度有色粒料;功能色母料除上述原料外,根据功能的要求须添加光稳定剂、抗静电剂、阻燃剂、发泡剂等助剂。     

硅橡胶色母料

据“Rubber World,2008,239（3）：58”报道,NuSil技术公司已着手对用于医疗保健、航空航天、电子和光学领域的硅橡胶材料——硅橡胶色母料进行敏感性、遗传毒性和热源试验,以提高其产品的生物兼容性。用于医疗保健领域的色母料需要有相应的规格,以便与用于弹性体的色母料的规格具有可比性。     

PVC专用高效色母料

英国Wrexham的Silvergate Polymers公司是British Vita公司的色母料业务分部．现推出一种专用于聚氯乙烯（PVC）的新色母料产品。该公司预计新产品将会在市场上引起极大反响和兴趣,为满足未来预期的需求,已安装新的双螺杆挤出生产线,提高新产品产量。     

色母料专用浸润分散剂

据“European Plastics News”，2004，31（10）：30报道，德国Byk-Chemie公司新推出3个热塑性塑料色母料制备专用浸润（wetting）分散剂Disper-plast牌号。     

不同试样对聚合釜封头拉伸性能检测结果的影响

介绍了影响聚合釜封头试样拉伸性能的因素:取样部位、取样方向和取样数量及试样的横截面形状。检测结果表明:圆形横截面试样比矩形横截面试样的断后伸长率高。     

Effect of ball milling treatment on the microstructures and properties of Cr2AlC powders and hot pressed bulk ceramics

Ball milling was used on synthesized Cr₂AlC powders, and dense Cr₂AlC bulk ceramics with almost pure phase were fabricated by hot pressing these ball milled Cr₂AlC powders at 1300 °C for 2 h under 30 MPa. The phase compositions and the microstructures of powders and bulk ceramics were characterized. The mechanical properties and dislocation analysis of bulk ceramics were also investigated. Our results indicated that the grain size of powders became uniform and smaller after ball milling, which was also inherited in the bulk ceramics. Moreover, the mechanical properties of hot pressed Cr₂AlC ceramics, including flexural strength, fracture toughness, and Vickers hardness, significantly increased by using ball milled powders treated at speed 200 rpm. The organization of hexagonal dislocation networks during hot pressing and reduction of grain size both had a positive effect on improving mechanical properties.     

Microstructural and diametral tensile strength evaluation of the zirconia-mullite composite

The purpose of the current research was to investigate the effect of duration of the mechanical activation process of starting materials on Vickers micro-hardness and diametral tensile strength of zirconia-mullite composites. Zirconia-mullite composites with 1:1?M ratio were fabricated by sintering of the mechanically activated kaolinite, gibbsite, and zircon powder mixture as inexpensive and convenient starting materials. Results of dynamic light scattering analysis showed that the mean particle size of the starting powders was reduced from 2.5?µm to 80?nm after 72?h of the mechanical activation process. X-ray diffraction analysis showed that zirconia and mullite were crystallized after 2?h thermal treatment at 1550?°C. Based on the semi-quantification results of X-ray diffraction patterns, increasing the duration of the milling process from 6 to 72?h had a positive effect on improving the amount of tetragonal zirconia in the final matrix. Scanning electron microscopy results revealed a fine and homogeneous distribution of zirconia particles in the mullite matrix after 72?h of the mechanical activation process. Increasing the duration of milling process from 6?h to 72?h had a remarkable effect in increasing the diametral tensile strength values from 30 to 220?MPa. Vickers micro-hardness values were also enhanced considerably from 7.30 to 11.12?GPa by increasing the milling time.     

球磨参数对球磨法制备纳米WO3粉的影响分析

本文采用球磨法制备纳米三氧化钨陶瓷粉末,系统研究了球磨参数对粉末粒度的影响。结果表明,机械球磨法可以制取纯度较高的三氧化钨细粉;球磨时间和球料比以颗粒尺寸趋于稳定的范围为佳,盲目延长时间、增大球料比起不到细化作用,相反会增加杂质的引入。     

The influence of RPCA on the strength and fracture toughness of HPC

The paper presents the study on the relationship among mechanical properties, including compressive strength, splitting tensile strength, fracture toughness, and rupture probability of coarse aggregate (RPCA) of high-performance concrete (HPC) with varied aggregate sizes. For the maximum aggregate size of 16 mm, the compressive and splitting tensile strength and the corresponding RPCA reached the maximum values. As the mechanical properties linearly increased with the increasing RPCA, RPCA has been confirmed as a useful parameter to express the mechanical behavior of HPC. Preliminary analysis also showed good relationships between the mechanical properties and RPCA.     

汽车用厌氧螺纹锁固胶扭矩的影响因素研究

介绍了汽车用厌氧型螺纹锁固胶的固化机理,并以天山公司产品为例介绍了厌氧型螺纹锁固胶扭矩的影响因素,包括固化温度、固化时间、螺栓表面状态、螺栓类型、间隙等等,并与国外同类产品做了对比试验,     

The influence of the alite polymorphism on the strength of the Portland cement

The influence of the alite polymorphism on the strength of cement was monitored in a set of laboratory-prepared clinkers with equal quantitative phase composition and different ratio of modifications. The alite polymorphism in clinkers was influenced by the change of the MgO and SO₃ side oxides in clinker, raw meal reactivity change, raw meal preheating, burning temperature or by the adding of crystallisation nuclei. The differences in the hydraulic properties of the M₁ and M₃ modifications were determined. In the case of all the hydration periods monitored, the strength of cements with the M₁ modification was 10% higher than the strength of cements with the M₃ modification.     

Use of the attainable region analysis to optimize particle breakage in a ball mill

Particle size reduction is one of the most widely encountered, yet least energy efficient, processes. Therefore, potentially significant energy and cost savings exist with even the slightest increase in milling efficiency. Often one would like to mill particles to a certain size, and no smaller, while minimizing energy use and milling time. We use the attainable region (AR) analysis to optimize the comminution of silica sand particles in a bench top laboratory ball mill. When the mill is loaded with a large number of grinding media (J=volume of media/mill volume=10.7%), the breakage profiles are indistinguishable over all rotation rates investigated. However, operation at lower grinding media fill level (J=1.5%) reveals separation between the grinding profiles for different rotation rates, suggesting more efficient breakage occurs at a lower grinding media fill level for a given rotation rate. Our results show that operation at multiple speeds, fast at first and then slower (φ_c=0.03), takes advantage of the initially overlapping grinding profiles and produces a similar particle size distribution with a decreased amount of processing time—less than half the time required for the single rotation rate milling. A natural extension of this idea is continuous milling, where the first mill can operate at a higher energy input for a shorter amount of time and the second mill can operate at a lower energy input for a longer amount of time.