基于UG前盖注塑模设计及模流分析

本文通过对前盖塑料件的结构特点进行了工艺性分析及注射模的模流分析,用三维CAD软件UG对前盖注塑模具结构进行了设计。详细阐述了塑件的注射模分型面、型腔布局、浇注系统、温度调节系统、抽芯机构和排气系统的设计过程及其模具的工作过程。同时还用MoldFlow Plastics Insight(MPI)软件对充模、流动、冷却等方面进行模拟分析。     

鼠标面盖双色注塑模具设计

根据鼠标面盖塑件的结构特点,对该制品的双色注塑模具进行了详细的结构设计。重点介绍了模具的设计过程、工作过程、设计经验和技巧。通过对浇注系统、侧向抽芯机构、冷却系统和脱模系统的分析研究,确定了合理的双色注塑模具结构。通过采用双模架、双浇注系统、双脱模系统和辅助型芯等复杂模具结构,达到了双色注射成型的特殊要求。     

笔记本电脑屏幕框热流道注射模具设计

通过对笔记本电脑屏幕框的结构及成型工艺分析,对该塑件的热流道注射模具进行了设计。重点围绕模具的分型面、浇注系统、侧抽芯机构、推出机构、排气及冷却系统等方面展开了设计分析,确定了模具合理的组成结构。通过对模具的热流道浇注系统、滑块侧向抽芯对分型面的调整及斜推杆内侧抽芯的改良性设计,进一步提高了塑件质量与生产效率,降低了制造成本,为同类结构特点的注射模设计提供了参考。     

右前门外拉手盖注射模具设计

分析右前门外拉手盖的结构工艺性,介绍该注射模具关键机构的技术要点及设计思路。根据产品结构设计出模具的浇注系统、成形零件、顶出机构、侧抽芯机构以及冷却系统,特别是采用二级滑块抽芯机构合理地解决斜孔成型与抽芯的工艺难题。结果表明,该模具结构紧凑,动作可靠,可为类似结构的注射模具提供借鉴。     

台灯底座下盖注塑模具设计

分析了台灯底座下盖塑料件的产品特点,确定了台灯底座下盖注射成型工艺,在此基础上,确定型腔数量及排列方式,设计了模具结构,优化了模具型芯、型腔、冷却系统等的设计,并重点介绍了主流道、衬套、推出机构等典型零部件的设计,其设计思路对相关塑料件的设计具有一定的借鉴意义。     

汽车仪表盘盖侧抽热流道注塑模设计

以汽车仪表盘壳盖为依据,分析了塑件结构及原料特点,设计了壳盖侧抽热流道注塑模,对该模具的结构方案、浇注系统、成型零件、侧抽芯机构、顶出机构及冷却系统进行了设计计算。结果表明,该模具结构设计合理,节约材料和能源。     

塑料压力盖模具设计与制造

本设计为塑料压力盖模具设计,介绍了压力盖注射模的结构及工作过程,着重介绍了一种新颖的采用斜导柱驱动方法进行侧向抽芯机构的结构设计,并阐述了该模具的工作过程,介绍了注射模设计中采用的强制脱模、滑动型延时顶出机构。本设计在保证加工质量的前提下。尽量做到在提高生产率的同时把生产成本降到最低。     

控制器盖注射模设计

通过控制器盖塑料件注射模具的设计,阐述了该模具组合式成型零件及侧向抽芯机构的设计方法。该模具总体结构设计合理,型腔、型芯和侧向抽芯均采用组合式结构,降低了模具的制造难度,从而降低了模具的制造成本,且缩短了生产周期。该模具的抽芯动作及脱模均平稳可靠,采用潜伏式浇口,保证了塑料件的外观质量,满足了技术要求。     

扣盖成型的注射模设计

本设计主要是针对扣盖的注射模具设计,通过对塑件进行工艺的分析及其结构分析。从产品结构工艺性,具体模具结构出发,对模具的浇注系统、模具成型部分的结构、顶出系统、注射机的选择及有关参数的校核都有详细的设计。通过模具设计表明该模具能达到扣盖的质量和加工工艺要求。     

扣盖成型的注射模设计

本设计主要是针对扣盖的注射模具设计,通过对塑件进行工艺的分析及其结构分析。从产品结构工艺性,具体模具结构出发,对模具的浇注系统、模具成型部分的结构、顶出系统、注射机的选择及有关参数的校核、都有详细的设计。通过模具设计表明该模具能达到扣盖的质量和加工工艺要求。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。