力劲集团主打薄壁件快速注射成型机

<正>力劲集团推介最新技术成果、产品解决方案。作为中国最大注塑机制造商之一,力劲科技集团有限公司推出两款融入多项最新科技的注塑机产品为PT160F高速精密直压注塑机和PT130B快速注塑机。力劲全新的注塑成型解决方案中,PT160F是一款3C专用机,主要面向光盘、手机配件、电脑配     

气体辅助注塑在彩电外壳中的应用

研究彩电外壳注塑和气体辅助注塑充模过程的计算机模拟和实际生产。应用动态应力流变仪测试材料流变性质,得到模拟所需n、B、τ、β、T_b等5个参数。考察熔体注射温度、注射时间、入口位置、材料性质对充模过程的影响,得到优化充模结果;还考察了气体辅助注塑过程熔体预注射量、气体注射压力对充模过程的影响。结果表明,气体辅助注塑成型新工艺采用三浇口,熔体适宜预注入量为95％,注射温度230℃,注射时间5s,用幂律指数n较小的聚合物。     

Natural Convection of Nanofluid in Cylindrical Enclosure Filled with Porous Media

A numerical study has been carried out to investigate the effect of aspect ratio on heat transfer by natural convection of nanofluid taking Cu nano particles and the water as based fluid. The flow is laminar, steady state, axisymmetric two-dimensional in a vertical cylindrical channel filled with porous media. Heat is generated uniformly along the center of the channel with its vertical surface remain with cooled constant wall temperature and insulated horizontal top and bottom surfaces. The governing equations which used are continuity, momentum and energy equations using Darcy law and Boussinesq＇s approximation which are transformed to dimensionless equations. The finite difference approach is used to obtain all the computational results using the MATLAB-7 program. The parameters affected on the system are Rayleigh number ranging within （10≤ Ra ≤ 103）, aspect ratio （1 ≤ As 〈 5） and the volume fraction （0 ≤0 〈 0.2）. The results obtained are presented graphically in the form of streamline and isotherm contour plots and the results show that as ~ increase from 0.01 to 0.2 the value of the mean Nusselt number increase 50.4% for Ra = 1,000.     

电话机(1929年)

英国邮政总局 ( GPO) 1 62电话分局于 1 92 9年开始营运 ,这种“手持通话设备”一直没有太大的改变 ,其“2 0 0系列”标准样式直至 2 0世纪六十年代才由现代热塑性塑料为基体的话机所取代。　　 1 62电话分局使用了世界上首部全塑外壳电话机 ,整套电话机包括机座和话筒重量仅为 1 .9kg,而GPO162 TELEPHONE(192 9)　　 The General Post Office( GPO) 1 62 was intro-duced in the UK in 1 92 9.It was also known as the'hand combination set'.With only minor variations,the'2 0 0 series'to which it belonged was to remain…     

ELG外壳连续拉深模设计

通过对某微波炉ELG外壳的冲压工艺分析及计算,提出了针对该制件采用双侧载体及内、外圈3个方向搭边的排样方案.介绍了该制件的整体模具结构及主要部位的局部机构设计,并对整形工序中的凸模微调装置机构及调整动作进行详细说明,每调整1次可在10 min以内完成,大大节省了模具调试时间.在排样设计中,充分利用带料毛坯外圈的搭边形状特点,将其中1个方向的搭边设置在两个制件之间的对应位置,可以减短步距而不影响带料刚度,从而有效提高材料利用率.为确保带料在连续拉深后送料畅通,该模具在带料两侧设置了浮动导料销装置.冲压实验结果表明,所设计的模具结构紧凑,冲压制件质量良好,可以满足大批量生产需求.     

Optical and structural properties of highly porous shell structured Fe doped TiO2 thin films

TiO2thin films with 0.2 wt%, 0.4 wt%, 0.6wt%, and 0.8 wt% Fe were prepared on glass and silicon substrates using sol–gel spin coating technique. The optical cut-off points are increasingly red-shifted and the absorption edge is shifted over the higher wavelength region with Fe content increasing. As Fe content increases, the optical band gap decreases from 3.03 to 2.48 eV whereas the tail width increases from 0.26 to 1.43 eV. The X-ray diffraction（XRD） patterns for doped films at 0.2 wt% and0.8 wt% Fe reveal no characteristic peaks, indicating that the film is amorphous whereas undoped TiO2exhibits（101） orientation with anatase phase. Thin films of higher Fe content exhibit a homogeneous, uniform, and nanostructured highly porous shell morphology.     

鼠标外壳的注塑模设计及数控加工

本文主要使用了Pro/E软件的模具设计模块对鼠标外壳零件进行了模具设计,并在此基础上利用它的NC加工模块对凸模进行了数控编程。     

一种加装补偿散热装置的大容量电力电容器设计

目前,容量小的高电压电力电容器,由于发热量比较小,依靠本身外壳表面散热,足以使电容器温升控制在允许的范围内;同时依靠外壳的膨胀和缩小足以补偿因温度升高和降低变化引起外壳内体积增大和缩小.对于大容量的电容器,由于发热量大,单靠外壳的表面积散热不足以把电容器的温升控制在允许的范围内,需加装散热器;同时由于容量大,体积大,外...     

IT、AV类电子产品阻燃试验的选择

在实践的基础上,本文主要根据GB 8898-2001<音频、视频及类似电子设备安全要求>以及GB 4943-2001<信息技术设备的安全>中的要求,结合自身在工作中的一些经验总结,来简单的探讨一下IT、AV类电子产品的阻燃材料试验的选择.