<Emphasis Type="Italic">Rapid Moulding Using Epoxy Tooling Resin</Emphasis>

Rapid prototyping (RP) is fast becoming a standard tool in today’s product design and manufacturing environment. Significant benefits in terms of lead time and cost savings have been reported with the use of RP technology. However, these benefits can be derived only during the design and planning stages of a new product where RP parts are produced in small quantities for design evaluation, form fitting, and marketing analysis. The high cost of raw material stock used in current RP systems makes them economically unsuitable even for small-batch production during the product evaluation and manufacturing stages. Further to this, the difference between the mechanical and physical properties of RP and traditional manufacturing materials limits the functionality of RP end products. Rapid tooling (RT) technology has opened up new cost-effective solutions for small-batch production. In this paper, a technique using a rapid soft-tooling approach, namely, aluminium filled epoxy resin tooling for injection mould preparation is successfully explored. An aluminium filled epoxy resin mould is evaluated and the characteristics of the injection-moulded end products are presented.     

基于激光快速成型技术的快速模具CAD

针对基于激光快速成型技术的快速模具制造的特点,介绍了快速模具ＣＡＤ技术的有关方面,提出了一个基于激光快速成型技术的快速模具设计系统的框架,以实现面向制造的快速模具的设计。     

Instant tools [rapid tooling]

Rapid prototyping (RP) technology has attracted a lot of attention as an effective tool to compress the new product development process and hence decrease the time to market. As RP technology continues to develop, other systems and processes, such as computer integrated manufacturing and metal injection moulding, are becoming available to industry. One such technology, driven by RP, is rapid tooling (RT) which has the potential to reduce product lead times. RT can be broken into two broad classifications: indirect and direct tooling. In producing a mould tool, for example, indirect tooling would use a master pattern, such as an RP model, to produce the mould cavity, whereas direct tooling would build the mould tool directly from CAD data. The paper reviews the prospects of creating a mould tool directly from a computer model     

Rapid tooling aided by reverse engineering to manufacture EDM electrodes

The present work deals with the application of indirect rapid tooling (RT) technology to manufacture electrical discharge machining (EDM) copper electrodes from investment casting, with wax prototypes made by ThermoJet 3D printing, a rapid prototyping (RP) technique. The reverse engineering (RE) method is utilised to transform the point cloud data of an object surface, obtained from 3D digitising, in a 3D CAD surface model dataset. The methodology presented is fundamental to verify the prototype’s geometry for tooling so as to assure its metrological accuracy and to optimise foundry process parameters using finite element analysis (FEA). Based on a case study, some functional conclusions are presented for the application of RT in manufacturing EDM electrodes aided by 3D digitising and RE, validating the accomplishment by the integration of these technologies and methodologies in EDM manufacturing processes.     

Rapid Sheet Metal Manufacturing. Part 2: Direct Rapid Tooling

The traditional methods adopted for tool design and production in the sheet metal forming industry usually carry a high cost and long lead time resulting in cost justification problems for short production runs. Rapid tooling (RT) technology is capable of justifying the cost of tooling suitable for short production runs or design evaluation purposes. In Part 1 of this work, a new process termed rapid sheet metal manufacturing (RSMM) for the production of soft tooling suitable for prototyping, tool development, and short production runs was introduced. In addition, an indirect RT method employing rapid prototyping (RP), rapid soft tooling, and casting for the fabrication of non-ferrous tools was presented. The current work, Part 2, presents an alternative technique for RSMM whereby metal forming tools are fabricated directly from the RP system via selective laser sintering (SLS).     

A scaffolding architecture for conformal cooling design in rapid plastic injection moulding

Cooling design of plastic injection mould is important because it not only affects part quality but also the injection moulding cycle time. Traditional injection mould cooling layout is based on a conventional machining process. As the conventional drilling method limits the geometric complexity of the cooling layout, the mobility of cooling fluid within the injection mould is confined. Advanced rapid tooling technologies based on solid freeform fabrications have been exploited to provide a time-effective solution for low-volume production. In addition, research has made attempts to incorporate conformal cooling channel in different rapid tooling technologies. However, the cooling performance does not meet the mould engineer’s expectations. This paper proposes a novel scaffold cooling for the design of a more conformal and hence more uniform cooling channel. CAD model for constructing the scaffolding structure is examined and cooling performances are validated by computer-aided engineering (CAE) and computer fluid dynamics (CFD) analysis. An erratum to this article can be found at     

快速模具技术在摩托车齿轮箱盖制造中的应用

介绍了将快速模具技术应用于摩托车齿轮箱盖零件制造的过程,研究了纸基砂型铸造模具制作的技术方案和实施步骤,并对其中的一些技术关键进行了深入的探讨.结果表明,利用快速模具技术可以取代传统的木模制作工艺,此技术具有制作周期短、成本低、尺寸精度高的特点,适用于产品开发过程中小批量样件的快速制造.     

3D printed tooling for vacuum-assisted resin transfer moulding

Three-dimensional printing (3DP) is widely considered to be one of the low-cost additive manufacturing (AM) processes. In this paper, the suitability of 3DP for making tooling for the vacuum-assisted resin transfer moulding (VARTM) process is considered. This combination has potential advantages, since VARTM has significant prototyping benefits if it can be combined with a fast and low cost tooling option. This paper presents a new process chain for the manufacture of closed mould composite parts using the VARTM process. It will be shown that 3DP tooling is significantly less accurate than CNC machined tooling, but there is a cost and time advantage to making tooling with 3DP. The mould life is also limited to typically 15 to 30 parts since significant wear occurs in the manufacturing process. Quantitative data are presented to show the effect of treating the mould surface to improve the surface roughness and to determine the mould life. An aspect often lacking in AM research is cost estimation. Here, the first cost model for rapid tooling for VARTM using 3DP moulds is presented and compared to actual results. It is shown that the model is suitable for design for manufacture analysis.     

快速成形集成制造系统的开发与研究

快速成形制造系统以快速成形技术的核心技术,实现ＣＡＤ／ＲＥ、ＲＰ、ＲＴ的技术集成。西北ＲＰＭ应用服务中心以西安交通大学为技术依托,在工艺集成、系统精度、数据集成、远程网络化服务等方面进行研究与开发。以实际案例说明快速成形技术及以其为基础的快速模具技术在企业新产品的快速开发中的重要作用。     

基于数控加工原型的快速模具制造工艺

提出一种将常规数控加工技术与精密材料成形技术结合应用于快速模具制造的新工艺。工艺路线为在CAD环境中对零件的CAD数据进行前期误差补偿,用普通加工中心快速加工出精密成形用的专用蜡基或泡沫塑料基模具原型,并优化其加工工艺和后处理工艺,最后通过精密铸造工艺制造出模具,使之在少量加工或者不加工条件下能用于实际生产。     

基于快速成型的快速模具制造工艺分析

介绍了基于快速成型的快速模具制造技术的工艺原理、分类、成型方法、技术特点以及与传统成型方式的区别。从模具的寿命,模具的制作成本,模具的生产周期等方面对几种典型快速模具制造技术系统进行了比较和归纳。分析了快速模具制造技术面临的关键问题,展望了基于快速成型原理的快速模具制造的应用前景。     

基于Web的快速模具远程制造服务系统

数字化和网络化已成为当前制造业最为显著的生产特征。为了改变快速模具的传统制造模式为基于Internet的异地协同开发制造模式,解决逆向工程(RE)、快速成形(RP)、快速模具(RT)设备低利用率与企业得不到快速成形与制造(RP&M)技术服务的矛盾,缩短模具的生产制造周期,迎合新产品快速开发的需求。研究和开发了基于Web的快速模具远程制造服务系统。首先介绍了基于RE/计算机辅助设计(CAD)/RP快速模具开发制造系统的工作流程及其组成;然后阐述了远程制造服务系统的功能设计和关键技术的实现;最后构建了服务系统运行的Web平台。该系统旨在集成已有的RE、CAD、计算机辅助分析(CAE)、RP技术及以此为基础的快速模具制造技术,并以万维网(WWW)为支撑,以RP&M服务中心和各生产力促进中心为服务载体,以为远程用户、服务中心、协同制造企业提供方便快捷的技术信息平台、电子商务平台、制造服务平台为服务宗旨。     

快速模具技术在现代制造技术中的应用

快速模具技术随着工业化生产的发展而产生,一直受到模具界的广泛重视。文中概括地介绍了快速模具技术在现代制造技术中的应用,对于快速模具技术的应用与发展,具有重要的现实意义。     

快速成形及其在快速制模中的应用

快速成形（ＲＰ＆Ｍ）作为一种新兴的先进制造技术,已成功地实现了快速原型制造,正向快速制模（ＲＴ）方向迅速发展。本文介绍了快速成形技术的现状及其在快速制模尤其是快速金属模具制造方面的应用,探讨了制约快速制模技术发展的关键问题和该技术的发展趋势。     

快速模具制造及其应用第一讲快速模具制造的重要性及其新概念

介绍快速模具制造的新概念、重要性与现状，以及商品化的快速软模、快速过渡模和快速批量生产模的种类与寿命，讨论我国在快速模具制造方面存在的差距。     

Rapid Manufacture of Metal Tooling by Rapid Prototyping

As the race to launch a product successfully into the market increases in speed, the drive to reduce metal tooling lead time will become more important. Time reduction for fabricating metal tools depends on fast, efficient, and flexible manufacturing processes that dramatically reduce lead times while not sacrificing mechanical properties. A novel process of rapid tooling, non-baking of ceramic moulding, was studied. It uses a casting mould made from ceramic slurry and rapid prototyping to form a metal tool. It provides a quick, accurate, and relatively cost-effective route for producing metal parts or tools. The process and key technologies are analysed in detail. The process has been used in the automotive, consumer products, casting, and toy industries. Applications show that the total costs for new products can be reduced by as much as 40–60%, and lead times can be reduced by 50–60%. The surface roughness is approximately Ra = 3.2, and it can be improved to better that Ra = 1.6 by polishing. The dimensional accuracy relative to size is about ±0.1 mm for dimensions less than 200 mm. ID="A1"Correspondance and offprint requests to: Mr Z. Shan, The Centre for Laser Rapid Forming, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China. E-mail: shanzhongde@mails.tsinghua.edu.cn     

Limit analysis on surface roughness and dimensional accuracy of spray metallic crust for rapid tooling production by metal arc spraying process

Repetitively prototyping several prototypes of the same component using currently available rapid-prototyping equipment can be very costly. Substantial savings can be attained with the use of a metal spray process to produce a crust shell on a rapid-prototyping pattern coated with mould release agent (PVA), and then backing the crust with aluminium granules so as to form rapid mould/tooling (RT). The smoothness of the innermost spray layer and its dimensional accuracy in relation to the RP prototype are factors that ensure good quality of parts replicated by RT. This paper establishes a preliminary model for predicting the upper bound of the former and the lower bound of the latter, which have been experimentally verified by arc spraying zinc onto PVA. The theoretical model permits the prediction of spraying parameters for controlling the achievable surface finishing and dimensional accuracy of a spray in RT production.     

Implementation of rapid Prototyping technology — A Hong Kong manufacturing industry's perspective

Rapid Prototyping (RP) is a technology for rapid computerised building of 3D physical parts. It can be defined as an automated and patternless process which allows solid physical parts to be made directly from computer data in a short time. RP acts as the manufacturing middle to link up the computer-aided design (CAD) process and manufacturing processes. It includes the making of prototypes for design verification and even the making of tooling for production. With the trend towards concurrent engineering and the widespread use of CAD, RP has quickly become a booming business in the past few years. This paper presents an overview of the implementation of RP technology in Hong Kong and the critical decision factors in implementing RP in the Hong Kong manufacturing industry.     

Integrated Manufacturing System for Precision Press Tooling

The press tooling industry, characterised by many small-scale job-shops, is facing an increasingly competitive global market. This comes at a time when there is a shortage of experienced process planners and unavailability of affordable CAD/CAM systems that could provide an integrated solution for manufacturing sheet metal tooling. Many commercially available CAD/CAM systems are either too expensive or too narrow in scope, in the sense that they provide only point solutions. The design of press tools and its manufacturing functions are highly specialised and knowledge-intensive in nature. This paper presents a framework and the implementation details of an integrated system that has been developed for a local sheet metal tooling company specialising in precision punches and dies. A PC-based system has been implemented on an AutoCAD platform using the Autolisp programming language.     

Rapid prototyping and tooling techniques: a review of applications for rapid investment casting

Investment casting (IC) has benefited numerous industries as an economical means for mass producing quality near net shape metal parts with high geometric complexity and acceptable tolerances. The economic benefits of IC are limited to mass production. The high costs and long lead-time associated with the development of hard tooling for wax pattern moulding renders IC uneconomical for low-volume production. The outstanding manufacturing capabilities of rapid prototyping (RP) and rapid tooling (RT) technologies (RP&T) are exploited to provide cost-effective solutions for low-volume IC runs. RP parts substitute traditional wax patterns for IC or serve as production moulds for wax injection moulding. This paper reviews the application and potential application of state-of-the-art RP&T techniques in IC. The techniques are examined by introducing their concepts, strengths and weaknesses. Related research carried out worldwide by different organisations and academic institutions are discussed.