<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.     

Rapid prototyping versus virtual prototyping in product design and manufacturing

Rapid prototyping (RP) is the production of a physical model from a computer model without the need for any jig or fixture or numerically controlled (NC) programming. This technology has also been referred to as layer manufacturing, material deposit manufacturing, material addition manufacturing, solid freeform manufacturing and three-dimensional printing. In the last decade, a number of RP techniques has been developed. These techniques use different approaches or materials in producing prototypes and they give varying shrinkage, surface finish and accuracy. Virtual prototyping (VP) is the analysis and simulation carried out on a fully developed computer model, therefore performing the same tests as those on the physical prototypes. It is also sometimes referred to as computer-aided engineering (CAE) or engineering analysis simulation. This paper describes a comparative study of the two prototyping technologies with respect to their relevance in product design and manufacture. The study investigates the suitability and effectiveness of both technologies in the various aspects of prototyping, which is part and parcel of an overall design and manufacturing cycle.     

快速成形转向快速生产的主要障碍

快速成形制造 (RPM)技术是国外 80年代后期发展起来的一门新兴综合技术。它使直接从概念设计迅速转为产品设计的生产模式成为可能 ,工业界正在探索使用快速成形机器生产最终要制造的零件的问题。但是 ,它面临诸如材料性能、表面质量、零件的尺寸规格和成形速度等许多挑战。一旦克服了这些障碍 ,快速成形就将转向快速生产 ,并将促进大量定制生产模式的加快实现     

系统快速成型技术

为了加速机械系统的设计与开发流程,提出一种新的产品系统设计方法,称为系统快速成型(Rapid Prototyping of System,简称RP-S)。RPS与快速成型技术(Rapid Prototyping,简称RP)相仿,使用塑料为主要原材料。RP的最终产品是单个部件的模型,因此本文中称其为(Rapid Prototyping of Components,简称RP-C)。而RP-S基于一种模块化塑性模块(Modular Plastic Module,简称MPM)来构成整个产品系统的模型。RP-S能加快产品系统的设计速度,从而提高生产效率。     

快速成型技术工艺特点及影响精度的因素

快速成型是一种基于离散堆积成型思想的数字化成形技术,可以在无需任何模具、刀具和工装的情况下,直接从CAD数据,快速制造出具有任意复杂形状的实体部件。介绍了快速成型领域四种典型的成型技术及其加工原理,阐述了其加工过程中所具备的快速性和高度柔性等现代化制造特点。比较了典型快速成型工艺的适用领域、加工成本和技术参数,找出影响成品精度的工艺及设备方面因素。分析各种成型技术在成形精度、表面质量、材料成本等方面的优点和缺点。     

RE&RP一体化技术在工业设计中的应用研究

阐述了反求工程和快速成型的概念,论证了反求工程和快速成型技术一体化在现代工业设计中应用的意义和模式,并从扫描模型的建立、数据采集、数据处理、CAD模型的重建、产品的再设计与快速成型技术等方面,对反求工程和快速成型一体化具体应用过程进行了比较详细的分析和研究。将反求工程与快速成型一体化技术应用于现代工业设计中,改变传统的产品开发设计、制造模式,从而大大缩短产品开发周期。     

Friction and wear behaviour of rapid prototype parts by direct metal laser sintering

Abstract

Rapid prototyping and manufacturing (RP/M) is one of the proven tools for product development owing to its advantages such as short product cycle, high quality product and possibility of fabricating functionally gradient materials. Several RP/M techniques do exist. Among them, direct metal laser sintering (DMLS) method is quite popular as near net shape components with high dimensional accuracies can be manufactured. Meager information is available as regards the tribological behaviour of laser built parts, although this is vital in judging the suitability of built-up parts for applications where sliding is inevitable. In the light of the above, the present investigation is aimed at building parts by DMLS technique of RP/M using 50 μm iron powder and characterising its density, microstructure, microhardness, tensile strength, friction and wear behaviour under sliding conditions. The effect of laser speed on the above properties of built-up parts has been studied. The build layer thickness was maintained at 50 μm. Laser diameter of 0˙4 mm, laser power of 180 W and hatch spacing of 0˙2 mm were adopted. However, the laser speed was varied from 50 to 125 mm s^–1 in steps of 25 mm s^–1. Laser speed had a profound influence on density, microstructure, microhardness, tensile strength, friction and wear behaviour of built-up parts. Lesser laser speed resulted in higher density, microhardness, tensile strength and wear resistance while higher laser speed promoted lowering of coefficient of friction.     

Rapid prototyping in the development of optical pickup unit

Rapid prototyping (RP) has already proven itself in the electronics industry as a method for shortening the product development time cycle. In the development of the optical pickup unit (OPU), extremely high precision is needed to make a functional model. Very often, in the design phase of the product development cycle, the prototype of the OPU is machined from a single piece of aluminium block to make the working sample. In this project, a comparison of the machined aluminium sample, RP samples from various RP processes and that moulded out from the injection moulding machine is made on surface finishing as well as dimensional accuracy. Finally, a comparison of tooling cost, piece part cost and lead time of obtaining the parts is also discussed on the different prototyping and manufacturing processes.     

Solid ideas [rapid prototyping]

Rapid prototyping is fast becoming one of the essential technologies that allows manufacturers to improve product quality and reduce both time to market and the cost of new lines, as part of a concurrent engineering strategy. RP technologies can be virtual (soft/CAD-based) or physical (hard). Physical RP allows designers to build tangible models of their designs quickly and cheaply. This encourages experimentation, and flags errors in the fit or assembly of the part. This article looks at the existing physical rapid prototyping technologies     

Optimization of stereolithography process parameters for part strength using design of experiments

Rapid prototyping (RP) is an emerging technology that has been implemented in many spheres of industry – particularly in the area of new product development. Growth of this field has been rapid in recent years. Stereolithography (SL) is one of the most popular RP process used for rapid tooling applications. There are several process parameters contributing to the strength of an SL product. The contribution of three parameters; namely, layer thickness, post curing time and orientation are most significant. In light of this concern, an attempt has been made to study and optimize these process parameters for maximum part strength, and develop an empirical relationship between process parameters and part strength through design of experiments (DOE). The proposed DOE is verified with the data of experiments conducted under standard conditions.     

激光熔敷快速制造技术及其精度保证分析

RP技术在当今市场上有较强的优越性。本文分析了快速成型系统的成型原理;重点分析了一种新型激光熔敷快速成型系统;介绍了STL格式模型和利用RP技术的快速性和铸造工艺的成熟性制造功能性产品的CAE系统;并构建了多回路误差控制及反馈系统,从而保证系统的精度。     

Rapid prototyping fabrication and finite element evaluation of the three-dimensional medical pelvic model

This paper presents a non-uniform, periodic closed B-spline approximation algorithm for the fabrication of a medical pelvic model, based on rapid prototyping, and also gives the finite element evaluation of the pelvic model. Rapid prototyping (RP), when used in fabricating medical prosthesis, has a strict requirement for closeness and impermeability of STL files. Incorrect data structure in STL files will cause the subsequent slicing process not to proceed. The non-uniform periodic closed B-spline curve approximation method was applied to processing CT data. The precision and size of STL files was improved to optimize the RP model of the pelvis. Finally, the model of the pelvis was evaluated with the finite element method. Results suggest that a high similarity has been achieved in terms of shape, size and biomechanical properties of the pelvic model and the normal one, which validates our argument that rapid prototyping with non-uniform, periodic closed B-spline algorithm is suitable for the fabrication of a pelvic model, which will prove to be significant in the design of pelvic prostheses .     

Rapid Prototyping and Tooling of Custom-Made Tracheobronchial Stents

Rapid prototyping (RP) and rapid tooling (RT) techniques can be applied to the field of medicine primarily because of their ability to produce customised profiles and geometries in relatively short lead times. In this paper, the process by which these techniques can be applied for the production of customised tracheobronchial stents for the purpose of maintaining patency in an occluded respiratory tract is described. A comparison of RP systems was carried out to establish the preferred RP method to produce the master model. The vacuum casting RT process was then used to produce the stent.     

Fast tooling

Rapid prototyping (RP) has become a popular and well-known technique for speeding time-to-market. The next step, rapid tooling, promises the same benefits but poses rather more problems. A development project is described. Rapid tooling is a technique that draws on both existing RP technologies and traditional engineering techniques, such as pattern making. Parts are manufactured via the intended production route and produced in the required production material. Laminated sheets are cut and assembled, then machined further to get a precise result. Problems of tooling pressure and accurate lamina assembly are considered     

Plaster casting process for prototyping of die casting based on rapid tooling

Rapid prototyping (RP) combined with a gravity casting process can provide a suitable substitute with steel tool die casting for prototyping metal casting. Due to differences between die casting and gravity casting, there are several drawbacks in RP simulated die casting. This paper is concerned with the development of a new plaster die casting process that combines pressurization and vibration for prototyping of die castings, and with a plaster die casting machine that has a structure similar to that of a die casting machine. The machine utilizes an oil cylinder for pressurization and a magnetic actuator for vibration. A rapid prototyped pattern is made by the laminated object manufacturing (LOM) process to prepare a plaster mold. In the process, a plunger in the developed machine simultaneously pressurizes and vibrates the molten metal to fill the plaster mold completely and to facilitate the creation of nuclei in the molten metal, respectively. The developed machine has produced a prototype of an end clutch cover with remarkable improvement in mechanical properties.     

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     

一种经济型快速成形系统的构成及分析

针对快速成形（RP）技术昂贵的研究和使用成本限制了该技术在我国推广应用的问题,从中小企业的实际技术条件出发,分析论证了以数据机床或加工中心等数控设备为基础构成经济型快速成形系统的可行性和现实意义。     

基于快速原型技术的产品创新流程再造

指出了基于快速原型技术产品创新过程中的信息流动是以数字信息为主,从而为创造信息化流程提供了良好的基础条件,并在分析传统职能部门型组织弊端的基础上,讨论了基于快速原型技术产品创新流程的三种常见基本组织形式,分析了其基本功能并对其本质特性进行了详细的研究.     

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。     

Measurement of some properties of binderless composites manufactured from oil palm trunks and Acacia mangium

The objective of this work was to evaluate properties of experimental particleboard panels manufactured from oil palm (Elais guineensis) trunks and Acacia mangium. Samples were made having five different ratios of two types of raw materials without using any adhesives. Both physical and mechanical properties of the specimens were evaluated based on Japanese Industrial Standards (JIS). Panels made with 100% oil palm particles had the highest modulus of rupture and internal bond strength values of 22.91% MPa and 0.59 MPa, respectively. Addition of A. mangium particles in the panels adversely influenced their mechanical properties while improved both thickness swelling and water absorption of the specimens. All panels made in this work met minimum strength requirements stated in JIS. Based on the findings in this work it appears that both types of underutilized species could have a potential to be used as raw material to manufacture binderless value-added panels.