1、CARFUL RAPID PROTOTYPING AND MANUFACTURINGFIRST Introduction Carful Co., Ltd. was found in 2002, adhering to the spirit of “professional, high-quality, efficient, honest “and “quality assurance, reasonable price, prompt delivery, thoughtfully service“ for the principle, after the exertion and innova
2、tion in recent years, we has developed into a professional and experienced company that include rapid prototyping, model making, small batch processing, Reverse Engineering,product and structure design, etc. also we can provide you one-stop service that include molding ,injection, manufacturing and
3、assembling. We have an excellent team which can provide you with efficient and reliable technical service and support. The term “rapid prototyping” (RP) is a relatively new expression for the generation of three-dimensional models manufactured without the need for machining or products designed on a
4、 computer aided design system, the first rapid prototyping system was introduced on to the US market in 1988 and gave the engineer the opportunity to produce 3 dimensional objects directly from Computer Aided Design (CAD) date and succeed in the cost-effective production of patterns and moulds with
5、complex surfaces.The principle advantages of using this technology are:1.High speed at which the solid model is generated.2.The complexity of the model does not form any limitation to its production.3.The early use of these models was to assist the designer in determining fitness and form. It also p
6、rovided the sales team with a 3 dimensional object to show to a prospective customer, this being far better than the traditional orthographic drawing which many people find difficult to interpret.The benefits of RP:1.Converts 3D CAD images into accurate physical models at a fraction of the cost of t
7、raditional methods.2.Improves design communication and helps eliminate design mistakes.3.Reduces “time to market” for a new product.4.Can be used as a powerful marketing tool since the prototype can be seen rather than the drawing.5.The development of this technology has reached into many of the tra
8、ditional fields, attracting the interest of artisans whose skill any knowledge has led to 3-D objects being used directly and indirectly as patterns and model for soft tooling. 6.Production of models by machining has a number of limitations.7.Material removed during forming is difficult to reclaim.
9、8.Machining in the form of drilling turning milling spark erosion etc., is limited by the shapes it can produce.9.In the event of design change, conventional tooling such as patterns ,core boxes, dies, jigs etc. ,become expensive to alter ，and in many cases, may require complete re-manufacture.10.Ra
10、pid prototyping differs with conventional manufacturing methods by adding material layer by layer until the desired sharp is achieved, immediately reducing or avoiding the loss of material.What RPM CAN DO?To substantially shorten the time for developing patterns, moulds, and prototypes, some manufac
11、turing enterprises have started to use rapid prototyping methods for complex patterns making and component prototyping. Over the past few years, a variety of new rapid manufacturing technologies, generally called Rapid Prototyping and Manufacturing(RPM),have emerged ;the technologies developed inclu
12、de Stereo lithography (SL), selected laser sintering(SLS),fused deposition modeling(FDM),laminated object manufacturing(LOM),and three dimensional printing (3D Print).They have a common important feature ;the prototype part is produced by adding materials rather than removing materials. This simplif
13、ies the 3D part producing processes to 2D layer adding processes so that a part can be produced directly from its computer model. Flag1.1THE BASIC PROCESS IN RPRP machines process CAD data by slicing the computer model into layers ,each layer being typically 0.1-0.25mm thick the machine then uses th
14、is data to construct the model layer by layer ,each layer being bonded to the previous until a solid object is formed. Due to this laminated method of construction a stepped surface is developed on curved faces, the removal of which is essential if maximum advantage of the process is to be realized.
15、 Schematic representation of the stepped construction, which requires post processing.DEVELOPMENT More recent developments have been prompted by problems caused by the expansion of the model where it is used as a disposable pattern (like the wax pattern in the lost wax process), Where the resin mode
16、l is produced to form solid walls, expansion during the “burning-out” stage weakens the ceramic shell, and can cause failure in the firing and/or casting stages.The company, 3D System GmbH, has developed a machine and software, which together allow for the model to be constructed in the form of a ho
17、neycomb. The honeycomb structure collapses in on itself during “burning-out” thus avoiding the problems of expansion. Each pocket of the honeycomb structure is connected to its neighbor by a small hole that allows for the uncured resin to be drained prior using.Other methods of producing tooling dir
18、ectly from the rapid prototype-such as metal spraying are also being developed, and this seems to have potential in the production of less complex parts, although it is inevitable that some detail will be lost.Prototyping Company ARRK EUROPE LTD, London, has developed a thin layer technology, which
19、removes many of the inaccuracies inherent in mechanical finishing. It claims to be the first company in the world to achieve 0.05mm layer build accuracy.ARRKs development team used a combination of subtle mechanical alterations to setting up of its four stereo lithography (SL) rapid prototyping mach
20、ines and proprietary techniques to over come de-wetting. It also called upon its knowledge of resins.Using this new technology, the company is now able to produce extremely accurate high-quality master parts and tooling. With 0.05mm layer, the build is more precise and all but eliminates the stair-s
21、tepping effect. In addition, the need for finishing is dramatically reduced. Current Application Areas of RPMDesign Engineering (1) Visualization With RPM, the prototype of a complex part can be built in short time, therefore engineers can evaluate a design very quickly, for it isnt difficult to vis
22、ualize exactly what the actual complex product will look like.(2) Verification and optimizationImproving product quality is always an important issue of manufacturing. An RPM prototype can be produced quickly without substantial tooling and labor cost. As a result, the product quality can be improve
23、d within the limited time frame and with affordable cost.(3) Iteration With RPM technology, it is possible to go through multiple design iterations within a short time and substantially reduce the model development time.Manufacturing We can use the RPM prototype for productively studies. By providin
24、g a physical product at an earlier design stage, we can speed up process planning and tooling design. In addition, by accurately describing complex geometry, the prototype can help reduce problems in interpreting the blue prints on the shop floor. It can also be used in tooling development for mould
25、 and master pattern for castings.Marketing To assist product sales, a prototype can be used to demonstrate the concept, design ideas, as well as the companys ability to produce it. The reality of the physical model illustrates the feasibility of the design. Also, the prototype can be used to gain cu
26、stoms feedback for design modification so that the final product will meet customs requirement.RPM能做什么？为了缩短开发的样式、模子和原型的时间，一些制造业企业开始对于一些复杂部件的制造和成型的部分使用快速成型的方法。在过去几年，各种各样新快速制造业技术，通常称为快速成型制造（RPM），已经涌现了；被开发的技术包括立体印刷(SL)，有选择性的激光焊接(SLS)，塑造(FDM)，薄片叠加快速成型 (LOM)，和 3D打印(3D Print)。他们有一个共同的特点; 原型零件是通过材料的叠加，而不是材
27、料的去除形成的。这阐述了三维图形是由二维图形的叠加产生的，以便零件可以直接地由它的计算机模型生产。 快速成型的基本过程快速成型的机器是通过将计算机模型进行切片处理，每层有 0.1-0.25毫米厚。然后机器使用这些数据一层一层的叠加，每一层都将被塑造成以前的样子，直到立体模型被生产出来。由于这种方法是在一个有弯曲表面的台阶的表面生成的，生产过程的优点被了解了，那么其中是根本的将被撤除，有台阶建筑的图示，是要求分步处理的，改进产品质量一直都是制造业的一个重要问题，快速成型制造能够快速的生产而不用坚硬的工具和人工成本。结果，产品质量可以在有限的时间和有限的经费下得以改进。（3） 叠代运用快速成型和制
28、造技术，在短时间内审阅多样的设计叠代，并可能极大地减少了式样研制时间。制造我们可以为有生产力地使用快速成型和制造原型学习。通过提供一个早期设计实际产品在，我们可以快速处理计划和刀具设计。另外，通过准确描述复杂的几何形状，这样的原型在实际生产中能更好的解释方案。它也可以被用于工具朝模子和主模浇铸的方向发展。营销要协助产品销售，原型可以用于展示产品的概念和设计思路，也更能表达公司的想法。真实的物理模型能说明设计的可行性。并且，原型可以用来获取顾客的反馈，并用于后期设计修改，以便最终的产品能符合顾客的要求。凯福专家论坛讲座。地址：www.prototype-凯福精密制造的经验告诉我们快速成型这个术语
29、是对于不通过机器和工具的三维造型生产而产生的一种新的相关的表示.通过快速生产的准确能力，用电脑设计系统切实的帮助造型的设计生产。最早的快速成型系统于 1988年在美国的市场内诞生，并带给了工程师一种通过 CAD 来设计三维实物方法的机会，且成功的生产出复杂表面的模型。这项技术的操作优势如下:1.实现固态模型的高速产生。2.复杂的模型在生产中不再受限。3.最早使用这些模型是用来帮助设计者决定形状和框架。它也能为顾客提供一个三维显示的实物,这将远远优于那些很多人发现很难去解释的传统的平面图形。快速成型的好处:1.用相当于小部分传统方法的花费把准确的物理模型转化成三维影象。2.改进设计的讯息帮助并纠
30、正设计时产生的错误。3.缩短了新产品上市的时间。4.自从原理图能被理解更好的理解后，它就能作为一种强有力的工具。5.这种技术的发展已经涉及到了许多的传统领域，吸引了众多对这类知识有浓厚兴趣的人，他们直接地和间接地使用了这种技术。6.机械化生产模型有一定数量限制的。7.在成形期间被除去的材料是难回收的。8.用机器在进行例如钻微细孔等时， 它的生产受限于其形状。9.在设计变动的情形下，常规机床山的工具，例如样式，核心装箱，模子，夹具等， 都会变得昂贵以至于难于改变，并且在许多情况下，可能会被重新制造。10.快速成型不同于以通过增加物质层数的常规制造方法，直到达到所期望的锐利程度，立刻减少或避免材料
31、的损失层数。 未来的发展更多的发展由与模型的扩展而引起的问题已经提示了，使用它就像一个一次性部件(象蜡本身在失去蜡过程中)，哪里的合成树脂模型被用来形成坚实的墙壁，扩展在“燃烧”阶段期间来减弱陶瓷的外壳，并且在生火和铸件阶段都能导致失败。3D系统 GmbH公司，已经开发了相应的机器和软件，允许模型以蜂窝的形式被叠加生产。 蜂窝结构在本身被“燃烧”时，也相应的融化了，因而避免了扩展的问题。 蜂窝结构的每个口袋通过一个小孔连接到它的旁边，从而考虑到未固化的树脂在使用之前被排泄出去。其它快速成型的方法，比如金属喷镀，也被开发，并且这在较不复杂零件的生产中，看上去似乎更有潜力，但不可避免的一些细节将会
32、丢失。在伦敦的 ARRK快速成型有限公司，已经开发了薄片技术，这解决了很多在机械加工中机器的不准确性。他们宣称他们是世界上第一家能够达到切片 0.05毫米厚度的准确制造企业。ARRK的开发小组使用了微妙的机械改变的组合到它的四个立体印刷(SL)，快速成型的机器安装，并且私有的技术去克服湿度。 它也要求了对于树脂的知识。使用这种新技术，该公司现在已经能够生产超精细搞质量的主要零件和工具。 以 0.05mm厚度的层叠加，所有的制造都是精确的，除了消灭台阶跨步的作用。 另外，显著减少了对精整的需要。目前快速成型制早的应用领域：设计工程（1） 形象运用快速成型和制造技术， 一个复杂部分的原型在短期可以被制作，因此工程师能非常迅速的评估设计，因为这很难确切的使实际复杂的产品看上去形象化。（2） 证明和优化
