Computer aided design molding

Developments. A variety of process modifications aimed at improving surface finish or weld line integrity have been described. They include gas assisted, co-injection, fusible core, multiple Hve feed, and push—pull injection mol ding (46,47). An important development includes computer-aided design (CAD) methods, wherein a proposed mold design is simulated by a computer and the melt flow through it is analy2ed (48). 

K.K. Wang, S.F. Shen, C. Cohen, C.A. Hieber, T.H. Kwon, and R.C. Ricketson. Computer aided design and fabrication of molds and computer control of injection molding - progress report no. 11. Technical report, Cornell University, 1985. 

An elastomeric stamp or mold with relief structures on its surface is the key to soft lithographic techniques (see Sect. 3.2). As a result, the utility of these techniques is often limited by the availability of appropriate masters. In general, the masters are fabricated using photolithography. Chrome masks are available commercially from custom fabricators,but the time required for vendors to produce a chrome mask from a design presented in a computer aided design (CAD) file can be weeks, and they are expensive ( 300 per square inch for features larger than 20 pm, and 500 - 1000 per square inch for features between 1 and... 

Computer-Aided Injection Mold Design and Manufacture,... 

CAD 17 Center gating 39 Chamfer 100 Charpy test 28 Checklist, product 109 Clamping mechanism 42 Collapsible cores 85 Compression molding 5 Compressive strength 28 Computer-aided design 17 Concept review 20 Container, deep 34 margarine 24 pail 79... 

Rapid prototyping (RP) or solid freeform fabrication (SFF) is a relatively recent approach to forming ceramic components. There are various forms of RP techniques, but they are based on a common principle a computer directly controls the shaping process by accessing computer-aided design (CAD) files. We can thus use RP to form a 3D component without the use of a die or a mold. RP techniques are used commercially for fabrication of parts from polymers for design verification and form-and-fit applications these techniques have more recently been applied to forming parts out of ceramics. 

The described mold specifications clearly indicate the complexity of the designer s tasks. In his work, designers are assisted by numerous computerized aids. Computer-aided design has become fully established and widely accepted by now. This is not least due to the increased efficiency of affordable PCs and work stations. 

For the geometrical layout of a mold, CAD (Computer Aided Design) systems are available nowadays, with which an injection molding tool cannot only be described by two-dimensional drawings, but also shown as a complete 3-D model. The latter is of particular interest for the description of the often complex, shape-giving mold contours. The input for producing such a model... 

Making a mold is expensive and it should be checked for fit by experimental injection runs, vmtil the exact dimensions are attained. Currently computer aided design and production (CAD/CAM) are very helpful, but the expertise of the mold maker should never be underestimated. 

The flow and heating analyses that have been developed into CAD (computer aided design) systems for IM (Chapter 2) are now also being applied in CM and TM. They facilitate the construction of molds, by locating cavities, sizing runners, and locating heater lines (electric, steam, etc.) and other devices to meet cost/performance objectives (1, 82, 110-112). 

Computer-aided design (CAD) n. Using a computer, and appropriate programs (software), in the engineering design - even to the production of finished working drawings - of parts, tools, molds, and assemblies. 

Kabanemi KK, Crochet Ml (1992) Thermoviscoelastic calculation of residual stresses and residual shapes of injection molded parts. Int Polym Process 7 60-70 Kaelble DH (1985) Computer-aided design of polymers and composites. Marcel Dekker, New York... 

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