1. Topic 4 – Manufacturing Processes and Techniques Fall 2006

2. 4.1 Manufacturing Processes and Techniques Manufacturing Process Manufacturing Technique Shaping –Bending - http://manufacturing.stanford.edu/hetm.html (Forming Shaping)http://manufacturing.stanford.edu/hetm.html –Molding - –Casting - http://manufacturing.stanford.edu/hetm.html (casting Metal)http://manufacturing.stanford.edu/hetm.html –Weaving Joining –Fasteners – screws, nail, rivets, welds, etc. http://manufacturing.stanford.edu/hetm.html (welding) http://manufacturing.stanford.edu/hetm.html –Adhesives –Fusing –Stitching Wasting - http://manufacturing.stanford.edu/hetm.html (machining)http://manufacturing.stanford.edu/hetm.html –Machining –Cutting –Abrading

3. 4.2 Selecting Materials and Techniques The selection of materials takes into account economic processing and service requirements. Successful products should be evaluated in term of efficiency and economy of manufacture as well as performance

4. Techniques Injection Molding - Lamination Sintering Extrusion Cutting and Machining

5. Injection Molding Injection Molding The direct introduction of molten plastic under pressure into a die which then cools rapidly allowing the formed object to be released from the mold Advantages –No finishing required, volume production, use of different molds Disadvantages –Set up costs reduce suitability for low volume production, limitations to the size, shape Design Considerations – must consider thermal expansivity and toughness

7. Lamination building up a thick layer of material using thin layers of the material joined with adhesives includes mold or former and a method of cramping Advantages – no finishing required, able to form complex shapes and surfaces, can suit large surfaces, able to combine different materials Disadvantages – labor intensive, may require production of a mold, limitations to the glue, size, clamping, shape and angles of curvature. Design Considerations – Good when needing a tough and high tensile strength.

8. Sintering The fusing of solid particles together by heat and pressure without completely liquifying the particles Advantages Disadvantages Design Considerations

9. Extrusion Forcing material through a shaped die to produce a shaped rod or tube of material, eg: wire, pasta, toothpaste Advantages Disadvantages Design Considerations

10. Cutting and Machining Cutting and Machining Cutting a material into shape and finishing it by machines Advantages Disadvantages Design Considerations