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Introduction to Manufacturing Processes
Pt. 2
© 2012 Project Lead The Way, Inc.Principles Of Engineering
Heat Treating Processes
Controlled heating and cooling of a material to alter its properties while maintaining its shape
Properties include: Strength, toughness, machinability, wear resistance, and corrosion resistance
90% of heat treating is preformed on steel and other ferrous metals
Heat Treating Processes
To aid in the manufacturing process, materials can be treated to be weak and ductile and then can be re-treated to provide high strength.
Can also occur incidentally during the manufacturing process
Joining and Assembly ProcessesMechanical Fastening
Use physical force to hold parts together
Mechanical fasteners or part design
Screws, bolts, nails, rivets, cotter pins, retaining clips, and edge design
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Joining and Assembly ProcessesWelding
Operations that use heat, pressure, or both to permanently join parts
Gas, arc, stud, spot, forge, roll laminating, resistance, and induction welding
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Joining and Assembly ProcessesAdhesive bonding
Bonding of adjoining surfaces by filling the gap between each surface with a bonding material
Glue, cement, thermoplastic, thermosetting, and elastomers
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Joining and Assembly ProcessesSoldering and Brazing
Operation in which metal surfaces are bonded together by an alloy
Heated molten alloy flows between the adjoining surfaces
When the heat is removed, the molten metal solidifies and the metal surfaces are bonded
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Rapid PrototypingAdditive process
Parts are produced directly from software applications
Common rapid prototyping systems include: stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), laminated object manufacturing (LOM), digital light processing (DLP)
Rapid Prototyping
Finished parts can be field tested depending upon building material
Created parts can be used to create a mold
Modifications to design can be implemented quickly
Other Manufacturing Processes
Testing
Transportation
Material handling
Packaging
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Material-Specific Manufacturing Processes
Plastic ProcessesCeramic Processes
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Plastics Manufacturing Processes
A rotating screw forces plastic through a heating chamber and then through a heated die
Produces long plastic parts with uniform cross sections
Extrusion
Heated plastic is forced by a movable plunger through a nozzle and then into a mold. The material fills the mold and then is cooled.
Most widely used high-volume production process
Plastics Manufacturing ProcessesInjection Molding
Plastic is melted and poured into a mold – No pressure or fillers are required.
Plastics Manufacturing ProcessesCasting
A closed mold is filled with a predetermined amount of plastic. The mold is heated, rotated, and then cooled to create a hollow plastic object with uniform wall thickness.
Rotational Molding
Plastics Manufacturing Processes
A solid bottom hollow tube is placed between two mold halves and heated. The heated tube is then expanded into the sides of the mold with compressed air.
Blow Molding
Plastics Manufacturing Processes
Liquid reactants are mixed and then pressurized into a mold.
No heat is needed. Curing time is typically less than 1 minute.
Reaction Molding
Plastic sheets are heated over an open mold to a working temperature. Once workable, a vacuum is applied to the mold, forcing the plastic sheet to take the shape of the mold.
Thermoforming
Ceramic Manufacturing Processes
Two distinct classes of materials and processes exist.
Glass is heated to a molten state, shaped by viscous flow, and then cooled to produce a solid.
Crystalline CeramicsMaterial is shaped and then heated to produce a permanent solid.
