This document provides information on various manufacturing processes including powder metallurgy, ceramics manufacturing, glass manufacturing, traditional manufacturing processes, plastics history, types of plastics, and plastics processing techniques like extrusion and blow molding. The key steps of powder metallurgy include powder production, blending, compaction, sintering and finishing. Glass sheet making uses rolling of molten glass while bottles are made via a blow molding process with a three-piece mold. Plastics can be thermoplastics or thermosets and common processing methods are extrusion and blow molding.
2. Powder Metallurgy, Manufacturing with Ceramics
Fine powder (plastic, ceramic, metal)
Join powder particles(heat to just below melting point)
balls used in ball-pointpens
gears, cams
cuttingtools (inserts)
porousmetal filters
oil-impregnated bearings
piston rings in engines
Shape by compacting in a die
3. P-M: (1) Powder Production
Atomization:Spray liquid metal using high-pressure water, inert gas
Chemicalmethod:Pass CO or H2 gas over powdered Metal oxide (reduction)
Electrochemical action: Solutionof metal salt →
Current →
Metal depositson cathode
water atomizer air atomizer
4. P-M: (2) Powder Blending, (3) Powder Compaction
Blending
• Mix different sizes of powder homogeneously
• Add lubricant to improve compaction die life
Compaction: produces green mold
5. P-M: (4) Sintering, (5) Finishing
Green compact → heated in oven to 70% ~ 90% of melting point → Diffusion weld
Sintering:
3-stage Sintering furnace: burn off lubricant→ sinter → cool down
Finishing:
1. Coining and sizing: forging die to improve dimensional accuracy
2. Impregnation: e.g. oil impregnation for self-lubrication bearings
3. Infiltration: e.g. brazing of steel powders to add strength
6. Manufacturing with Glass (and Ceramics)
Glass Sheet making: Rolling operationusing molten glass
Lenses, Headlamps manufacture:Moldingprocess
Glass tubes and rods: Drawing process using molten glass
7. Bottle manufacture
heated glass
3-piece mold
(a) Thehollowpiece of heated glass (parison)
is first created bya blowmold
(see text-book Fig 17.25)
(b) Themold is put together
(c) Plunger and hot air pushthe
glass up
(d) Hot air blows the glass out towards
themold surface
(e) Mold comes apart, bottle is removed
heated glass
3-piece mold
(a) Thehollowpiece of heated glass (parison)
is first created bya blowmold
(see text-book Fig 17.25)
(b) Themold is put together
(c) Plunger and hot air pushthe
glass up
(d) Hot air blows the glass out towards
themold surface
(e) Mold comes apart, bottle is removed
Blow molding
source: http://www.pct.edu/prep/bm.htm
11. Plastic types: Elastomers
Generalproperties:these are thermosets, and have rubber-likeproperties.
Typicaluses:medical masks, gloves, rubber-substitutes
Examples:
Polyurethanes: mattress, cushion, insulation,toys
Silicones: surgical gloves, oxygen masks in medical applications
joint seals
12. Generalproperties:low melting point, softer, flexible.
Typicaluses:bottles, food wrappers, toys, …
Examples:
Polyethylene: packaging, electrical insulation, milk and water bottles, packaging film
Polypropylene: carpet fibers, automotive bumpers, microwave containers, prosthetics
Polyvinyl chloride (PVC): electrical cables cover, credit cards, car instrument panels
Polystyrene: disposable spoons, forks, Styrofoam™
Acrylics (PMMA: polymethyl methacrylate): paints, fake fur, plexiglass
Polyamide (nylon): textiles and fabrics, gears, bushing and washers, bearings
PET (polyethylene terephthalate): bottles for acidic foods like juices, food trays
PTFE (polytetrafluoroethylene): non-stick coating, Gore-Tex™ (raincoats), dental floss
Plastic types: Thermoplastics
13. Plastics Processing: Extrusion
p e lle t s
o p e n c r o s s - s e c t io n s ( c h a n n e ls ) c lo s e d c r o s s - s e c t io n s ( t u b e s , p ip e s ) p e lle t s
o p e n c r o s s - s e c t io n s ( c h a n n e ls ) c lo s e d c r o s s - s e c t io n s ( t u b e s , p ip e s )
14. Plastics Processing: Blow molding
heated glass
3-piece mold
(a) Thehollowpiece of heated glass (parison)
is first created bya blowmold
(see text-book Fig 17.25)
(b) Themold is put together
(c) Plunger and hot air pushthe
glass up
(d) Hot air blows the glass out towards
themold surface
(e) Mold comes apart, bottle is removed
heated glass
3-piece mold
(a) Thehollowpiece of heated glass (parison)
is first created bya blowmold
(see text-book Fig 17.25)
(b) Themold is put together
(c) Plunger and hot air pushthe
glass up
(d) Hot air blows the glass out towards
themold surface
(e) Mold comes apart, bottle is removed
- similar to glass blow-molding-
