polymer processing references billmeyer* ch. 17, 18 elias** ch. 14 *textbook of polymer science 2 nd...
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Polymer Processing
References•Billmeyer* Ch. 17, 18•Elias** Ch. 14
*Textbook of Polymer Science 2nd Ed.Wiley-Interscience, New York (1962,1971)**An Introduction to Polymer ScienceVCH, New York (1997)
Legacy Lecture of Fall 2000This lecture was contributed by the MS-I class of Fall 2000.
Left to RightNhan Thai, Lee Madsen, Lu Ziqiang, Zu Yichuan, Nikhil Gupta
Simon Mwongela, Andrea Dupre, Mariah McMasters, Vera Verdree, Angela Davis
Nadia Edwin, Thomas Morgan, Amy Morara, Xiaoming Liang Missing: Justin Mecomber
Not just one polystyrene
Physical Property
Test Condition
Unit Grade VEF
EF
HM
HR
HM-HR
Viscosity Number
? mL/g 74 96 119 96 119
Heat Distortion Temp B
0.45 MPa oC 80 82 84 98 98
Heat Distortion Temp B
1.8 MPa oC 70 72 76 86 86
Vicat Temp A
10 N oC 88 88 92 106 106
Vicat Temp B
50 N oC 84 84 89 101 101
Young's Modulus
1 mm/min MPa 3150 3200 3150 3200 3250
Creep Modulus
1000 h MPa ? 2300 2830 2700 2850
Tensile strength
5 mm/min MPa 46 50 56 50 63
Fracture elongation
5 mm/min % 1.5 2 2 2 3
Impact strength
-30 to + 23 oC kJ/m2 6 9 11 10 13
Notched Impact Strength
-30 to + 23 oC kJ/m2 2 2 2 2 2
Selected PS grades from BASF. VEF=very easy flow; HM=high molar mass; HR = heat resistant. Taken from Elias, Ch. 14. Processing engineers select grades using data such as these, perhaps relyingon such numbers more than the molecular data such as M or Rg that chemists are used to.
Note how completely unmolecular!What molecular properties do you suppose correspond to EF, HR or HM?
Back to the BeginningEarly in the course, we tried several ways to categorize polymers, such as condensation vs. addition, etc. From a processing point of view, the main classes are:
Thermoplastic: the resin is heated to make a viscous liquid and then processed into a usable object without much additional chemistry. Example: polyethylene, polystyrene.
Thermoset: upon heating, further reaction occurs to make molecules “set up” into a useful product. Chemistry occurs, so these are sometimes called “reactive polymers”. The resin may be provided as either small molecules or “prepregs”—partially polymerized stuff. Example: polyurethanes, phenol-formaldehyde, melamine-formaldehyde, epoxy glue.
Compression Molding
Redrawn by Nikhil Gupta and Yichuan Xu from Billmeyer Fig. 17-1
Platen
Mold Plunger
Guide Pins
Mold Cavity
Platen
Hydraulic Plunger
Heat and Cooling
Heat and Cooling
Hydraulic Pressure
Compound to be molded
Injection Molding
Hydraulic Pressure
Nozzle
Redrawn by Ziqiang Lu and Andrea Dupre from Billmeyer Fig. 17-2
Feed hopper,contains polymer pellets
Blow Molding—e.g. milk bottle
Extruded Parison-Mold Open
Mold Closed and Bottle Blown
Finished Bottle Removed from Mold
Plastic
Redrawn by Thomas Morgan from Billmeyer Fig.17-3
Four-roll calender Wad of plastic
To conditioningequipment
Based on Billmeyer Fig. 17-4 (references Winding 1961)
A Plastics Extruder—e.g. tubing
Feed hopper
HeatersCores for
cooling water
Die
Screw
Drive shaft
Redrawn from Billmeyer 17-5 by Xiaoming Liang
Fiber Drawing
Drive roll
Heater (Optional)
Drawn yarn to bobbin
Undrawn pretwisted yarn
Control rolls
Snubbing pin
Skewed idler roll1
2
(2 > 1)
Stretching Zone
Redrawn by Nadia Edwin from Billmeyer 18-5 (Riley 1956)
Mel
t S
pinn
er
Redrawn by Lee Madsen From Billmeyer 18-4, citing Riley 1956
Bobbin
Extruded Fiber Coolsand Solidifies Here
Metered Extrusion(controlled flow)
Melting Zone
Polymer Chips/Beads
Pump
Filter and Spinneret
Air Diffuser
Heating Grid
Pool
Lubrication by oil disk and trough
Packaging
Bobbin drive
Yarn driver
Feed rolls
Moisture Conditioning Steam Chamber
Feed
Filtered polymer solution
Metered extrusion Pump
Filter and spinneret
Solidif ication by solvent evaporation
Heated chamber
Lubrication
Air inlet
Feed roll and guide
Yarn driving
Balloon guide
Packaging
Ring and traveler
Bobbin transverse
Spindle
Dry Spinning
Dry
Spi
nnin
g of
Fib
ers
from
a S
olut
ion
Wet Spinning (e.g. Kevlar)
Cotton
Dry Spun Acetate
Need tenacity vs. ElongationPlot—a Student Project like
Billmeyer 18-1
Fiber properties for textile useChemical Physical Biological Fabric Qualities Stability to: Acid Base Bleach Solvents Heat Sunlight Aging
Mechanical Tenacity Elongation Stiffness Flex cycles Abrasion
resistance Work recovery Tensile recovery
Toxicological Dematological Resistance:
Bacteria Molds Insects
Appearance Drape Hand Luster (Kawabata machine can measure)
Flammability Thermal Melting Point Softening Point Tg Tdecompose
Permeability Can protect
against biotoxins?
Comfort Warmth Water sorption Moisture
retention Wicking
Ease of drying Electrical Surface
resistivity (static)
Sensors Can detect
pathogens?
Stability Shape Shrinkage Felting Pilling Crease
resistance or retention
Wetability
Adapted from Billmeyer Table 18-1.
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