Thermoplastics

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Thermoplastics

• Brent Strong

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Thermoplastics and Thermosets
Advanced Thermoplastic
Advanced Thermoset
High Cost High temperature capabilities High
strength High modulus Good fiber wet-out Brittle
High cost Solvent resistance High
toughness Poor wet-out High strength
Engineering Thermoset
Engineering Thermoplastic
Low cost Excellent fiber wet-out Moderate
strength Brittle
Low cost Standard TP mfg Short fibers Moderate
strength Good toughness
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Engineering Thermoplastics

• Most commonly used engineering thermoplastics as
  matrices
• Nylon
• Polycarbonate (PC)
• Polyethylene terephthalate (PET)
• Polypropylene (PP)
• Stronger and stiffer but lower toughness
• Physical and chemical properties are those of the
  resin

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Engineering Thermoplastics - effect of fiberglass
Coefficient of Thermal Expansion (in/in/oF x10-5)
Izod Impact (ft-lb/in)
Flex Modulus (ksi)
Tensile Strength (ksi)
Elongation ()

• 2000 4 80 40
• 1500 3 60 30
• 1000 2 40 20
• 1 500 1 20 10

CTE Flex Modulus Izod Impact Elongation Tensile
Strength
0 10 20 30 40 50
Scales for each property
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Thermoplastic - Advantages

• Toughness
• Solvent resistance
• Re-molding
• Processing by conventional thermoplastic method
  (engineering thermoplastics with very short
  fibers)
• Processing times

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Advanced Thermoplastics

• All highly aromatic
• Most common types
• Thermoplastic polyimides (TPI, PAI, PEI, PBI)
• Polyetheretherketone (PEEK, and related)
• Sulfone and related (PSU, PAS, PES, PPS)
• Liquid crystal polymers (LCP)
• Fluoropolymers (PTFE, PVDF)

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High Performance Thermoplastics
Polyether ether ketone (PEEK)
Polyphenylene sulfide (PPS)
)
(
n

Polyetherimide (PEI)
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Thermoplastics - Problems

• Fiber wet-out (long fibers)
• Vertron concept
• Melt coating
• Film infusion
• Co-mingling fibers
• Surface powder
• High processing temperatures (especially advanced
  thermoplastics)

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Thermoplastic - Thermoforming
Press (in two modes)
Blanks
Clamp
Finished Part
Oven
Pressing
Clamping
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Thermoplastics
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Thank you

• A. Brent Strong