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Transcript of What Went Wrong – Polymer Failure Analysis Went Wrong – Polymer Failure Analysis . Jeffrey A....

  • What Went Wrong Polymer Failure Analysis

    Jeffrey A. Jansen ANTEC 2014

    Polymer Failure Analysis Using FT-IR and Other Techniques

  • FTIR Applications to Failure Analysis

    Material identification of failed part Qualitative assessment of polymer

    copolymers and blends Identification and verification of resin

    formulation ingredients Identification of material contaminants Determination of molecular degradation Identification of chemical agents in contact

    with failed part

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

  • FTIR in Failure Analysis The Madison Group 608-231-1907

    The goal of the failure analysis is to identify

    the Mechanism and Cause

    of the failure Visual Techniques Analytical Techniques

    FTIR Applications to Failure Analysis

    Jeffrey A. Jansen jeff@madisongroup.com

  • Plastic Seal Plastic seal in high-

    temperature chemical application specified to be produced from Vespel SCP 5000 Polyimide specialty grade

    FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

    Chemical Seal

  • Plastic Seal Plastic seal in high-

    temperature chemical application specified to be produced from Vespel SCP 5000 Polyimide specialty grade

    QC FTIR testing used to verify received lots

    Internal library established

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

    Vespel SCP 5000 Polyimide

    Exemplar Seal

  • Plastic Seal Plastic seal in high-

    temperature chemical application specified to be produced from Vespel SCP 5000 Polyimide specialty grade

    QC FTIR testing used to verify received lots

    Internal library established Nonconformance detected Field issues avoided Appearance and MP: no

    differences

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

    Failed Seal

    0.0

    0.2

    0.4

    0.6

    Abs

    Exemplar Seal

    -0.00

    0.02

    0.04

    0.06

    0.08

    0.10

    Abs

    Vespel SP-1 Polyimide

    0.02

    0.04

    0.06

    0.08

    0.10

    Abs

    800 1000 1000 1500 2000 3000 4000 Wavenumbers (cm-1)

    Exemplar Seal

    Latest Lot

    Vespel SP-1 Polyimide

  • FTIR in Failure Analysis The Madison Group 608-231-1907

    Scientific instruments were not performing well interference associated with light and UV radiation ingress

    Traced to production batch of covers

    Unreinforced pigmented grade of polycarbonate / poly(acrylonitrile:butadiene:styrene) (PC+ABS) blend

    Instrumentation Cover

    Jeffrey A. Jansen jeff@madisongroup.com

  • FTIR in Failure Analysis The Madison Group 608-231-1907

    Exemplar and failed covers produced results characteristic of PC+ABS

    Spectral variation in baseline below 800 cm-1 suggested formulation differences

    Instrumentation Cover

    Jeffrey A. Jansen jeff@madisongroup.com

    Exemplar Cover

    Failed Cover

    PC+ABS

  • FTIR in Failure Analysis The Madison Group 608-231-1907

    Exemplar and failed covers produced results characteristic of PC+ABS

    Spectral variation in baseline below 800 cm-1 suggested formulation differences

    More about this later.

    Instrumentation Cover

    Jeffrey A. Jansen jeff@madisongroup.com

    Exemplar Cover

    Failed Cover

    PC+ABS

  • Polyethylene Tubing Polyethylene tubing used in

    an ice maker supply line failed in service resulting in substantial water damage

    FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

  • Polyethylene Tubing Analysis of new tubing of

    same brand produced results characteristic of polyethylene

    Failed tubing produced from polyethylene

    Failed tubing outer diameter good match with new

    Failed tubing inner diameter - spectral bands associated with oxidation

    Tubing degraded from contact with chlorinated potable water

    More about this later FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

    Failed Tubing - Outer Diameter

    0.0

    0.1

    0.2

    0.3

    0.4

    Abs

    Failed Tubing - Inner Diameter

    0.1

    0.2

    0.3

    0.4

    Abs

    New Tubing

    0.0

    0.1

    0.2

    0.3

    0.4

    Abs

    800 1000 1000 1500 2000 3000 4000 Wavenumbers (cm-1)

    New Tubing

    Failed - ID

    Failed - OD

    1740

    1712

  • Motor Housing Motor housing produced

    from polycarbonate / poly(acrylonitrile:butadiene:styrene) (PC+ABS) blend failed in service

    Produced off-shore Failed during outdoor

    service at low temperature

    FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

  • Motor Housing FTIR analysis showed

    difference between parts used for first article submission and field failure resin substitution

    Both materials PC+ABS Field failure lower ABS

    content resin

    FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

    Failed Housing

    -0.00

    0.05

    0.10

    0.15

    0.20

    Abs

    First Article Submission

    -0.0

    0.1

    0.2

    0.3

    Abs

    PC+ABS

    -0.0

    0.1

    0.2

    0.3

    Abs

    800 1000 1000 1500 2000 3000 4000 Wavenumbers (cm-1)

    Failed Housing

    First Article Housing

    PC+ABS

    ACN

    BUT

  • Feeder Screw A plastic feeder screw

    cracked during use causing service interruption

    Material specified as poly(butlyene terephthalate) PBT with polytetrafluoroethylene (PTFE) additive

    It was suspected that molder had substituted a cheaper material

    FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

  • Retaining Clip

    Inserted components failed during assembly

    Cracking within snap fit retention arm

    Assembly with pneumatic equipment, but not automated

    Unfilled PBT

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

  • Retaining Clip

    Crack initiation at inclusion distinctly different morphology

    Inclusion acted as discontinuity concentrating stress applied during snap insertion

    Brittle fracture

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

  • Retaining Clip

    Inclusion identified as PPS

    More about this later.

    White Particle in Fracture Surface, Bowles Fluidics, TMG 13-11230-00, JN

    0.000

    0.005

    0.010

    0.015

    0.020

    0.025

    Abs

    White Particle in Fracture Surface - try 2, Bowles Fluidics, TMG 13-11230-00, JN

    0.00

    0.01

    0.02

    0.03

    Abs

    PPS, TMG Internal Library, JN

    0.1

    0.2

    0.3

    0.4

    Abs

    800 1000 1000 1500 2000 3000 4000 Wavenumbers (cm-1)

    Poly(phenylene sulfide)

    Inclusion 2

    Inclusion 1

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

  • Pump Body

    Pump bodies failed while in service

    Injection molded from poly(phenyl sulfone) (PPSU)

    Powdered metal retainer resin impregnated to seal

    Cracking within the bosses securing metal retainer to the body

    Residue within cracking

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

  • Pump Body

    Pump bodies failed while in service

    Injection molded from poly(phenyl sulfone) (PPSU)

    Cracking within the bosses securing metal retainer to the body

    Cracking initiating along interface with the metal retainer.

    Failure mode identified as environmental stress cracking (ESC) FTIR in Failure Analysis The Madison Group 608-231-1907

    Jeffrey A. Jansen jeff@madisongroup.com

  • Pump Body

    FTIR results showed pump body to be produced from PPSU

    No evidence of contamination or degradation

    FTIR in Failure Analysis The Madison Group 608-231-1907 Jeffrey A. Jansen

    jeff@madisongroup.com

    Failed Part - Base Material, GEA Farm Technologies, TMG 13-12596-00, JAJ

    0.1

    0.2

    0.3

    0.4

    0.5