In an effort to increase automotive fuel efficiency, the replacement of many traditionally metal components, such as power train systems, with high specific modulus and specific toughness thermoplastics is of great interest. A glass reinforced polyamide 6/6 of interest was investigated by a 2^3 factorial designed experiment, using factors relevant to the materials industrial application, including operation temperature, strain exposure, and strongly reducing cleaner exposure, with characterization by tensile testing. The primary statistically significant effects were due to elevated operational temperature exposure, displaying an increase of 40% in tensile modulus alongside an 80% reduction in tensile elongation at break, likely due to cold crystallization of the polymer. Such a reduction in elongation at break may provide challenging, as often a visually deformed part signals the requirement for replacement, as opposed to failure while in use.

1. 1
PresentationPresentation to PACCARPACCAR
Analysis of Paccar Materials
Zytel, 2000EZ and TPO
11/14/14
Andrew Hollcraft, Louisa McCuskey & Kyle Burns
WWU - AMSECWWU - AMSEC

2. 2
IntroductionIntroduction
• Zytel 70GF33 HSLZytel 70GF33 HSL
– High Performance PolyamideHigh Performance Polyamide
Resin:Resin: PA 6/6, 33% Glass Filled
– Replaces many metal powertrainReplaces many metal powertrain
componentscomponents
– Praised for it’s stiffness and heatPraised for it’s stiffness and heat
resistanceresistance
– Capable of working in placesCapable of working in places
that may be too hot, humid orthat may be too hot, humid or
chemically aggressive forchemically aggressive for
traditional nylons.traditional nylons.

3. 3
Project DefinitionProject Definition
• Business ReasonBusiness Reason
• Testing materials prior to manufacturing will help ensureTesting materials prior to manufacturing will help ensure
the longest life and greatest durability of parts made fromthe longest life and greatest durability of parts made from
these materials.these materials.
• PurposePurpose
• To complete a full MSA to qualify our experimentalTo complete a full MSA to qualify our experimental
procedure, and a DOE report on Zytel 70GF33procedure, and a DOE report on Zytel 70GF33
• ScopeScope
• Investigation of mechanical properties as functions ofInvestigation of mechanical properties as functions of
temperature, strain and solvent exposure.temperature, strain and solvent exposure.

4. 4
Team
• Leaders
• Professor:: Dr. Rider
• Lab Supervisors:
• Jaime Campo
• Sam Dansforth
• Mentors
• PACCAR Support:
• Jordan Kiesser
• Kirk Dunn
• Team Members
• Andrew Hollcraft, Engineering
• Kyle Burns, Chemistry
• Louisa McCuskey, Physics
• Other Support
• Department: Chemistry
• Department: Engineering

5. 5
MSAMSA
• Material:Material:
Zytel 70GF33 HSL, Pulse 2000EZ, and TPO FT3250Zytel 70GF33 HSL, Pulse 2000EZ, and TPO FT3250
• Test Method(s):Test Method(s):
• Tensile testTensile test
• Gauge R&R (crossed)Gauge R&R (crossed)
• OperatorsOperators
• Operator 1 Kyle BurnsOperator 1 Kyle Burns
• Operator 2 Louisa McCuskeyOperator 2 Louisa McCuskey
• Operator 3 Andrew HollcraftOperator 3 Andrew Hollcraft

6. MSA Gauge R&R StudiesMSA Gauge R&R Studies
6
Tensile ModulusTensile Modulus
Ultimate Tensile StrengthUltimate Tensile Strength

7. MSA Gauge R&R StudiesMSA Gauge R&R Studies
7
Elongation at BreakElongation at Break
Elongation at YieldElongation at Yield

8. 8
Is the Data Trustworthy?Is the Data Trustworthy?
• Measurement System EvaluationMeasurement System Evaluation
• Results of EvaluationResults of Evaluation
– Operator 2 methodically consistent – flat slope on operator R chart.Operator 2 methodically consistent – flat slope on operator R chart.
– Modulus and Peak Stress had Gauge R&R values under 30%Modulus and Peak Stress had Gauge R&R values under 30%
– Strain at Break and % Elongation at Yield were both over 30% gaugeStrain at Break and % Elongation at Yield were both over 30% gauge
R&RR&R
• Corrective ActionsCorrective Actions
– Elongation at Yield was estimated due to inaccurate softwareElongation at Yield was estimated due to inaccurate software
calculations.calculations.
• Algorithm / computer generated method.Algorithm / computer generated method.
– Elongation at Break could be inaccurate due to slipping, whichElongation at Break could be inaccurate due to slipping, which
occurred 4 times.occurred 4 times.
• Revise gripping procedureRevise gripping procedure
– TabsTabs

9. 9
DOEDOE
• Material Tested:Material Tested:
Dupont Zytel 70GF33 HSL , Polyamide 6/6 33% Glass FilledDupont Zytel 70GF33 HSL , Polyamide 6/6 33% Glass Filled
• Test Method(s):Test Method(s): Tensile testTensile test
• Experimental Design:Experimental Design: 3 factors with 2 levels = 23
factorial
design. Total of 8 runs, with 3 replicates total of 24 runs.
• Factors and Factor LevelsFactors and Factor Levels::
Temperature (23°C and 85°C)Temperature (23°C and 85°C)
Strain Exposure (No or Yes)Strain Exposure (No or Yes)
Solvent Exposure* (No or Yes)Solvent Exposure* (No or Yes)
*concrete cleaner with muriatic acid*concrete cleaner with muriatic acid
• Response (s):Response (s): Ultimate Tensile Strength, Tensile Modulus,Ultimate Tensile Strength, Tensile Modulus,
Strain at Yield, and Strain at BreakStrain at Yield, and Strain at Break

10. Regression Result Ultimate Tensile
Strength (Δ%)
Tensile Modulus
(Δ%)
ElongationYield (Δ
%)
ElongationBreak (Δ
%)
Model Adjusted R2
0.652 0.785 0.687 0.931
A: Solvent
Exposure
- - - -
B: Temperature 17.6 36.3 -11.7 -77.5
C: Prestrain - - 9.28 -
AB -7.97 - -6.23 -
AC - - - -
BC - - 7.62 -
ABC - - 7.71 -
10
DOE ResultsDOE Results

11. 11
DOE Analysis SummaryDOE Analysis Summary
• ObservationsObservations
– Tensile modulus and ultimate tensile strength bothTensile modulus and ultimate tensile strength both
increased with increased temperatureincreased with increased temperature
• Polyamide 6/6 is known for heat resistance and stiffnessPolyamide 6/6 is known for heat resistance and stiffness
• AnnealingAnnealing
– Elongation at yield and break both decreased withElongation at yield and break both decreased with
increased temperatureincreased temperature
• Imparting thermal stress into the sampleImparting thermal stress into the sample
• Higher crystallinity sampleHigher crystallinity sample

12. DOE Analysis SummaryDOE Analysis Summary
12
• Increased temperature is the mainIncreased temperature is the main
concernconcern
– Solvent exposure further increases theSolvent exposure further increases the
temperature effect magnitudetemperature effect magnitude
– Solvent exposed samples tended toSolvent exposed samples tended to
fracture at the interface of solvent andfracture at the interface of solvent and
non solvent exposed materialnon solvent exposed material

13. 13
Project Results – Key TakeawaysProject Results – Key Takeaways
• Additional operator practice and process revision isAdditional operator practice and process revision is
necessary to reduce external errornecessary to reduce external error
• Elevated temperatures appears to have a negativeElevated temperatures appears to have a negative
statistically relevant effect for Elongation at Yieldstatistically relevant effect for Elongation at Yield
and Breakand Break
– Increases Ultimate Tensile Strength and Tensile ModulusIncreases Ultimate Tensile Strength and Tensile Modulus
• AnnealingAnnealing
– Additional testing under increased time frames may beAdditional testing under increased time frames may be
beneficialbeneficial
– Solvent and temperature interaction may also play a role,Solvent and temperature interaction may also play a role,
but statistical significance was not observedbut statistical significance was not observed

14. 14
Lessons LearnedLessons Learned
• Lessons LearnedLessons Learned
– Measurement systems analysis are a valuable tool toMeasurement systems analysis are a valuable tool to
evaluate how robust a method isevaluate how robust a method is
– Designed experiments allow for straightforwardDesigned experiments allow for straightforward
evaluation of test resultsevaluation of test results

15. Questions?Questions?
15

16. AppendixAppendix
16

17. Ultimate Tensile StrengthUltimate Tensile Strength
17

18. Tensile ModulusTensile Modulus
18

19. Strain at YieldStrain at Yield
19

20. Strain at BreakStrain at Break
20

21. DiscolorationDiscoloration
21
Low heat, no solvent;
low heat, solvent;
high heat and solvent