Low temperature propertiesp p pStandard methods and sealability of O-rings

Martin BellanderSara WengströmSGF Conference, Malmö

10-11 April 2013Diploma Work

KTH, Stockholm20122012

Agenda

Background MaterialsMaterials Methods Results Results Conclusions

F t O tl k Future Outlook

Background

28 januari 1986

Background Function, i.e. sealing at -40°C

S li h k d Sealing when parked Cold start Dynamic seal Static seal Fluids become viscous Consequence if leakage q g

occur

Materials101

84

86

88

90

92

94

96

98

100

%T 1069,33cm-1

1397,38cm-1

888,76cm-1

1694,1

1736,6 1456,4

1429,7

1352 833,96

819,83

767

723,92

682,2

6770077_interactive baselineName Description

4000 6503500 3000 2500 2000 1500 100074

76

78

80

82

84

cm-1

1179,79cm-1

Mtrl IRHD

34% ACN, ca 5% softener 68

Mtrl IRHD

AEM HVG ca 10 parts oil 72

19% ACN, ca 10% softener 63

low T compound 73

AEM GLS ca 20 parts oil 77

AEM HVG ca 20 parts oil 36

34% ACN 70

21% ACN, ca 10% softener 70

AEM HVG/GLS ca 15 parts oil 50

FKM copolymer 74

FKM GFLT 76FKM GFLT 76

FKM terpolymer 73

FKM GBLS 70

MethodsDMADSC DSC - Differential Scanning

CalorimetryM h t fl h i h t itMeasure heat flow, change in heat capacity

DMA - Dynamic Mechanical AnalysisMeasure force and displacment dynamically

Single cantilever 1 Hz 5°C/min 0 5% strain

TR

Single cantilever, 1 Hz, 5°C/min, 0.5% strainamplitude

TR - Low Temperature RetractionSample strained 50%, cooled down below freezing.

GehmanTRSample strained 50%, cooled down below freezing. Percentage recovery measured when temperatureis increased

Low Temperature Stiffening –G hGehmanSimilar to TR, but torsional measurement

at different temperaturesO i l bilit i ll

TR10 TR70

O-ring sealability, speciallydesigned test rig

TR10 TR70

O-ring sealability test

Special test rigFillingPressure

Placed in a cold chamber O-rings 140x3,4 mm Cooling in steps 2-5°CTest O-ring Cooling in steps 2 5 C Cooling without pressure Pressure 3 bar when

temperature equilibrium for 30

Test O ring

temperature equilibrium, for 30 min to detect leakage.

When leakage: temperature i d t RT th l d d

Coolant

raised to RT, then cooled down to Tleakage + 1°C to check leakageT T 1°C Tsealing = Tleakage + 1°C

O-ring sealability test

Example of leakageTest rig in cold chamber

Results: Tg by DSC

MtrlTg

(DSC)

NBR 34% 34

MtrlTg

(DSC)

AEM HVG ca 10 parts oil 36NBR 34% -34

NBR 19% -60

NBR low temp -44

AEM HVG ca 10 parts oil -36

AEM GLS ca 20 parts oil -35

AEM HVG ca 20 parts oil -42p

HNBR 34% -20

HNBR 21% -36

AEM HVG/GLS ca 15 parts oil -38

FKM copolymer -15

FKM GFLT -23

FKM terpolymer -11

FKM GBLS 15FKM GBLS -15

Results: Tg by DMA

Tg E´´ Tg Tan Tg E´´ Tg Tan Mtrl

Tg E(DMA)

Tg Tan (DMA)

NBR 34% -27 -24

MtrlTg E(DMA)

Tg Tan (DMA)

AEM HVG ca 10 parts oil -31 -27

NBR 19% -51 -44

NBR low temp -37 -33

HNBR 34% 23 20

AEM GLS ca 20 parts oil -30 -25

AEM HVG ca 20 parts oil -34 -30

AEM HVG/GLS ca 15 parts oil 31 27HNBR 34% -23 -20

HNBR 21% -35 -30

AEM HVG/GLS ca 15 parts oil -31 -27

FKM copolymer -10 -3

FKM GFLT -25 -21

FKM terpolymer -11 -5

FKM GBLS -14 -10

Results: TR10

TR10 TR10 TR10 TR10 TR10 TR10Mtrl Scania Trelleborg Elastocon

NBR 34% -30 -29 -30

NBR 19% -51 -51 -52

Mtrl Scania Trelleborg Elastocon

AEM HVG ca 10 parts oil -29 -31 -31

AEM GLS ca 20 parts oil 30 31 32NBR 19% -51 -51 -52

NBR low temp -43 -41 -43

HNBR 34% -20 -18 -20

AEM GLS ca 20 parts oil -30 -31 -32

AEM HVG ca 20 parts oil -38 -39 -39

AEM HVG/GLS ca 15 parts oil -35 -34 -35

HNBR 21% -35 -32 -36

p

FKM copolymer -16 -16 -16

FKM GFLT -25 -24 -25

FKM terpolymer -13 -13 -13

FKM GBLS -17 -17 -17

Results: TR10

B h i Behaviour per polymer/monomer type

AEM

type

NBR and HNBR

FKM

Results: Gehman

Mtrl T2 T10 T50 T70 T100 T2 T10 T50 T70 T100

NBR 34% AEM HVG ca 10 parts oil -17 -34 -39 -40 -42

NBR 19% AEM GLS ca 20 parts oilNBR 19% AEM GLS ca 20 parts oil

NBR low temp AEM HVG ca 20 parts oil -24 -40 -44 -50 -46

HNBR 34% -20 -24 -29 -31 -33 AEM HVG/GLS ca 15 parts oil -23 -37 -41 -42 -43

HNBR 21% -31 -38 -43 -44 -46 FKM copolymer -7 -15 -20 -21 -22

FKM GFLT -20 -25 -29 -30 -33

FKM terpolymer -7 -13 -17 -19 -22

FKM GBLS -12 -17 -21 -23 -25

Results: TR10 vs Tg (DSC)

0 NBR 34%

‐10

‐70 ‐60 ‐50 ‐40 ‐30 ‐20 ‐10 0NBR 34%NBR 19%NBR low tempHNBR 34%

‐30

‐20

R10

HNBR 34%HNBR 21%AEM HVG ca 10 parts oilAEM GLS ca 20 parts oil

y = 0,7832x - 4,4478R² = 0,9681

‐40

T AEM GLS ca 20 parts oilAEM HVG ca 20 parts oilAEM HVG/GLS ca 15 parts oilFKMcopolymer

‐60

‐50FKM copolymerFKM GFLTFKM terpolymerFKMGBLS60

Tg (DSC) FKM GBLS

Results: TR10 vs Tg (DMA tan)

0

‐10

0‐50 ‐40 ‐30 ‐20 ‐10 0

NBR 34%NBR 19%NBR low tempy = 0,9352x - 7,7903

R² 0 9137

‐30

‐20

R10

HNBR 34%HNBR 21%AEM HVG ca 10 parts oil

R² = 0,9137

‐40

30

TR AEM GLS ca 20 parts oilAEM HVG ca 20 parts oilAEM HVG/GLS ca 15 parts oilFKM l

‐60

‐50

( )

FKM copolymerFKM GFLTFKM terpolymerFKMGBLSTg (DMA tan) FKM GBLS

Results: O-ring sealability, Tsealing

M l TMtrl Tsealing

NBR 34%

NBR 19% -54*

Mtrl Tsealing

AEM HVG ca 10 parts oil -51

AEM GLS ca 20 parts oil -52NBR 19% -54

NBR low temp

HNBR 34% -32

AEM GLS ca 20 parts oil 52

AEM HVG ca 20 parts oil

AEM HVG/GLS ca 15 parts oil

HNBR 21% -50 FKM copolymer -31

FKM GFLT -48

FKM terpolymer

FKM GBLS -34

* Did not leak at all before coolant become frozen

Sealability vs Standard Test Methods

Sealability vs Tg (DSC)

0

‐10

0‐70 ‐60 ‐50 ‐40 ‐30 ‐20 ‐10 0 NBR 19%

HNBR 34%

‐30

‐20

ealing

HNBR 21%

AEM HVG ca 10 parts oily = 0,9002x - 19,357R² = 0 8042

‐40

30

T se

AEM GLS ca 20 parts oil

FKM copolymer

R = 0,8042

‐60

‐50

( )

FKM GFLT

FKM GBLSTg (DSC)

Sealability vs Tg (DMA, tan)

0

‐10

0‐50 ‐40 ‐30 ‐20 ‐10 0 NBR 19%

HNBR 34%

‐30

‐20

ealing

HNBR 21%

AEM HVG ca 10 parts oil

y = 0,85x - 26,134R² = 0,6998

‐40

30

T se

AEM GLS ca 20 parts oil

FKM copolymer

‐60

‐50

T (DMA )

FKM GFLT

FKM GBLSTg (DMA tan)

Sealability vs TR10

0

‐10

0‐60 ‐50 ‐40 ‐30 ‐20 ‐10 0 NBR 19%

HNBR 34%

‐30

‐20

aling

HNBR 21%

AEM HVG ca 10 parts oil

y = 1,2123x - 13,016R² = 0,8075

‐40

30

T se

AEM GLS ca 20 parts oil

FKM copolymer

‐60

‐50FKM GFLT

FKM GBLSTR10

Sealability vs T10 (Gehman)

0

‐10

0‐40 ‐35 ‐30 ‐25 ‐20 ‐15 ‐10 ‐5 0 HNBR 34%

HNBR 21%y = 0 9012x - 18 124

‐30

‐20

sealing

HNBR 21%

AEM HVG ca 10 parts oil

y 0,9012x 18,124R² = 0,7138

‐40

T s

FKM copolymer

FKMGFLT

‐60

‐50

Gehman T10

FKM GFLT

FKM GBLS

Conclusions

Standard methods investigated correlate well with eachStandard methods investigated correlate well with each other

O i ( t ti ) l t t t ll b l O-ring (static) seals to temperatures well below temperatures indicated by standard methods

Tsealing does not correlate with standard test methods in a general behaviour over all polymer types

Prediction of Tsealing seems to be possible to make within a series of the same polymer type

Future Outlook

Temperatures are still increasing in automotive applicationspp

High temperature resistance often at the expense of low temperature propertieslow temperature properties

Low temperature properties will become moreLow temperature properties will become more important

Need to specify the right low temperature properties

Thanks to:

Trelleborg Ersmark AB Trelleborg Ersmark AB for supplying material and test resultsEl t AB Elastocon AB for using their instrumentsS W t ö Sara Wengströmfor performing the diploma work

Thanks for your attention!