MPG 2016

Bespoke compound

engineering for elastomers engineering for elastomers

used in extreme environments

Clwyd Compounders Ltd.

Introduction

• Challenging service conditions and engineering specifications are now

more prevalent

• Analysis of processing and service requirements plus innovative

compounding gives the best chance of success

• We will showcase some compounds designed for extreme service • We will showcase some compounds designed for extreme service

conditions

• look at tested properties and performance in ED tests

• Discuss difficulties facing compounders today as tougher requirements call

for engineering solutions.

• Also discuss a novel sealing solution and the associated rubber technology

• Component service conditions are becoming increasingly challenging

particularly in oil & gas industry

• Exposure to CH4, CO2, steam and sour conditions (H2S) at high

temperature and pressure

• Material which passes engineering specification and industry-standard

Developing compounds for enhanced oil

recovery

• Material which passes engineering specification and industry-standard

explosive decompression (ED) testing may be difficult to mould,

leading to defects in finished components

• Screening experiments on a range of compound types produced by

Clwyd Compounders, which included:

• HNBR

• Aflas (TFE/P)

• various subtypes of FKM

• FFKM

Screening experiments : compounds for

enhanced oil recovery

• Tested steam resistance, resistance to sour conditions (H2S) and rapid

gas decompression (RGD) resistance

Test

medium

Pressure

(bar)

Temperature (ºC) Test type

CO2 350 100 RGD (1 cycle) using 312 O-rings

Steam 150 220 2wks ageing, then tensile testing

65% H2S/

35% CO2

20 150 2wks ageing, then tensile testing

• Viton ETP 90, Aflas 90 and High fluorine FKM (type 2) compounds gave

best results for chemical resistance against steam and sour conditions

• Best results for RGD resistance were obtained from a compound

containing a specific specialist filler system

• Formulations were further refined by using a specialist filler system in

Screening test results: compounds for

enhanced oil recovery

• Formulations were further refined by using a specialist filler system in

revised versions of chemically resistant compounds

Material description Comments

Aflas 90 Designed for ED resistance, good steam and H2S

resistance

FKM High Fluorine 90 Designed for non-sour environment at high

temperatures and improved ED resistance

ETP 90 Designed for good ED resistance, steam and H2S

resistance at high temperatures

Aflas 80 Designed for ED resistance, good steam and H2S

resistance with high E@B

Test results on refined compounds

Aflas 90FKM High

Fluorine 90ETP 90 Aflas 80

Hardness (IRHD) 94 91 91 81

TS (MPa) 22.2 25.4 25.0 20.1

E @ B (%) 108 167 124 244

Mod @ 50% (MPa) 11.3 7.2 8.6 4.6

Mod @ 100% (MPa) 21.2 14.6 20.0 10.4

Tear strength (N/mm) 41 40.4 35 36

Compression set (%)

22 h at 200 ºC11 14 35 34

Heat Age Resistance

70 h at 200 ºC

Hardness Change (IRHD) +6 +8 +1 +5

Tensile Strength Change (%) -1 -25 -5 -3

E @ B Change (%) -3 -20 -12 +4

Aflas 90

FKM High Fluorine 90

ETP 90

Aflas 80

0.00 0.25 0.50 0.75

1.50

3.00

4.50

6.00

7.50

9.00

10.50

0.00 0.25 0.50 0.75

1.50

3.00

4.50

6.00

7.50

9.00

10.50

0.00 0.25 0.50 0.75

1.50

3.00

4.50

6.00

7.50

9.00

10.50

0.00 0.25 0.50 0.75

1.50

3.00

4.50

6.00

7.50

9.00

10.50

Rheology at 185°C on refined compounds

ML (dNm)

Aflas 90 4.76

FKM 90 4.34

ETP 90 3.46

Aflas 80 4.06

Test results on refined compounds

TS change (%) E @ B change (%) Mod @ 50% change (%)

Aflas 90 < -25 < -25 < +25

FKM High

Fluorine 90> -50 > -50 > -50

ETP 90 < -25 < -25 < -25

After steam exposure (220ºC and 150 bar for 2 weeks)

The following properties were independently tested at a recognised

test house:

TS change (%) E @ B change (%) Mod @ 50% change (%)

Aflas 90 < +19 < -19 < +19

FKM High

Fluorine 90< +19 < -19 < +19

ETP 90 < +19 < -19 < +19

Aflas 80 < +19 < -19 < +19

After exposure to sour conditions (150ºC and 20 bar for 2 weeks )

ETP 90 < -25 < -25 < -25

Aflas 80 < +25 < +25 < +25

Test results on refined compounds

TS change (%) E @ B change (%) Mod @ 50% change (%)

Aflas 90 Not tested Not tested Not tested

FKM High

Fluorine 90Not tested Not tested Not tested

After exposure to hydrocarbons (NORSOK oil test 7 days at 150ºC),

followed by exposure to steam (220ºC and 150 bar)

The following properties were independently tested at a recognised

test house:

NORSOK RATING

Aflas 90 FAIL

FKM High

Fluorine 90PASS

ETP 90 FAIL

Aflas 80 PASS

RGD resistance testing

Fluorine 90

ETP 90 -25 to -50 < +25 +25 to +50

Aflas 80 < -25 < +25 -25 to -50

Aflas 90 Failure FKM 90 Pass

• Tested refined compounds for resistance to sour gas, steam and RGD

• Best all-round performance was seen from Aflas 80 compound

• Aflas 80 performed well in steam, even at higher temperatures (250°C

and 265°C) and showed good resistance to sour conditions

• 312 O-rings passed RGD testing

Conclusions on refined compounds

• 312 O-rings passed RGD testing

• Moved on to moulding trials

• Compression moulding did not produce a good quality part

• Transfer moulding gave good quality parts free from moulding flaws when

examined along the cross-section

Example of compression moulded packer

showing splits from poor consolidation

Example of transfer moulded packer free

from moulding defects

ED Testing on Clwyd Compounds

• Validated some designed compounds against the rigorous requirements of

the Norsok M710 speciation

• next step was to expand the product range

• CCL have portfolio of materials for use in these environments

• Validated the formulation design and gained better understanding of the • Validated the formulation design and gained better understanding of the

requirements

• design compounds tailored for individual processes that will meet

the specifications and service conditions

• offer impartial choice on suitable grades for best processing and

performance

Test results on Clwyd ED resistant compounds

FFKM Aflas FKM Type 1 FKM Type 2 HNBR

Hardness IRHD 94 90 91 90 86

Specific Gravity g/cm3 1.93 1.58 1.87 1.71 1.15

• We designed further ED resistant compounds using different base

elastomers and tested basic physical properties internally

Specific Gravity g/cm3 1.93 1.58 1.87 1.71 1.15

Tensile Strength MPa 23.4 17.3 17.9 17.8 25

Elongation to

Break% 101 107 215 116 419

Modulus @ 100% MPa 23.4 16.6 10.0 15.8 7.1

Compression set %

72 hours

@ 200°C

22 hours

@ 200°C

22 hours @

200°C

22 hours @

200°C

24 hours

@ 150°C

24 20 15 13 39

Rapid gas decompression testing ISO 23936-2

Test piece and fill factor312 O ring size at 85% fill factor

Test results on Clwyd ED resistant compounds

• We designed further ED resistant compounds using different base

elastomers and tested ED resistance in accordance with ISO 23936-2

Gas mixture10/90 CO2/CH4

FFKM Aflas FKM Type 1 FKM Type 2 HNBR

Rating 0000 0000 0000 0000 0000

Designing Compounds for non-standard ED

Resistant Parts

• Sometimes other parts than

o-rings are required for

these extreme environments

which may need similar ED

resistance, such as packers

• Elastomers are often used in critical applications, need to understand

engineering requirements

• Design engineers are designing parts for purpose which may need

evaluating in service conditions

• When testing to N710 and chemical testing good information is

ascertained – but actual parts may not reflect this test performance

• Global catastrophes have emphasized the need for rigorous testing

• Test methods are for o-rings - in service testing is paramount

• Cooperation between compounder, design engineer and component

manufacturer – feedback is key in order to adapt and refine

• There is a huge diversity of materials within the sector

Designing Compounds for non-standard Parts

• There is a huge diversity of materials within the sector

• FKM and HNBR are generalisations that are often asked for

• there are many grades available offering a wide range of chemical

and physical resistances

• FKM grades available for extremes of high or low temperature (-

45°C) with high chemical resistance

• need to understand service requirements for correct selection

Best

Formulation Design

High

Designing Compounds for non-standard Parts

Best Chance of

Success

High Compound

Quality

Processing Considerations

Correct Grade Selection

Challenging Conventions - Water Swellable

Compounds

• Rubber very often required to resist the ingress of fluids for sealing

applications - elastomers are selected for low swell in fluids

• Some applications require this concept to be turned on its head

• Water swellable compounds can provide an inexpensive seal against

ground water down bore holesground water down bore holes

• The function is still to stop fluids but by a different mechanism

• Elastomer seals overcome the shortcomings in engineered contact points

• Large engineering projects require elastomer seals more than ever

• less precise materials such as concrete tunnel segments

• Where the sealing faces cannot be mapped such as rough cut bore holes

the function of a swellable elastomer is vital

Challenging Conventions - Water Swellable

Compounds

the function of a swellable elastomer is vital

• Conditions can range from ambient low pressure areas to high pressure

high temperature scenarios requiring swell sealing up to 600°F

• These are very extreme conditions and present problems for the swell

medium and the elastomer itself.

Elastomeric gaskets make up one of the most effective systems for

segmentally lined tunnels where sealing is required against water ingress, or

for retention in tunnels used for fluid transport or storage.

The complex section of the gaskets is designed to provide the energy within

the seal, generating the sealing function once the segments have been

assembled, whilst minimising closure forces.

Water Swellable Components

http://www.vip-polymers.com/products-item/tsg-information/

Water Swellable Compounds

An example of a water swell

graph for a conventional

swelling NBR compound

An example of a water

swell graph for a

conventional swelling PCR

compound

• Conventional water swell proceeds by an osmotic mechanism

• Ions are replaced by water molecules by osmotic pressure which expands

the polymer matrix

• In high temperatures conventional mechanisms will not survive

• Certain ceramics can absorb water into interstices to expand up to 100%

Water Swellable Compounds

• Certain ceramics can absorb water into interstices to expand up to 100%

• Engineering on the part minimises distance until swell sealing is achieved

• Certain elastomers inherently offer high resistance to steam including

FFKM, Aflas (TFE/P) and to a degree EPDM

• Further enhancements can be made to steam resistance of the base

elastomers by special compounding techniques

http://www.tmt.unze.ba/zbornik/TMT2012Journal/13.pdf

Water Swellable Components

An example of a conventional water

swellable packer

https://www.youtube.com/watch?v=j3HX5Ai-vfE

An example of a

higher

temperature and

pressure

swellable packer

Conclusions

• Knowledge of compounding techniques to design materials suitable for

extreme conditions is required

• Materials then need independent testing to check suitability in function

• Standardised tests, such as Norsok, are widely recognised and give a degree

of confidence in the compound/parts capability

• However these tests are not always associated with the parts performance

• With such a wide variety of parts, environments , service and chemical

conditions in-situ test data is more relevant to performance

• Feedback is essential for compounder to fulfil the service requirements

• can be used to adapt and refine compounds further for optimum

performance in extreme environments

• By use of innovative technology and novel ingredients we can find solutions

to even the most demanding and extreme applications

Thank you for your time

Clwyd Compounders Ltd.,

Gardden Industrial Estate,

Ruabon,

Wrexham,

LL14 6RG

t: +44 (0)1978 810 551

e: sales@clwydcompounders.com

www.clwydcompounders.com