Wind Turbine Rotor Blades , June 23-24, 2015, Haus der Technik, Essen, Germany

Influence of Glass Fibre Sizing and Storage Conditions onComposites Properties

Luc Peters and the 3B team

� 3B-the fibreglass company

� How glass fibre is produced

� How sizings work

� Sizing ageing study

- Rovings

- Fabrics drying

� Conclusions

content

a reference in fibreglass… innovative, entrepreneur and eco-enthusiast

Advantex® is a registered trademark of Owens Corning used under license.

� 3B is part of The Braj Binani Group which is a conglomerate with diversified interests in cement, zinc, glass fibre and composites

Major and dynamic actor in composite reinforcement solutions

� A special focus on thermoplastics, wind energy, performance composites

� 1000 experts building upon a long heritage of 45 years of expertise

� 160 000 tons of glass produced per year

� Innovating and setting new standards within the fibreglass industry based on our two unique high performance and eco-responsible glass technologies: Advantex ® glass and HiPer-tex™

unique glassfibre solutionshigh performance and eco-responsible

…with global presence

� Sales Offices� Europe

� Bruxelles� India� China

� Productions� Birkeland, Norway� Battice, Belgium� Goa, India

� Research & Application Development� Battice, Belgium (Lüttich, 25 km from Aachen)� Activities in Glass – Fibre coating – Composite

to most effectively serve our partners

Chopper

WUCS(Wet Used Chopped Strand)

3

3B glass fibre processes

Winder

Furnace(melting)

Batch House(dosing/mixing)

Glass Raw Materials

Oven(drying-curing)

FORMING = Bushings(fiberizing)

1

23

Sizing(coating )

DR (Direct roving)

1

Fluid Bed Oven(drying-curing-cooling)

Screen

CS(Chopped Strand)

4

Granulator

Oven(drying-curing)

CFM(Continuous Filament Mat)

2

Note : Multi end roving and Chopped Strand Mat from Goa plant not represented here

how sizings (or sizes) work

Size is applied as a water based formulation,

it contains:

� Coupling agent(s) : Provides adhesion between glass surface and the

resin => Silanes, ….

� Film Former(s) : Provides protection and strand integrity to the roving

as well as compatibility with the resin => EP, PU, VE, …

� Lubricant(s) : Provides lubrication and protects the filaments during

processing

� Other Additives : antistat, emulsifier, anti foaming, bactericide, ...

SizingFunction

Role of GF sizing = ensure good transfer of load applied on the composite from the polymer matrix to the glass.

GF sizing are specific to polymer matrix and final application

PA66 - 50%wt GF Poor coating Good coatingTensile strength (MPa) 50 180Notched Impact Strength (kJ/m2) < 5 18

Poor sizing Good sizing

SizingSilane condensation on the glass surface

9

• Function = coupling glass (inorganic) to other sizing ingredients and polymer matrix (organic)

• Chemical nature = functionalized silane

Condensation of methacryloxysilane on glass surface ⇒ covalent bond !!!

Si

O

O

O

H

H

H

CH2 CH2 CH2 O C C

CH3

CH2

O

SiH3 OH +

Si

O

O

O

H

SiH3

H

CH2 CH2 CH2 O C C

CH3

CH2

O

+ H2O

Glass

Si

Si

+ H2O

T°, - H2O

!! Reversible reaction

SizingTypes of Silanes used in thermoset sizings

10

− γ -aminopropyltriethoxysilane � Epoxy resin

− γ-methacryloxypropyltrimethoxysilane � VE and UPE

Si

O

O

O

CH3

CH3

CH3

CH2 CH2 CH2 O C C

CH3

CH2

O

Si

O

O

O

CH2

CH2

CH2

CH2 CH2 CH2

CH3

CH3

CH3

NH2

Sizing

11

− γ-glycidoxypropyltrimethoxysilane � Epoxy resin

Si

O

O

O

CH3

CH3

CH3

CH2 CH2 CH2 O CH2 C CH2

O

H Glycidoxy = Epoxy

Types of Silanes used in thermoset sizings

SizingSilane

12

Stability of silane in water related to hydrolysis – condensation equilibrium

• Silane is hydrolysed in water during sizing preparation ⇒ formation of silanolbonds

• Hydrolysed silane tends to condensate with time and to form silane oligomers

� Solubility � and gel formation ⇒ reduction of sizing stability

� Silane oligomers will not properly cover/react at glass surface ⇒ reduction of composite mechanical properties

Silane Hydrolysis

13

Ageing of composites and sizingin presence of water => loweradhesionReversible reaction ! Main factors: temperature, H20,

Product & Size Ageing: Coupling Agent(s)

14

� Coupling agents:� Amino:

�continue to crosslink and to react with film former � reduced solubility, less wetting by the matrix.

� Methacryl : �when inhibitor is consumed, then can homopolymerise or crosslink if

unsaturated polyester film former �reduce speed of dissolution or solubility in the matrix,.

� Epoxy: �Could progressively react with amine or acid if present� reduced

solubility�Epoxy functionality can be progressively hydrolysed� reduced

reactivity

Sizing ageing and rovings storageconditions impact on mechanicalproperties

Laminate construction (with one roving)

-Dry winding of flat panel: - 4x 845gr/m² = 3380 gr/m2 (4 layers UD roving) at 0°=> laminate of 2 mm

-Infusion in Epoxy resin Hexion RIMR 135/137 at 35°c, full vacuum, 4 products/infusion in most cases4 hours at 90° post-cure

Testing- Tensile at 90 °- Short beam test according ISO 14130.- Glass contents by weight range 72 to 75.5 %

Typical set up of infusion of 4 products in one shot

Products & Conditionning

17

� Pallets from Birkeland plant (rovings have different starting « age » )

- Reference sizing (SE1500) 17-2400 production date : 4/3/2013- New sizing (SE2020) 17-2400 production date : 11/4/2012- New Multi Compatible sizing (W3030)17-2400 production date : 5/9/2013

� Static test before conditioning� Trip to/from Dubai for SE1500 & SE2020 from August to December

� 1 week at -18°C (check Epoxy crystallisation)� 2.5 months in oven at 50OC in Lab (RH=2-3%)

� 2.5 + 2.5 months at 30°/80%RH (21,5 gr H2O / Kg air) � 2.5 +2.5 months at 30°/80%RH in 2 PE bags sealed

Note: 2020 sizing is epoxy specific and 3030 sizing is multi resins (UP, VE, EP) compatibleSE means the sizing is applied on Advantex glass, W means it is applied on HiPer-tex glass

Conditionning room & bobbins

18

BobbinsBobbins insealed PE bags

T°

& R

H in the pallets

which

wentto and back from

Dubai

19

0 10

20

30

40

50

60

70

80

90

0 5

10

15

20

25

30

35

40

45

8/06/2013 8:28

8/08/2013 17:28

8/11/2013 2:28

13/08/2013 11:28:28

15/08/2013 20:28:28

18/08/2013 05:28:28

20/08/2013 14:28:28

22/08/2013 23:28:28

25/08/2013 08:28:28

27/08/2013 17:28:28

30/08/2013 02:28:28

9/01/2013 11:28

9/03/2013 20:28

9/06/2013 5:28

9/08/2013 14:28

9/10/2013 23:28

13/09/2013 08:28:28

15/09/2013 17:28:28

18/09/2013 02:28:28

20/09/2013 11:28:28

22/09/2013 20:28:28

25/09/2013 05:28:28

27/09/2013 14:28:28

29/09/2013 23:28:28

10/02/2013 8:28

10/04/2013 17:28

10/07/2013 2:28

10/09/2013 11:28

10/11/2013 20:28

14/10/2013 05:28:28

16/10/2013 14:28:28

18/10/2013 23:28:28

21/10/2013 08:28:28

23/10/2013 17:28:28

26/10/2013 02:28:28

28/10/2013 11:28:28

30/10/2013 20:28:28

11/02/2013 5:28

11/04/2013 14:28

11/06/2013 23:28

11/09/2013 8:28

11/11/2013 17:28

14/11/2013 02:28:28

16/11/2013 11:28:28

18/11/2013 20:28:28

21/11/2013 05:28:28

23/11/2013 14:28:28

25/11/2013 23:28:28

28/11/2013 08:28:28

30/11/2013 17:28:28

12/03/2013 2:28

12/05/2013 11:28

12/07/2013 20:28

12/10/2013 5:28 RH

(%)

Te

mp

(°C)

Pa

llets to

an

d fro

m D

ub

ai : d

ata

log

ge

r do

wlo

ad

Ce

lsius(°C

)d

ew

po

int(°C

)H

um

idity

(%rh

)

Battice

Antwerpen

Vessel leaves

Dubai Port

Sharja WH, UAE

Leave Dubai Port

Leave Sharja WH, UAE

Rotterdam

Antwerpen

Battice

Se

pte

mb

er

Octo

be

rN

ov

em

be

rD

ec.

Au

gu

st

0

10

20

30

40

50

60

70

80

90

100

0

10

20

30

40

50

60

70

80

90

100

1/01/2013 1/02/2013 1/03/2013 1/04/2013 1/05/2013 1/06/2013 1/07/2013 1/08/2013 1/09/2013 1/10/2013 1/11/2013 1/12/2013

RH (%)

gr H2O/m3

°C Dubai International aiport

Avg temperature

Max temperature

Point de rosee (avg)

Avg RH

Max RH

gr H2O/m3

Pallets trip

2013 Temperature /RH history in Dubai

20Source: http://www.wunderground.com/history/airport/OMDB/2012/5/15/DailyH

Recordings fromthe pallet

Data logger

2013 Temperature /RH historyin Liege / Bierset (close to where bobbins & fabrics were stored)

21

2013 Temperature /RH history in Kristiansand - Norway

22

TTS for SE1500

Roving age

Effect ofpackaging

Effect ofpackaging

TTS for SE1500

Roving age

UD fabric results

When Transverse tensile strength of UD laminates made by dry windingis low (<10MPa), laminates are already full of cracks prior demolding

Laminate quality

TTS for SE2020 and SE/W3030

UD fabric results

Effect of packaging

+ fabric

UD fabric results

TTS for SE2020 and SE/W3030

UD fabrics results

TTS All results

Short Beam Test results

for 2.5monthsfor 2.5months

UD Fabric drying

Epoxy laminate based on 2 «severely aged » SE1500 UD fa bricsTransverse tensile test before and after fabric drying 2 h at 105°C

2400 tex

2400 tex

Both laminates quality looked good, initial H20 in the fabrics was 0,03% (not high)

Drying could only increase the TTS from 12 to 20-22 Mpa (+70-75%)ILSS was improved from 30 to 43-46 Mpa (+43-45%)

As received Dried 2h at 105°C

Conclusions

� As reported from the field, some « old » reference sizings confirmed to be verysensitive to storage conditions (especially temperature) and demonstratedsignificant reduction of Inter Fiber properties over time.

� The newly developed sizings demonstrate much reduced degration over time in rovings and fabrics forms on Advantex and HiPer-tex glasses . They are much less sensitive to temperature, and provide significantly higher initial Inter Fiber Strength.

� After 2 years of storage at normal « western storage conditions», these new sizings still demonstrate excellent Inter Fiber properties.

� Degradation in hot and humid environment (high amount of water in the air) isstill happening most likely at the interface at the glass (hydrolysis of silane)

� Tight packaging can help => ! water might still diffuse through

� Controled moisture level can help (i.e. < 25gr H20 / Kg = 35C / 70%RH)

� Newly developed sizings ensure better laminate properties consistency

Thank you for your attention