Adhesives and Bonding Technologies for Multi Material Mix Design

Dr. Stefan Schmatloch Lead R&D Manager DOW Automotive Adhesives Dr. Sergio Grunder R&D DOW Automotive Adhesives Dr. Andreas Lutz R&D Director DOW Automotive Adhesives

Meyer Galow /

GDCh award for

BETAFORCETM

2015

R&D 100

Award for

BETAFORCETM

2016

Golden Mousetrap

Award

BETAFORCETM

2017

2018

Why Weight Savings?

global vehicles emissions legislation

powertrain improvements alone cannot achieve the fleet fuel efficiency and emissions targets

10% less mass up to +7% fuel efficiency

2

Source: www.icct.org

Source: www.icct.org

+

US Car Average

EU Car Average

CALIFORNIA

1500 2000 2500 3000 3500 4000 4500 5000 5500

Vehicle Mass (lbs)

US Lt Truck Avg.EU Average

EU Car Average

US Car Average

US Lt Truck Avg. Gasoline car

Diesel car

Gasoline Hybrid

Diesel Hybrid

EU 2020 targetCA 2020 target

EU 2015 target

US 2015 target

330

300

270

240

210

180

150

90

60

30

CO

2 E

mis

sio

ns g

/km

US Car Avg.

Industry Trend increasing usage of lightweight metals

DOW CONFIDENTIAL - Do not share without permission

bonded VORAFORCETM 5300 CFRP rear wall enables approx. 30% increase of torsional stiffness

BETAFORCETM 9050M continuous bond line results in significant improvement of crash resistance

4

industry trends CFRP

CFRP rear wall, www.audi-mediacenter.com

Structural Adhesive Technologies vehicle weight reduction by multi material design

5

Full Body Bonding Module Bonding Full Body Bonding

BETAFORCE™ Polyurethane Technology

Body Shop Paint Trim

Shop Repair 80-160°C, 30’ 180°C, 30’ 25°C

BETAMATE™ Epoxy Technology

tail gate and closure

applications: polypropylene and

SMC composite bonding

full car body assemble: high

performance composite to metal

bonding

battery assembly: thermal conductives

structural bonding and sealing

Audi A8 space frame design

D. Roquette, F. Meyer, L. Herbeck, High Volume

Manufacturing of Carbon Fiber Reinforced Plastic

Body in White, Automotive circle, Materialien des

Karosseriebaus, Bad Nauheim, 2017

Structural Adhesive Technologies

Increased Energy Management Capability continuous bond lines improved crash performance

Enabling Multi Material Mix Design for Light Weighting greater design flexibility

non-traditional materials

non-destructive joining technique, retained integrity of substrates

Weight Reduction optimized steel design (-20%)

aluminum intense design (- 40-50%)

carbon fiber intense design (-60%)

Enhanced Vehicle Performance increased static stiffness: 20%

increased dynamic stiffness: 2 – 3%

climate independent performance

Improved Manufacturing Processes fast low cost joining and DT curing elimination of surface pre-treatment processes process speed improvement of 50 -100%

Design

Safety

Environment

Savings

6

Durability &

Driving Comfort

800

400

100

50

35 30 25 20 15 10 5 1

Elongation %

Lap Shear Strength (Mpa)

Structural Epoxy Adhesives:

BETAMATE™

PU Adhesives & Sealants: BETASEAL™, BETALINK™

Semi-Structural PU Adhesives: BETAFORCE™

PU Sealants: BETASEAL™, BETAFILL™

Structural PU Adhesives: BETAFORCE™

Epoxy Adhesives:

BETAMATE™ Flex

Epoxy Hybrid Adhesives:

BETAMATE™

BETAFORCE™ Polyurethane Technology

Body Shop Paint Trim

Shop Repair 80-160°C, 30’ 180°C, 30’ 25°C

BETAMATE™ Epoxy Technology

Automotive Manufacturing Processes body shop vs. trim shop process materials

7

Adhesive Portfolio Meets Requirements

portfolio tailored to application needs

robust material properties over wide temperature range

long-term durability of bond assembly

combination of high modulus and high tensile strength despite high elongation at break

robust substrate bonding (e-coat, SMS, CFRP, etc.) for hybrid materials assembly

tailor made heat accelerated curing technologies

thermal conductive adhesives for structural battery assembly

8

open time at 23°C [min]

elongation at break

BETAFORCETM 2810LV plus

BETAFORCETM 2817 V1

BETAFORCETM 9050M

BETAFORCETM 2806

BETAFORCETM 2800 TC

ela

sti

c m

od

ulu

s [

MP

a]

9

Improved Physical Properties for Driving Comfort ambient climate independent adhesive joint properties

high bulk property performance (modulus, tensile strength) and durable adhesion performance enable

multi material mix design and contribute to overall part and vehicle stiffness

conventional adhesive technology

change of physical properties after exposure (temperature and humidity)

change of physical properties under dynamic load

0

2

4

6

8

10

12

14

16

18

0 20 40 60 80 100

sh

ea

r s

tren

gth

[M

Pa

]

exposure times [days]

CFRP BETAFORCE(TM) 9050M e-coat BETAFORCE(TM) 9050M

conventional adhesive

150

200

250

300

350

400

0 2 4 6 8

mo

du

lus

[M

Pa

]

exposure time [days]

BETAFORCE(TM) 9050M conventional technology

exposure: 70C water immersion, -20C freeze shock. exposure: climate change cycle beween -30C and 80C.

< 20% change

< 20% change

BETAFORCETM 9050M

10

Improved Curing Kinetics for Manufacturing Process Optimization latency & humidity independent curing – flexible logistic processes

0

20

40

60

80

100

120

140

160

0 50 100 150 200 250 300

mo

du

lus

[M

Pa

]

curing time [min]

manufacturing processes may require part shipment or part handling shortly after adhesive joining in

uncontrolled climate conditions

conventional adhesive technology

need for additional mechanical fixations

need for long curing time to reach end-cure properties or handling strength (modulus and shear strength)

fast curing only in combination with short open times (no latency)

BETAFORCETM 9050M latency

slow initial cure at low viscosities followed by

rapid cure at ambient temperature to reach

end cure properties after short curing times

11

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

14000.00

16000.00

18000.00

0 500 1000 1500

co

mp

lex

vis

co

sit

y [

Pa

.s]

time [sec]

Improved Curing Kinetics for Manufacturing Process Optimization latency & heat cure – flexible manufacturing processes

heat accelerated cure

latent curing kinetics

low press-in forces to reach targeted bond gap thickness

also after long open and assembly times

flexible assembly processes

heat accelerated processes fast obtained handling

strength and for very short takt times

good adhesive bead compressibility with increasing

curing time with latent BETAFORCETM technologies

poor adhesive bead compressibility with conventional

adhesive technologies

12

latent curing kinetics and shear thinning properties contribute to robust application processes

with prolonged mixer dwell times

without frequent change of static mixers (waste reduction)

enabling reduction of flush cycles (waste reduction)

with robustness over a wide range of material and ambient temperature

with stable application pressures and robust application processes

Improved Latency for robust Application Processes

0

10

20

30

40

50

60

0 20 40 60 80ap

plic

ati

on

pre

ss

ure

[b

ar]

No of applications without mixer flushing

peak pressure POLY peak pressure ISO

application pressure POLY application pressure ISO

Left. good mixing quality.

Right. poor mixing quality.

excellent adhesion performance

as result of robust applicability

13

Improved Adhesion for Manufacturing Process Optimization reduction of surface pretreatment processes

adhesion to carbon fibre re-enforced plastics (CFRP)

removal of mold release agents necessary in order to obtain robust adhesion

conventional adhesive technology

need for complex cleaning processes: grinding, korund (Al2O3) blasting processes followed

by removal of dust via washing or vacuum

need for difficult quality control for mechanical cleaning processes

need for application of additional adhesion promoters

BETAFORCETM 9050M

improved adhesion performance for simplified processes without the need for mechanical,

physical or chemical activation of the bond line

poor wetting and resulting adhesive failure

to CFRP of conventional adhesives

good adhesion performance of BETAFORCETM

9050M to washed CFRP substartes

14

Improved Adhesion for Manufacturing Process Optimization CFRP wash process

0.00

5.00

10.00

15.00

20.00

25.00

0 50 100 150 200

sh

ea

r s

tren

gth

[M

Pa

]

curing time [h]

CFRP grinded, 1x CFRP heptane clean, 1x CFRP water wash, 1x

0.00

5.00

10.00

15.00

20.00

25.00

0 50 100 150 200

sh

ea

r s

tren

gth

[M

Pa

]

curing time [h]

CFRP grinded, 2x CFRP heptane clean, 2x CFRP water wash, 2x

0

5

10

15

20

25

0 50 100 150 200

sh

ea

r s

tren

gth

[M

Pa

]

curing time [h]

CFRP grinded, 10x CFRP heptane clean, 10x CFRP water wash, 10x

mold release study

CFRP surface contamination with up to 10 fold

access of mold release

robust adhesion, unchanged curing kinetics and

end cure properties independent from cleaning

process: mechanical grinding vs. heptane

cleaning vs. water wash process

confirmed long term durability of bonded joints