May 2014 1

ONSERT® technologyAIPI – Milano, 15 May 2014DELO – Stefano Farina

Overview

May 2014 2

� Introduction

� ONSERT® joining technology

� Light-curing adhesives in light-weight construction

� Applications of ONSERT® technologyin light-weight and automobile construction

Substrate properties

May 2014 3

Critical combinations of component materials:

In many cases, the properties of the component materials to be bonded involve special requirements on the joining technology.

High-strength steel � Heat input in the joining area is critical� Forming methods only conditionally usable due to mechanical

properties

Thin sheet metal � Thermal methods complicated from t < 0.6 mm� Forming methods often unsuitable and critical regarding the

process due to punctual stress

Fiber plastic composites � Thermal methods rarely usable� Forming methods normally not usable due to missing ductility� Blind rivets and blind rivet nuts complicated and often unsuitable

due to preliminary drilling (damage to fiber structure)

Pretreated surfaces(lacquered, polished, cathodic dip coating)

� Thermal methods not usable� Forming methods only conditionally usable (corrosion protection

and appearance)

Glass � Removable connections only feasible with great efforts

ONSERT® joining technology

May 2014 4

� Böllhoff Verbindungstechnik – specialist for mechanical joining technology and DELO Industrial Adhesives – specialist for intelligent bonding technologyhave jointly developed an new connection system: ONSERT®

� Fast and process-reliable combination of adhesive technology and removable screw connections

� Innovative and flexible joining method with versatile possibilities of use in a broad variety of industries.

ONSERT® connection elements

May 2014 5

ONSERT® plus – rib connection

� No sink marks like with injection molding

� Fast, form-closed joining technology

� Design freedom due to subsequent joining

ONSERT® basic – area connection

� Area connection to CFRP, GRP, metal, plastic, etc.

� Variable threaded inserts possible (screws, threaded sockets, snap connections)

� Design freedom due to subsequent joining

ONSERT® process description

May 2014 6

Dispensing

� Application of the one-component, solvent-free DELO-PHOTOBOND acrylate

Joining

� Joining of the adhesive dome onto the plastic plate

� At least one component must be permeable to light within the adhesive’s absorption range

Curing

� Irradiation of the adhesive until final strength (e. g. < 10 seconds)

� Suitable: all DELOLUX lamps (z. B. DELOLUX 80 LED lamp)

Advantages of light-curing adhesives

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Very fast curing � High production volumes possible

� In-line process control possible

“Curing on demand” � Curing proceeds only when required (upon irradiation)

One-component � No mixing system required

� Long processing time

� No mixing errors

“Cold curing” � Protection of temperature-sensitive components

� Low energy costs

� Components are not thermally stressed

Solvent-free � No solvent emission

� 100 % solid/adhesive

Advantages of light-curing adhesives

May 2014 8

General

� Non-destructive & component-compatible joining technology

� The appearance of the visible side / joining side is not impaired

� Higher material flexibility

� Higher flexibility in the joining technology

Light-curing acrylates

� Very fast curing without thermally stressing the components

� Simple process and high degree of automation possible

� Final strength directly after irradiation (no postcrosslinking)

Light-curing adhesives: Epoxies & acrylates

May 2014 9

Basic resin Epoxy Acrylate

DELO family DELO-KATIOBOND DELO-PHOTOBOND

Curing Cationic polymerization Radical polymerization

Type of polymer created* polyether Polyolefin (polyacrylate)

Curing speed /build-up of adhesion

Activation in a few seconds Curing in the range of seconds

ONSERT® in automotive light-weight construction

May 2014 10

Use of welded studs in the carbody

� Ideal for sheet thicknesses below 0.5 mm

� Can be used on non-metal materials, such as CFRP and lacquered surfaces

� Very fast curing until final strength within seconds (< 10 s)

� Appearance of visible side is not impaired

� 11 time less energy required

ONSERT® in automotive light-weight construction

May 2014 11

Previous method: stud welding

Alternative method: ONSERT ®

Mechanical properties

May 2014 12

FA

Onsert: PC with threaded stud (M5); substrate: steel; component surface: CDC; adhesive: DELO-PHOTOBOND AD494; ; layer thickness: 0.2 mm; light source: DELOLUX 80; irradiation time: 5 seconds; lamp distance: 32 mm

ML

Bond strength with ONSERT® basic FA [kN]

0,00

0,50

1,00

1,50

2,00

1 2 3 4 5

Pul

l-off

stre

ngth

[kn]

]

1 – 4 = test series / 5 = average value

Break-away torque with ONSERT® basic ML [Nm]

1 2 3 4 5

7,00

10,00

8,00

5,006,00

4,003,002,001,000,00

9,00

Bre

ak-a

way

torq

ue []

Nm

1 – 4 = test series / 5 = average value

Mechanical properties

May 2014 13

Bond strength with ONSERT® plus FA [kN]

Break-away torque with ONSERT® plus ML [Nm]

ML

FA

Onsert: PC adhesive dome (T5); substrate: ABS unfilled; pretreatment: Onsert: low pressure plasma; ribs: atmospheric plasma

1 2 3 4

15,0

10,0

5,0

0,0DELO-PHOTOBOND

AD VE 57288DELO-PHOTOBOND

PB437DELO-PHOTOBOND

AD494

Bre

ak-a

way

torq

ue []

Nm

Adhesive

0,0

1,0

2,0

3,0

DELO-PHOTOBONDAD VE 57288

DELO-PHOTOBONDPB437

DELO-PHOTOBONDAD494

Pul

l-off

stre

ngth

[kn]

]Adhesive

untreated after surface activation

Aging

May 2014 14

VDA climatic change test

� Element Threaded stud (PC)

� Adhesive DELO-PHOTOBOND PB AD487

� Layer thickness 0.2 mm

� Light source DELOLUX 04

� Irradiation time 4 s

Storagein Skydrol (hydraulic fluid in aviation)

� Element Retainer (PPSU)

� Adhesive DELO-PHOTOBOND AD492

� Layer thickness 0.1 mm

� Light source DELOLUX 03 S

� Irradiation time 180 s

� No decrease in bond strengthafter storage for four weeks

� No signification decrease in bond strength after 1,000 h

Testing of pull-off force

May 2014 15

Fracture images

Adhesive failure on both sides from CFRP/GRP & PC

Component failure

Adhesive failure from PC or GRP/CFRP

Test setup for mechanical testing

Pull-off testZwick, DIN EN 1465, v = 10 mm/min

ONSERT® on CFRP

May 2014 16

0,00

500,00

1.000,00

1.500,00

2.000,00

2.500,00

1 h rt 7 d 85 °C/85 % r.h. 10 d VDA climaticchange

F m

ax []

N

CFRP withoutpretreatment

CRP, corundum-blasted

Onsert: PC with threaded stud (M5)

Substrate: CFRP (epoxy resin)

Adhesive: DELO-PHOTOBOND AD487

Layer thickness: 0.2 mm

Light source: DELOLUX 80

Irradiation time: 5 s

Lamp distance: 32 mm

Tensile and compression stress

May 2014 17

Tension = goodCompression = good

Tensile and compression shear stress

May 2014 18

Torque = good

Tensile shear = good Compression shear = good

Peel and split stress

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� Force transmission as close to the ONSERT ® base as possible

� Ensure equalization of tolerances of the attached components (above disc spring)

Peeling = bad

Peel and split stress

May 2014 20

� Therefore, it must be ensured that the component is supported by the ONSERT ®,and not by the substrate!

Static stress = bad

Strength approx. 1/100 of pull-off values

Use on rib structures

May 2014 21

Screw connections at plastic form components

ONSERT® application example: Vacuum cleaner

Area connections

May 2014 22

Removable and irremovable snap connections

ONSERT® application example: Washing machine

Area connections

May 2014 23

Bondable SnapLock ® elements

ONSERT® application example: Automotive

Area connections

May 2014 24

Stand-offs for aviation

ONSERT® application example: Aerospace