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
May 2014 7
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
May 2014 19
� 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