Quick and process-reliable bonding of fastening elements

0250/07.02

ONSERT

A joint project between

An efficient connection

Technological progress, reduced development times, legal changes, etc. result in new requirements on the fastening and assembly technology. As a result, Böllhoff, as a specialist in mechanical joining technology, and DELO, as a specialist for intelligent bonding technology, have together developed a new fastening system. The most important factor was process-reliable curing of adhesives with ideal cycle times as well as geometric designs of fastening elements.The ONSERT technology is the result – quick and process-reliable bonding of fastening elements. The innovativejoining technique provides ideal preconditions for manifold applications in different areas. Currently, there are twovariants – ONSERT basic and ONSERT plus.

ONSERT basic

Principle and ideaBöllhoff and DELO developed a threaded bush which, regarding geometric design, is provided with a sufficientbonding surface area due to an enlargement in diameter in the lower area. The cavity in the contact surface ensures that reproducible layer thicknesses in the adhesive layer are maintained and that the adhesive wets the complete component surfaces. ONSERT basic can be bonded to sheets, printed circuit boards and plastic housings with heat- or dual-curing adhesive systems.

Advantages■ Prevention of leakages and overlaps on the back■ Fastening elements do not become apparent on

the visible side through heat input during laser welding or soldering

■ High fitting values and compensation of impulsivestress

■ Connection to freeform surfaces

ONSERT plus

Principle and ideaThe ONSERT joining technique is a real alternative, not only for particularly small but also for large wall thicknesses.If a housing with material accumulation is produced by injection moulding, visible shrinkage (sink marks) often occurs after cooling down – this problem can be avoided with ONSERT plus. ONSERT plus allows quick, form-closed bonding on optimised fins on the corresponding component. As an alternative to bosses produced with the original mould, the system provides new design possibilities due to subsequent joining.

Fastening elements, such as well-proven AMTEC® thread inserts, are coated with transparent plastic (adhesiveboss) and are then fitted using light-curing adhesive systems. Adhesive bosses can be produced in various designs, e.g., with internal threads, bolt threads, ball bolts or snap-on fasteners.

Advantages■ Reduction/prevention of sink marks■ Shorter injection cycles■ Easier tooling concepts■ Standardised elements■ Suitable for semi-automated and fully

automated processing■ Short curing times (< 5 sec)

Adhesive Substrate Release forceFmax in [N]

DELO-MONOPOX aluminium 114AD066 stainless steel 120DELO-MONOPOX aluminium 241AD295 stainless steel 442DELO-DUALBOND aluminium 188AD420 stainless steel 181

600

500

400

300

200

100

0

DELO-PHOTOBOND DELO-PHOTOBOND DELO-PHOTOBOND GB VE57288 PB493 PB437

Tensile strength [N]

unag

ed

afte

r ag

ing

unag

ed

afte

r ag

ing

unag

ed

afte

r ag

ing

•

168 h at +40°C /100% r. h.

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Process description

ONSERT basic

1. DispensingThe one-component, heat-curing acrylate or epoxy resin adhesive DELO-MONOPOXis dispensed onto the housing, e.g., from the Euro cartridge.Dispensing is carried out from the Euro cartridge pressure tank DELO-XPRESS 911via a constricted tube valve. The pressure tank is controlled with the control unit DELOMAT.

2. JoiningThe fastening element is joined onto the housing.

3. CuringDELO-MONOPOX adhesives are either oven-cured (e.g., 20 min at +130°C), induction-cured or cured using a thermode (typical curing time approx. 30 s each).

As an alternative to DELO-MONOPOX adhesives, you can also use DELO-DUALBOND products with combined light and heat curing. The adhesive isdispensed in such a way that a fillet is created. A DELOLUX curing lamp results inquick fixing within seconds (< 5 s). Afterwards, the areas inaccessible to light arecured by heat (e.g., 3 min at +130°C).

ONSERT plus

1. DispensingThe one-component, UV- and light-curing acrylate adhesive DELO-PHOTOBOND isapplied to the bar.The adhesive is dispensed with the pressure tank DELO-XPRESS 951 via up to fourconstricted tube valves from the one litre container. The control unit DELOMAT isused for control.

2. JoiningThe adhesive boss is joined onto the plastic plate.At least one joining partner – in this case the adhesive boss – must be translucent inthe absorbing range of the adhesive.

3. CuringDELO-PHOTOBOND is irradiated for several seconds (e.g., < 10 s) – until finalstrength is reached.All DELOLUX curing lamps, such as the LED lamp DELOLUX 80, are suitable.

•

Subject to technical change.Reprinting, even in extract form, only permitted with express consent.Observe protective note according to DIN 34.

Böllhoff Verbindungstechnik GmbHArchimedesstraße 1–4 · 33649 Bielefeld · Germany

Phone +49 (0)521 /4482-05 (326) · Fax +49 (0)521 /4482 -658www.boellhoff.com · fasteningtechnology@boellhoff.com

DELO Industrial AdhesivesDELO-Allee 1 · 86949 Windach · Germany

Phone +49 (0)8193 /9900-0 · Fax +49 (0)8193 /9900 -144www.delo.de · info@delo.de