Jan Lambrechts - LCS Belgium
- 1. © µ-Joining µC121206 121203 LCS Micro - Joining, the Adhesive Bonding Approach. Themadag Mikrocentrum Eindhoven – 6 december 2012 LCS Belgium bvba, Consultancy in Adhesive Bonding Technology www.lcs-adhesivebonding.com Where it’s all about … • Introduction … always with examples • Bonding as alternative for … • What is bonding ? The theory … • Surface Treatment Methods • External Influences • Adhesive Types • Design with Adhesives • Examples including equipment and QC • Conclusion NASA – Spaceshuttle – Heatshield vs Medical Needle – PP to Inox Bonding: an alternative for … • Welding: – Electric Arc Welding, – Ultrasonic Welding, – Laser Welding • Soldering • Screws, Bolts & Nuts • Clinch-nails & Rivets • Folding, Pressing en Flowdrilling • Clasp constructions & Springs • Sewing, Stitching & Stapling Advantages of Adhesives • Easy & Fast: less rework • Also for dissimilar materials – e.g. metal-plastic & thick-thin • Higher Strength: uninterrupted joint – No or less weak points • Improved Stress-distribution & -reduction – Higher fatiguestrength • Sealing: corrosion prevention – Liquid- & gastight • Damped Vibrations – less Noise S&R • Light: weight reduction • Esthetic: invisible • Bonding also “Thin” & “Small” components • Less componentsµ LCS Adhesive Bonding bvba Copyright © 2012-06-07
- 2. Pseudo-disadvantages of Bonding •It’s “Chemistry” ! It’s a mess !? = Operator dependent • Environmental aspects: – Water based adhesives – Recycling of adhesive and cleaners • Cleanliness of substrates • Design flexibility: is manageable • Speed: adhesive type dependent • Dangers: exothermic reactions, H&S • Difficult Disassembly: recycling • Limited Strength & Temperature Resistance Sticking as a Gecko – IFAM • Subtle hairs with a molecular bond: van der Waals forces What’s “Bonding” ? Definition Joining of two substrates by means of a third medium = the adhesive Adhesion vs Cohesion LCS 100218 Copyright LCS ® 18 What’s “Bonding” ? Mechanisms (cfr Wikipedia) • Vanderwaals: – Glassplates experiment • Chemical: – Si primer • Mechanical: – Surface roughness But what’s really on the ‘Surface’ ?! Surface condition of substrates !!! Why Surface Treatment ? • Strength: adhesion - cohesion ( rupture ) • Wetting ( > 40 Dyne/cm) • ‘Contact Angle’ measurement • Watertest Pretreatment of substrates • Degreasing: cloth, vapour, ultrasonic • Grinding: roughen = > surface • Blasting: grit-, ice- . NON-recirculating ! • Primers: silanes – thickness = µm • Chemical etch: bv Aluminium • Flame & Corona: foil & sheet • Plasma: vacuum & atmospheric – CA! • Laser: surface structure change Failure Types • Cohesive failure: in the adhesive • Adhesive failure: on the surface of at least one of the substrates • Material Failure: one of both substrates • Mixed Failure: a combination of the above LCS Adhesive Bonding bvba Copyright © 2012-06-07
- 3. Failure Types Medicalneedles • Cohesion failure: lack of cure • Material failure: plasma treated + fully cured Surface Treatment with Atmospheric Plasma – Video External Influences • Time: aging – degradation in function of time • Temperature: -change en thermoshock – under the hood: -55° tot +125° C C • Vibrations & Shock: noise - S&R • Chemical: salt + humidity = corrosion • Radiation: X-ray, α-, β-, γ-radiation – Radioactive – Light: UV degradation – color permanency • Medical: USP Class VI – ISO 10993 - sterilisation, biocompatibility, citotoxicity Adhesive Types - Graph • Epoxy: highest performance, chemical resistant • Polyurethane: humidty sensitive, cheap • Silicone: flexible, price ↑, Mix-Ratio, Visc ≠ f(T) • Phenolics: high temperature applications • UV & light- curing: fast, price ↑, light sensitive • Acrylates: highest strength, smell, initiators • Cyanoacrylates: moisture cure • Anaerobics: thread lock – metal+ & air cut off • Hybrids : EP/Si, PU/EP, UV + moisture or T … • Exotics: polybutadiene, MS-polymer, PSA, … • Hotmelts: cheap, reactive types, performance • Tapes: single and double sided • Ceramic : HT – Waterglass Ink Cartridges Gas Filtration Heat Exchanger Solvent Based Adhesives • Medical disposables: – Stress Cracking • Urgency repair of panty’s: – Acetone based nail remover • Solvent alternatives Adhesive Types – UV & LIGHT Curing • Medical needles • Glass & plexiglass structures • CD – DVD lens focus mechanism • ‘Carglass’ repair • Jewelry – Cristal’ clear • Refractive index • Non-yellowing • Fast curing • No oxygen inhibition – not tacky • Strong Health & Safety – H&S - That’s why there are Safety Measures … Design = alternative thinking • Tensile - Trekbelasting • Shear – Afschuiving L&R – Best for Bonding Applications • Cleavage - Splijtbelasting • Peel - Afpelbelasting Examples (cont’d) • Tea bags • Medical Needles en Catheters • Curing of Adhesives - Timing • Ra-ra-ra what’s this ? • Glucose Test • Blood Tubes • Detector in Toothbrush • Modelbouw • Balloon Catheder • Pacemakers & Hearing Aids • Surgical Glue & Dental Surgery • Nageltrends • Scanner Sensors • CA Rubber Bonding • CD/DVD Laser • Motor Control LCS Adhesive Bonding bvba Copyright © 2012-06-07
- 4. • RFID –Identification Systems • SMD in Electronics • Watch Mechanism with Chip • Stacking Potentiometers • Piezo Diesel Injection • Piezoelectric Evaporation Device • Biological Pest Control • Shaver Blade Cover • Dosing Equipment – Volumetric – XYZ – 2K • Nano dispensing equipment - 1 mm - 10 nl • Chip Packaging in Micro-Electronics • Fiber-Optics Quality Control with Vision System • A: non Fluo • B: non Fluo • C: OK • D: Defect A few Trends • Multiple functionalities: Vibration dampening - S&R • More composites and ‘all-in’ adhesives • Increasing Price pressure ↑ : Lopez effect - raw materials & energy price increases • Nanotechnology in adhesives • It all happens on the surface, less in the adhesive • Selfhealing Adhesives • More automation with adhesives • More ‘Bonding’ for your new Application Conclusion The only chance realising bonding projects successfully, is that the “Triumvirate” of – the customer with his project – the glue manufacturer with the adhesive – the machine manufacturers with their equipment is working intensively and expertly together, from the design phase on and on all aspects of the application. Success Guaranteed ! Thanks for your attention, and we welcome you in ’The Adhesive’s World’ LCS – Your partner in Adhesive Bonding LCS Adhesive Bonding bvba Independent Consultancy in Adhesive Bonding Technology Ing. Jan A. LAMBRECHTS MSc. Bergenstraat 84 B-3053 Haasrode – Leuven +32-(0)16-38 90 45 +32-475-45 48 98 jan.lambrechts@consultant.com www.lcs-adhesivebonding.com 121203 LCS © µ-joining µC 121206 LCS Adhesive Bonding bvba Copyright © 2012-06-07