Radiation Curing AIPI Milano, 15 May 2014 DELO Stefano Farina
Product description - Properties and advantages Properties: one-component curing at room temperature curing with UVA- or visible light PHOTOBOND: radiation curing acrylates KATIOBOND: radiation curing epoxy resins DUALBOND: radiation curing epoxy resins additional heat curing is possible Advantages: fast curing in 1 to 60 s elongation at tear 1 up to 300 % no efflorescence processing time controllable through irradiation
Fields of application Smart Cards Glass furniture Loudspeakers for mobile phones Switches, relays, sensors for plant construction and automotive industry
Electromagnetic spectrum For radiation, curing visible light, UVA and UVB (conditionally) are used
Radiation properties Influence of wavelength on photo energy and penetration depth
Transmission spectrum Transmission of different materials Glass Transmission in % PC with filler Wavelength in nm UV-light Visible light
DELO s lamp range DELOLUX 20 DELOLUX 50 DELOLUX 80 DELOLUX 03 S DELOLUX 04 DELOLUXcontrol
Discharge bulb technology (till yesterday ) DELOLUX 03 S DELOLUX 04 DELOLUX 06
Medium-pressure mercury bulbs Setup of the radiator Base Quartz pipe Electrodes Current passage Gas filling
Medium-pressure mercury bulbs Emission spectrum
Medium-pressure mercury bulbs Influencing of the emission spectrum of lamps by doping e.g. with iron (F) Used in DELOLUX 03, DELOLUX 06, DELOLUX 10
High-pressure mercury bulbs Without doping Used in DELOLUX 04
Aging of bulbs with electrodes Decrease in intensity of an iron-doped medium-pressure mercury bulb UVA-Intensity in % Tolerance band Burning time
Intensity measurement - DELOLUXcontrol The irradiance of curing lamps is influenced by aging of the curing lamp and thus decrease in intensity contamination of the lamp disks Therefore: Intensity measurement in the following possible versions: discontinuous measurement (e. g. every day) continuous measurement combination of both versions
LED lamp technology Lamp optimized for the adhesive Fast curing of all UV- and light-curing adhesives Unchanging intensity of the LEDs for optimum process reliability Low maintenance, spare part and operating expenses (TCO - total cost of ownership) Also ideal for short cycle times
Radiation curing: LED Technology (from today on ) Easy: intensity adjustment from 0 100 % Robust: no moving shutter Energy-saving: power on demand life time = curing time
LED-Technology Wavelength adjusted to the photoinitiator. Light completely usable for adhesive curing Fast processes possible
Discharge lamp UV LED Blue LED 0 mm 2 mm Adhesive layer 4 mm 6 mm 8 mm Substrate 10 mm 350 390 nm 390-480 nm 480 540 nm 540 590 nm 590 800 nm
Comparison of discharge and LED lamps Discharge lamps Radiation exit area Power consumption Intensity Emission spectrum DELOLUX 03 S area lamp 212 x 170 mm 400 W 70 mw/cm² UVA at a distance of 100 mm 325 600 nm UVA + VIS DELOLUX 04 light guide lamp light guide Ø 8 mm, 5 mm, 3 mm double 380 W 8,000 mw/cm² UVA at the light guide outlet 315 500 nm UVA + VIS LED lamps Radiation exit area Power consumption Intensity Emission spectrum DELOLUX 20 LED area lamp 101 x 101 mm max. 200 W 200 mw/cm² with type 400 250 mw/cm² with type 460 400 + 460 nm DELOLUX 22 LED area module 55 x 23.3 mm approx. 20 W > 200 mw/cm² LED 400 + 460 nm DELOLUX 80 LED spot lamp Ø 16.9 mm with type 400 and 460 Ø 23.0 mm with type 365 Max. 200 W > 1,000 mw/cm² LED at the optical outlet 365, 400 + 460 nm DELOLUX 50 LED spot lamp Ø 8.6 mm max. 200 W up to 12,000 mw/cm² LED 365 nm
Overview of photo-initiated adhesives Photoinitiated adhesives Radical-curing acrylates DELO-PHOTOBOND Cationic-curing epoxies DELO-KATIOBOND Cationic-curing epoxies DELO-DUALBOND UVA-curing 320-400 nm Radiation-curing 380-450 nm UVA-curing 320-400 nm Light-activation 400-550 nm Light- and/or heat-curing 320-400 nm
DELO-PHOTOBOND - Radical polymerization Monomers: ester of acrylic acid Photoinitiator: I H H C = C H C = O O R 2 1. Decomposition of the photoinitiator in free radicals by irradiation with UV- and visible light respectively: I light R 2. Opening of the double-bond and formation of monomer radicals: R + C = C R - C - C Irradiation must continue until complete curing is achieved! Thus at least one component must be translucent! 3. Chain growth leads to adhesive curing: R - C - C + nc = C R - [C - C] n - C - C
DELO-PHOTOBOND - Options for processing Light- or UV-curing Dispensing Joining Curing
DELO-PHOTOBOND - Curing process 160000 140000 120000 Viscosity [Pas] 100000 80000 60000 40000 20000 0 0 5 10 15 20 25 30 35 40 45 50 Time t [s] DELO-PHOTOBOND 4302 DELO-PHOTOBOND 4436
DELO-PHOTOBOND - Fundamental product properties Every second cell phone is manufactured using DELO-PHOTOBOND Fast curing in 1 s possible Optically stable in the Xenon test at 10-fold sunlight intensity Wide range of elasticity from 4 to 300 % elongation at tear Great layer thickness possible up to 5 mm Hardly exothermal heat development during curing Humid surfaces through oxygen inhibition with some products Biocompatibility: Licenses for medical engineering according to USP Class VI are existent
DELO-KATIOBOND - Cationic polymerization Monomers: Epoxies Photoinitiator: I 1. Decomposition of the photoinitiator in cation and counterion by irradiation with UV- and visible light respectively: light I R + +Y - 2. Cationic opening of the epoxy ring and formation of monomer radicals: C - C O + R + +Y - R2 R3 R1 C - C O R4 C - C O+ R + Y - 3. Chain growth through cationic opening of further epoxy rings (can be extremely exothermal) Irradiation must not be effected until final curing Opaque components can therefore also be bonded Please notice: The complete adhesive amount needs to be irradiated
DELO-KATIOBOND - Options for processing Light- or UV-curing Dispensing Joining Curing Activated by light Dispensing Activating Joining and curing without further irradiation
DELO-KATIOBOND - Curing process 1200000 1000000 Viscosity [Pas] 800000 600000 400000 200000 0 2 min 3 h 5 h 6 h 24 h Time t [s] Activation: 0,8 s / 200 mw/cm² Activation: 0,4 s / 140 mw/cm²
DELO-KATIOBOND Pre-activation times Dependence of open time from preactivation time Processing times DELO-KATIOBOND 45952 6 5 Test (drops) 4 3 2 1 Preactivation time Open time 0 2 4 6 8 10 12 14 16 Processing time / s Parameter: 10 mg drops on glass object holders Irradiation with 50 mw/cm²
DELO-KATIOBOND - Fundamental product properties Three out of four smart cards are manufactured with the use of DELO-KATIOBOND Low ion content (important for electronic applications) Temperature range of use up to 150 C Preactivation possible (bonding of opaque components possible) Biocompatibility: Licenses for medical engineering according to USP XXIII Class VI are existent Tension-equalizing with an elongation at tear up to 50 % Dry surface Exothermal curing
DELO-KATIOBOND - Climate resistance 9 Compression shear strength [MPa] 8 7 6 5 4 3 2 Compression shear strength PC/Al Compression shear strength PC/Al after 4 w climate 1 0 DELO-KATIOBOND 4557 DELO-KATIOBOND 4571 DELO-KATIOBOND 45952
DELO-KATIOBOND - Temperature resistance 30 7 Tensile strength [MPa] 25 20 15 10 5 Elongation at tear [%] 6 5 4 3 2 1 0 DELO-KATIOBOND 4594 0 DELO-KATIOBOND 4594 Tensile strength [MPa] Tensile strength [MPa] 1000h/160 C Elongation at tear [%] Elongation at tear [%] 1000h/160 C Measurands at room temperature each.
DELO-DUALBOND - Fundamental product properties Curing with heat (minimum 120 C) Fast curing of visible areas with light For components with shadowed areas Dry surface Temperature range of use up to 150 C Tension-equalizing with an elongation at tear up to 50 % Fast heat-curing e.g. 3 min at 130 C