Download - Laser Transmission Welding of Polymers
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PLASTIC WELDINGwithLASER SYSTEMS
Distributed in the UK by:
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vs.
Transparent joining part
Welding seam
Absorbing joining part
Melt zone
Lasers radiation
Laser Transmission Welding• Basics• Concepts• Examples
Material requirements:• Top part laser-transparent material• Bottom part laser-absorbent material• Compatible materials
- Melt Temp- Chemical Compatibility
Process requirements:• Good thermal contact• Pressure• Clear access for laser
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vs.
Transparent joining part
Welding seam
Absorbing joining part
Melt zone
Lasers radiation
Laser Transmission Welding• Basics• Concepts• Examples
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Joining part:• “no” absorption dopt >> d “no“ heating• volume-absorption dopt d heating across the whole thickness • surface-absorption dopt << d near surface heating
IT
Absorption Characteristics• Basics• Concepts• Examples
IL
dopt >> d
IRd
dopt << d
IL
IRd
IL
IR
IT
dopt d
d
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Laser• Basics• Concepts• Examples
CO2-Laser ND:YAG-Laser HPDL*
type of active mediums gas solid state semi conductor
wavelength [nm] 10600 1064 800 - 980
max. power cw [KW] up to 40 up to 5 0.05 up to 5 (modular)
intensity in focus [W/cm2] 106 -108 105 - 108 103 - 105
efficiency [%] 5 - 10 3 - 10 30 - 50
size (Head) [cm3/W] ~200 ~20-50 ~1
maintenance [h] ~1000 ~800 (lamps) no maintenance
properties of HPDL (diode laser) • high efficiency • compact• low-maintenance/ high life time• low beam intensity
HPDL*= high power diode laser
Lasers in material processing
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Weldable Materials
• Thermoplastics ~ Amorphous and semi-crystalline polymers (like - like) materials welded successfully:
• ABS, COC, PA, PBT, PC, PE, PMMA, PP, PS, SAN, ... • Combinations of different but compatible thermoplastics include:
• PMMA-ABS, ABS-PC, ABS-SAN, PMMA-PC…. • Thermoplastic Elastomers:
• Thermoplastic Elastomer to Thermoplastic Elastomer • Thermoplastic Elastomer to non-elastomeric thermoplastics
• Colour-combination possibilities:• Black - Black (special non-carbon colouring in one part)
• Transparent – transparent (with addition of “clearweld”)
• Other colours with special pigments
• Basics• Concepts• Examples
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Welding Seam Design• Basics• Concepts• Examples
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Globo welding Mask welding
Contour welding Simultaneous welding
Radial welding
Quasi-simultaneous welding
Welding Concepts• Basics• Concepts• Examples
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Contour welding
Contour Welding• Basics• Concepts• Examples
• Spot laser guided by X-Y Axis
• Highly Flexible
• Simple Weld Design
• Ideal for Quick Changeover
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Simultaneous Welding• Basics• Concepts• Examples
• Optic element used to form laser • One shot welding of weld seam • No relative movement • Short process times
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Quasi-simultaneous welding
Quasi-Simultaneous Welding
• Basics• Concepts• Examples
• Mirrors guide laser over weld seam • High flexibility
• Welding with displacement
• Gap bridging possible
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Mask welding
Mask Welding• Basics• Concepts• Examples
• Line Beam Laser and Mask
• Large areas and fine lines
• Complex contours and shapes • Protection of sensitive parts
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Radial welding
Radial Welding• Basics• Concepts• Examples
• Radial radiation • No rotation of part
• Short process times
• Ideal for welding axially symmetric / Cylindrical
• Push fit
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Globo welding
Globo Welding• Basics• Concepts• Examples
• Dynamic Clamping • Simple Joining Geometry
• Continuous Welding • Ideal for 3-dimensional and large parts
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Advantages of laser welding:
• high precision• high strength• minimal mechanical stress• minimal thermal stress• no damage to electronic
components• simple joining geometry• low tool wear• emission free• particulate free• no consumables
(adhesive/fasteners)• joining of elastomers
Laser Transmission Welding• Basics• Concepts• Examples
Contour welding
Globo welding
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Mask welding
Photo: Leister, by courtesy of IMM, Mainz (D)
Material:PC transparent / PC black
Specifications:• permeability • preservation of canal profile• canal width down to 100 µm• short processing time (3 seconds)
Micro pump
Requirement: welding of small structures (micro fluidics)
changeable width of welding seam
Method: line-beam-laser and structured mask
• Basics• Concepts• Examples
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Material:PC nature / PC black(both structured)
Specifications:• permeability• preservation of 3D channel profile• channel width down to 130 µm, • overall size 35 x 40 x 4 mm
Origin: FhG-ICT
Mixer-component
Mask welding
Requirement: welding of small structures (micro fluidics)
changeable width of welding seam
Method: line-beam-laser and structured mask
• Basics• Concepts• Examples
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Electronic Key
Material:PA laser transparent blackPA black
Specifications:• impermeability• no damage to electronics • no melting bulge
Photo: FHG - ILT
Contour welding
Requirement: extremely flexible with excellent welding results
Method: spot optic and axis system
• Basics• Concepts• Examples
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Electronic housing
Material:PC laser transparent blackPBT GF 30 black
Specifications:• permeability• No damage to electronic components
Photo: Leister, by courtesy of comp. Elektra, Schalkau (Germany)
Contour welding
Requirement: extremely flexible with excellent welding results
Method: spot optic and axis system
• Basics• Concepts• Examples
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Simultaneous welding
Optical Sensor
Material:PMMA transparent redPC black
Specifications:• no optical distortion• no contamination (particles)• pressure (> 12 bar)• permeability
Requirement: short-time processno relative motionmass production
Method: laser beam formed and guided byoptical elements
• Basics• Concepts• Examples
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Housing Flow-Sensor
Material:PMMA natural ABS grey
Specifications:• no contamination (particles)• preservation of electronics and
chips
Simultaneous welding
Requirement: short-time processno relative motionmass production
Method: laser beam formed and guided byoptical elements
• Basics• Concepts• Examples
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Display window
Material:PC nature PC black
Specifications:• permeability• no optical distortion
Simultaneous welding
Requirement: short-time processno relative motionmass production
Method: laser beam formed and guided byoptical elements
• Basics• Concepts• Examples
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Demo (Fair: K 2004)
Material:PC nature / PC black
Simultaneous welding
Requirement: short-time processno relative motionmass production
Method: laser beam formed and guided byoptical elements
• Basics• Concepts• Examples
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Camshaft sensor
Material:PA 66 GF 30 laser transparent blackPA 66 GF 30 black
Specifications:• permeability• no contamination (particles)• protection of electronic parts / sensors
Photo: Leister, by courtesy of comp. Delphi Automotive, Luxemburg
Radial welding
Requirement: welding of rotationally symmetrical components without relative motion
Method: two-mirror-scanner and conical mirror
• Basics• Concepts• Examples
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Globo welding
Automotive lighting
Material:PMMA transparent / ABS black
Specifications:• no thermal and mechanical stress
(Electronics)• 3D welding seam as design element• no static clamping device
Requirement: welding of 3D, large-area or endless components
flexible like contour welding
Method: spot optic combined with a dynamic clamping device
• Basics• Concepts• Examples
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Laser Welding Machines
NOVOLAS Basic NOVOLAS WS NOVOLAS micro
• Basics• Concepts• Examples• Laser
Systems
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LASERSYSTEMS
Distributed in the UK by:
For further details contact:Paul Anderson+44 1435 [email protected]
Adapted from a presentation by:Dipl. Ing. Oliver HinzProduct Manager