© Laserline GmbH, Germany 1 Plastic Welding Plastic Welding with Diode Lasers with Diode Lasers June 2005 June 2005 Laserline GmbH ! Muelheim-Kaerlich ! Germany www.laserline.de
© Laserline GmbH, Germany 1
Plastic WeldingPlastic Welding
with Diode Lasers with Diode Lasers
June 2005June 2005
Laserline GmbH ! Muelheim-Kaerlich ! Germany
www.laserline.de
© Laserline GmbH, Germany 2
Characteristics of Diode Laser Characteristics of Diode Laser
Direct diode laser on robot in production. Photo: Toyota
Advantages of Diode Lasers
1-step quick-welding
Flexible, any desired welding contour
Non-contact, fluff-free
Easily automated, high process stability
Low thermal and mechanical stress
“Top-Hat”-beam profile w/o intensity peaks
Applications
Gas-/fluid proof containers, electronic-
/sensor-housings, automotive parts, etc.
© Laserline GmbH, Germany 3
Plastic Welding with Diode Lasers Plastic Welding with Diode Lasers
Joining of Plastics with Diode Laser
" An Industrially Proven Process !
Content
Basics
Types of Welding Processes
Joining Techniques
Examples
Outlook
© Laserline GmbH, Germany 4
Welding of Plastic: PrincipleWelding of Plastic: Principle
Laser Beam
F
translucent
absorptive
Weld-Seam
F
Movement
Direction
Laser Beam Transmits Top Shell
Absorption in the Welding Zone
Bottom Shell
Melting of Both Parts by Heat Convection
Invisible Weld-Seam
No Damage to the Surface
© Laserline GmbH, Germany 5
Polymers for Plastic Welding
Thermoplastics (Amorphous or Partially
Crystalline) but not Duroplastics or Elastomeres
Overlapping Melting-Temperature
Comparable Melt Behaviour (Polarity etc.)
Transmission / Absorption Characteristics for
Laser Wavelength: One Transparent, One
Absorbing Layer
Mechanisms of Connection
Intermolecular Forces Between Molecule Chains
Mechanical Attachment by Macro-Molecules That
Diffuse from one Part to the Other
Welding of Plastic: BasicsWelding of Plastic: Basics
© Laserline GmbH, Germany 6
Parameters " Welding System
Laser: beam forming, wavelength, optical power,
spot size, energy distribution
Machine concept: laser, manipulating system
(positioning), cooling unit, electrics, other external
components
Parameters " Parts
Combination of thermoplastics (thermal, mechanical
and optical properties " additives!)
Type and positioning of weld seam, thickness, parts
design
Parameters " Process
Welding speed, cycle time, absorption of heat /
reaction time
Weld Results
Width of the seam
(HAZ)
Optical results
Resulting strength
Internal strains
Main ParametersMain Parameters
© Laserline GmbH, Germany 7
Welding of Plastic: BasicsWelding of Plastic: Basics
Source: VDI Kunststofftechnik/BASF
© Laserline GmbH, Germany 8
Welding of Plastic: BasicsWelding of Plastic: Basics
Source: VDI Kunststofftechnik/BASF
© Laserline GmbH, Germany 9
Welding of Plastic: BasicsWelding of Plastic: Basics
Laser
translucent
absorptive
Weld Joint
F
F
“Transmission welding”
Quality of weld depends on:
• Welding pressure
• Flatness of parts-surface
• Thickness of transparent welding
partner
© Laserline GmbH, Germany 10
„Setting Path“„Visible Notch“
F
F
Laser
Welding of Plastic: BasicsWelding of Plastic: Basics
Typical Part Design with Process Control by Welding Path
© Laserline GmbH, Germany 11
Plastic Welding: Typical DataPlastic Welding: Typical Data
10
100
1000
10 100 1000 10000
Power [W]
Be
am
qu
ali
ty [
mm
mra
d]
Hartlöten
Schneiden
Kunststoffs
chweißen
TiefschweißenLötenSchweißen
Hybridschweißen
Härten
Auftragsschweißen
10
100
1000
10 100 1000 10000
Power [W]
Be
am
qu
ali
ty [
mm
mra
d]
Plastic
Welding
Electronics housings
Laser
DioScan, Direct, Fiber-Coupled and
Multi-Diode Lasers
Power
50 W to 800 W
Beam quality
< 150 mm mrad
Spot dimensions
0.5 to 5 mm
Material
- Thermoplaste
- Thermoplastische Elastomere (TPE)
© Laserline GmbH, Germany 12
Diode Laser Types for Plastic WeldingDiode Laser Types for Plastic Welding
Fiber-coupled diode laser LDM
Multi diode laser system (100 diode laser sources)
DioScan F
Direct diode laser, LDL 40
© Laserline GmbH, Germany 13
DioScan: beam scanner with PC or stand-alone control,
scanner software and integration for plastic welding
Optics with different beam dimensions and working distances
1-inch or 2-inch optics
Ring focus optics for simultaneous welding of circular seams
Circumferential weld optics for welding of tubes
Pyrometer and CCD camera for process monitoring
PlasticPlastic WeldingWelding: : OptionsOptions
© Laserline GmbH, Germany 14
Variants of Welding ProcessesVariants of Welding Processes
I. Quasi-Simultaneous Welding (QS):
Uniform, step-by-step heating of the
weld zone
Rotation symmetric parts or any
desired 2D-contour
II. Contour Welding:
One-step-welding process
Any desired geometry, 3D contour
© Laserline GmbH, Germany 15
Special Variants ISpecial Variants I
Multi-Laser-System:
Rotation symmetric parts
Uniform, simultaneous heating of
different weld zones
Shortest cycle time
Cost reduction due to less process
stations
© Laserline GmbH, Germany 16
Special Variants IISpecial Variants II
Simultaneous Welding:
Uniform, simultaneous Heating of
the Weld Zone
No internal strains, any part
geometry
Reduced cycle time
Low flexibility, high complexity
© Laserline GmbH, Germany 17
Special Variants IIISpecial Variants III
Special focusing optics for circular focus geometry
„AXICON“
Laser-light-cable
Laser beam
Rotation symmetric part
Parabolic mirror
Circular focusing optics
Collimating optics
Scheme: Special Optics
© Laserline GmbH, Germany 18
Systems ASystems Advantagesdvantages
Spot Welds
Contour Welds
Multi-Spot Welds
Step Welds
Weld Geometry \ Laser Direct & Fiber-Coupled Scan-System Multi Diode
(QS) (simultaneous)
© Laserline GmbH, Germany 19
I. System Concept: Multi-LaserI. System Concept: Multi-Laser
100-Laser-System
Multi-Laser-System
Redundant system
Shortest cycle time
Applications
• Structures
• Foils
• Rotation symmetrical partsTwin-Laser-System
© Laserline GmbH, Germany 20
II. System Concept: QS-WeldingII. System Concept: QS-Welding
Part holder
DioScan Circular table
Laser safety feature
DioScan
Simple manipulation system
Laser safety box
Short cycle time
Application
Sensors, electronic housings,
etc.
© Laserline GmbH, Germany 21
Ultrasonic• 1-Step-Process
• Mechanical Force Transmission
• US-Frequency in Weld Zone
• All Thermoplastics
Glueing• Multi-Step-Process
• Glue Application through Nozzles
• Most Plastics
Heat Plate
• 1-Step-Process
• Global Heating through Heat Plates
• All Thermoplastics
Joining Techniques - ComparisonJoining Techniques - Comparison
Laser• 1-Step-Process
• No Touch
• IR-Radiation in Weld Zone
• All Thermoplastics (optically suited)
Vibration• 1-Step-Process
• Mechanical Force Transmission
• Vibration Forces in Weld Zone
• All Thermoplastics
© Laserline GmbH, Germany 22
0
50
100
Availability
Flexibility
Joint-qualityGap-bridging
Part damage
Laser
US
VIB
Gluing
Joining Techniques - ComparisonJoining Techniques - Comparison
Diode Laser
• Highest welding quality (visible joints, fluff free)
• Highly flexible (robot, axis-system,
quasi-simultaneous welding)
• Availability 99.5 %
• Gap-bridging
• Wear-resistant tool
Scan system
Direct diode
laser
© Laserline GmbH, Germany 23
Requirements from IndustryRequirements from Industry
Requirements• Failed parts 0 ppm
• Gap bridging
• Gas proof
• No damage to the part
• No fluff in weld
• Any desired contour
• Sensitive electronic parts
Characteristics• Process control
• Check of melting path
• Endless weld-seams
• Non-contact
• No vibrations
• Maximum flexibility
• Local heat input
Vibration
Gluing
Laser
Ultrasonic
Heat Plate
© Laserline GmbH, Germany 24
Weld Seam Geometry YAG vs. Diode LaserWeld Seam Geometry YAG vs. Diode Laser
--++Large area weldsPlastic layers, plate material, foils
-+++< 1.5 mmLarge housings, broad area connections,contour welding
+++++0.25 ...1.5 mmSensors, small housings, welding with settingpath
++++< 0.25 mm.!-Structures, etc.
Nd:YAGDiodeWeld seam dimensions. Advantages anddisadvantages of the different systems
Diode Laser
Top-hat beam profile "
Homogeneous weld over
entire width of weld seam
Good weld seam control
Ideal for welds > 0.25 mm
width and larger areas
Nd:YAG Laser
Gauß beam profile:
High central intensity limits
max. power
Higher risk of parts damage
Less homogeneous weld
Ideal for micro structures
< 0.25 mm width
w = weld zone
ww
Diode Laser Nd:YAG Laser
© Laserline GmbH, Germany 25
Influence of Power on ProductivityInfluence of Power on Productivity
influence of laser power, material: PA6,
weld seam length: 250mm
0
5
10
15
20
25
50 150 250 350
laser power [W]
tota
l ti
me f
or
weld
[s]
0
1
2
3
4
5
sp
eed
[m
/s]
Potenziell (Ges.-Zeit [s])
Polynomisch (v [m/s])
time for weld
scan speed
Quasi simultaneous welding
Almost constant path
energy without damage
to components
Higher power and scan
speed result in reduced
welding time
High flexibility AND
high productivity
© Laserline GmbH, Germany 26
Laser control by scan software
Graphical view of settings
User-/ Operator surface
Special mode for easy operation
(e. g. operator mode for 3-shift
production)
Contour flexibility, import of dxf, wmf,
bmp, plt, ...
Scan SoftwareScan Software
© Laserline GmbH, Germany 27
Prozess Prozess MonitoringMonitoring
SoftwareThermal OpticalMechanical Visual
Setting path
sensor
Back reflection
diagnoctics
Pyrometer Frame-Grabber CCD-Camera
Alignment
beam
© Laserline GmbH, Germany 28
ExamplesExamples: Automotive : Automotive IndustryIndustry
Schaltbox
Air Flow Sensor
Car Key
© Laserline GmbH, Germany 29
ExamplesExamples: Automotive: Automotive Industry Industry
Electronic Housings
Automatic Gear Box
© Laserline GmbH, Germany 30
Plastic Welding: ExamplesPlastic Welding: Examples
Mats from plastic material
Liquid pouring device
Invisible weld seam in PMMA
Weld of foam on plastics
© Laserline GmbH, Germany 31
Integration in a system with round switch tablePhoto
: Laserq
uip
ment
Example: Magnetic Sensor Example: Magnetic Sensor
Tyco Electronics AMP GmbH
Welding seam
© Laserline GmbH, Germany 32
LDL 40-100 - Direct Diode Laser
Contour Welding
Opaque Material
Example: Movement SensorExample: Movement Sensor
Source: Laserquipment
© Laserline GmbH, Germany 33
Example: Hydraulic TankExample: Hydraulic Tank
Source: branson
Welding of hydraulic tanks
DioScan 200
Result:
Excellent welding seam
Single step process
Highest process-stability
Non-contact process
No fluff development
© Laserline GmbH, Germany 34
ExampleExample: : Ostomy BagsOstomy Bags
LDF 600-300
Fiber-Coupled Diode Laser
Medical Industry
Contour welding of concentric
Circles
Soft-to-soft welding
© Laserline GmbH, Germany 35
Medical Industry
Contour welding of
transparent material
“Clear weld” (1)
Black absorbing foil (2)
Example: Filter ElementExample: Filter Element
Source: Leister
(1)
(2)
© Laserline GmbH, Germany 36
Reference Customers (selection)Reference Customers (selection)
Others
- Boeing
- Colbond
- Erlas
- Philips
- Thyssen
- TRW
Metal Welding
Plastic Welding
Pump-Module for Fiber-Laser
Automotive
- Bosch
- Bremi
- Daimler Chrysler
- Geigertechnik
- Grau
- Mendiguren
- Siemens VDO
- VAW
Metal Welding
Plastic Welding
Sensors
Electrical-MechanicalComponents
Valves
Housings
© Laserline GmbH, Germany 37
OutlookOutlook
Plastic Welding with Diode Laser
• Highest Quality-Requirement for
Joining Techniques in Automotive
Industry
• Easily Integrated in Full-Automation
Systems
• Customers-Specific Solutions