Slide 24 Important

8/3/2019 Slide 24 Important

1/37

Laserline GmbH, Germany 1

Plastic WeldingPlastic Welding

with Diode Laserswith Diode LasersJune 2005June 2005

Laserline GmbH ! Muelheim-Kaerlich ! Germanywww.laserline.de


2/37


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.


3/37


Plastic Welding with Diode LasersPlastic Welding with Diode Lasers

Joining of Plastics with Diode Laser " An Industrially Proven Process !

Content

Basics

Types of Welding Processes

Joining Techniques

Examples

Outlook


4/37


Welding of Plastic: PrincipleWelding of Plastic: Principle

Laser Beam

F

translucent

absorptive

Weld-Seam

F

MovementDirection

Laser Beam Transmits Top Shell

Absorption in the Welding ZoneBottom Shell

Melting of Both Parts by Heat Convection

Invisible Weld-Seam

No Damage to the Surface


5/37


Polymers for Plastic Welding

Thermoplastics (Amorphous or PartiallyCrystalline) but not Duroplastics or Elastomeres

Overlapping Melting-Temperature

Comparable Melt Behaviour (Polarity etc.)

Transmission / Absorption Characteristics for Laser Wavelength: One Transparent, OneAbsorbing Layer

Mechanisms of Connection

Intermolecular Forces Between Molecule ChainsMechanical Attachment by Macro-Molecules ThatDiffuse from one Part to the Other

Welding of Plastic: BasicsWelding of Plastic: Basics


6/37


Parameters " Welding System

Laser: beam forming, wavelength, optical power,spot size, energy distribution

Machine concept: laser, manipulating system(positioning), cooling unit, electrics, other externalcomponents

Parameters " Parts

Combination of thermoplastics (thermal, mechanicaland optical properties " additives!)

Type and positioning of weld seam, thickness, partsdesign

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


7/37



Source: VDI Kunststofftechnik/BASF


8/37



Source: VDI Kunststofftechnik/BASF


9/37



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


10/37


Setting Path Visible Notch

F

F

Laser


Typical Part Design with Process Control by Welding Path


11/37


Plastic Welding: Typical DataPlastic Welding: Typical Data

10

100

1000

10 100 1000 10000

Power [W]

B e a m

q u a

l i t y [ m m

m r a

d ]

H a r t l t e n

S c h n e i d e n

K u n s t s t

o f f s c h w

e i e n

T i e f s c h

w e i e n

L t e n

S c h w e i e n

H y b r i d s c h w e

i e n

H r t e

n

A u f t r a g s s

c h w e i e n

10

100

1000

10 100 1000 10000

Power [W]

B e a m

q u a

l i t y [ m m

m r a

d ]

P l a s t i c

W e l d i n g

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)


12/37


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


13/37


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


14/37


Variants of Welding ProcessesVariants of Welding Processes

I. Quasi-Simultaneous Welding (QS):

Uniform, step-by-step heating of the

weld zoneRotation symmetric parts or anydesired 2D-contour

II. Contour Welding:

One-step-welding processAny desired geometry, 3D contour


15/37


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 processstations


16/37


Special Variants IISpecial Variants II

Simultaneous Welding:

Uniform, simultaneous Heating of the Weld Zone

No internal strains, any partgeometry

Reduced cycle time

Low flexibility, high complexity


17/37


Special Variants IIISpecial Variants III

Special focusing optics for circular focus geometryAXICON

Laser-light-cable

Laser beam

Rotation symmetric part

Parabolic mirror

Circular focusing optics

Collimating optics

Scheme: Special Optics


18/37


Systems ASystems A dvantagesdvantages

Spot Welds

Contour Welds

Multi-Spot Welds

Step Welds

Weld Geometry \ Laser Direct & Fiber-Coupled Scan-System Multi Diode(QS) (simultaneous)


19/37


I. System Concept: Multi-Laser I. System Concept: Multi-Laser

100-Laser-System

Multi-Laser-System

Redundant system

Shortest cycle time

Applications

Structures

Foils Rotation symmetrical parts

Twin-Laser-System


20/37


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.


21/37


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


22/37


0

50

100

Availability

Flexibility

Joint-qualityGap-bridging

Part damage

Laser

USVIB

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 diodelaser


23/37


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


24/37


Weld Seam Geometry YAG vs. Diode Laser Weld 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 seamGood weld seam controlIdeal for welds > 0.25 mmwidth and larger areas

Nd:YAG Laser Gau beam profile:High central intensity limitsmax. power Higher risk of parts damageLess homogeneous weldIdeal for micro structures< 0.25 mm width

w = weld zone

ww

Diode Laser Nd:YAG Laser


25/37


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]

t o t a l t i m e

f o r w e

l d [ s ]

0

1

2

3

4

5

s p e e

d [ m / s ]

Potenziell (Ges.-Zeit [s])

Polynomisch (v [m/s])

time for weld

scan speed

Quasi simultaneous weldingAlmost constant pathenergy without damageto componentsHigher power and scanspeed result in reducedwelding time

High flexibility ANDhigh productivity


26/37


Laser control by scan software

Graphical view of settings

User-/ Operator surface

Special mode for easy operation(e. g. operator mode for 3-shiftproduction)

Contour flexibility, import of dxf, wmf,bmp, plt, ...

Scan SoftwareScan Software


27/37


ProzessProzess MonitoringMonitoring

SoftwareThermal OpticalMechanical Visual

Setting pathsensor

Back reflectiondiagnoctics

Pyrometer Frame-Grabber CCD-CameraAlignment

beam


28/37


ExamplesExamples : Automotive: Automotive IndustryIndustry

Schaltbox

Air Flow Sensor

Car Key


29/37


ExamplesExamples : Automotive: Automotive IndustryIndustry

Electronic Housings

Automatic Gear Box


30/37


Plastic Welding: ExamplesPlastic Welding: Examples

Mats from plastic material

Liquid pouring device

Invisible weld seam in PMMA

Weld of foam on plastics


31/37


Integration in a system with round switch table P h o

t o :

L a s e r q u

i p m e n

t

Example: Magnetic Sensor Example: Magnetic Sensor

Tyco Electronics AMP GmbH

Welding seam


32/37


LDL 40-100 - Direct Diode Laser

Contour Welding

Opaque Material

Example: Movement Sensor Example: Movement Sensor

Source: Laserquipment


33/37


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


34/37


ExampleExample :: Ostomy BagsOstomy Bags

LDF 600-300Fiber-Coupled Diode Laser

Medical IndustryContour welding of concentricCircles

Soft-to-soft welding


35/37


Medical Industry

Contour welding of transparent material

Clear weld (1)

Black absorbing foil (2)

Example: Filter ElementExample: Filter Element

Source: Leister

(1)

(2)


36/37


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


37/37


OutlookOutlook

Plastic Welding with Diode Laser

Highest Quality-Requirement for Joining Techniques in AutomotiveIndustry

Easily Integrated in Full-AutomationSystems

Customers-Specific Solutions

Documents

Slide 24 Important