in-mold coatings for smc, thermoplastics and low temperature
TRANSCRIPT
In-mold coatings for SMC, thermoplastics and low
temperature thermoset composite processes European Coatings Conference
Functional Coatings
Berlin, Germany
5-6June2012
Elliott J. Straus
OMNOVA Solutions Inc.
2990 Gilchrist Rd.
Akron, Ohio 44305
USA
Presentation Outline
• Part I IMC functionality and
application to SMC
• Part II IMC application to
thermoplastics and low
temperature composites
• Part III
Summary & questions
In-Mold Coatings Technology – Compression Molding
• In-Mold Coatings improve the
quality of SMC parts
• Growing use of IMC as a primer
for basecoat paint
• Economic incentive to replace paint
operations with conductive and color
matched IMC’s
• Next logical step to use IMC itself
as an appearance coating
GenGlaze® and Stylecoat® In-Mold Coatings
EC-610, EC-2447, EC-2500
(Conductive Black)
EC-800
(Conductive Gray
20 Gray
(Non-Conductive)
50 Gray
(Non-Conductive) Stylecoat® Red
(Appearance IMC)
Stylecoat® Green
(Appearance IMC)
SMC Manufacturing Process
Film
Film
Wind up Roll
Compaction Rolls
Resin
Resin
Chopper
Chopped Fibers
Cut and weigh
SMC charge
Charge
the Mold
SMC
Filling
SMC
Curing
IMC
Injection
IMC
Curing
Filling
Open the Mold Remove the
Molded Part
SMC Cycle IMC Cycle Pre-Molding Post-Molding
Unit Operations in Compression Molding
Sheet Molding Compound with IMC
IMC Process for Compression Molded SMC
Stationary Mold Half
Moveable Mold Half
Stationary Mold Half
Moveable Mold Half
Stationary Mold Half
Moveable Mold Half
IMC
SMC
In-Mold Coatings Technology – Compression Molding
IMC Key Performance Features
• One component design with catalysis by the addition of peroxide
initiator away from the press
• Excellent rate of property development at typical molding temperatures
• High conductivity in primer IMC at coating thicknesses as low as 0.5
mil (12.7 microns)
• Excellent strength, abrasion and scuff resistance for ease of handling
and sanding in subsequent processing
• Appearance UV resistant clear/pigmented coating available
• Excellent substrate adhesion
• 100% Solids
In-Mold Coatings Technology – SMC Compression Molding
• Substrate porosity filling and surface sealer
• Provides solvent/moisture barrier
• Provides a uniform and improved surface
– reduces or eliminates fiber read through
– no orange peel
– levels low and high spots
– enhances DOI
• Facilitates good primer/paint adhesion
• Provides the option of a “primerless” scenario
• Product available with specialized functions
– conductivity
– color matched primer & clear/color topcoat
– Soft touch
IMC Functionality
IMC Application Equipment
Common SMC Parts Utilizing GenGlaze® IMC
Storage
Door Transition
Panel
A-Pillar
D-Pillar
Hood
Sunvisor Cab Door
Fender
Rooftop
Gravelometer 0°F
GM9508P
Cross-Hatch
Ford Bl 106-01
Tape Adhesion
GM9071P
Brittleness
GM9506P
CDL4.0 (no chipping)
MT2C after
10 Day Water Immersion
Ford ESB-M2P124-A1
MT1A After
E-Coat
1 Hour @ 400°F
IMC performance and Overall part quality Acceptable part
• Summer Months
• Storage conditions
• Humidity effect on
SMC/IMC
• Temperature Control
• Cooling bands on
drums
• Housekeeping
• Monitoring press operation
• Force
• Velocity
• parallelism
• Phase timing
• IMC open/reclose speed
• IMC open height
• IMC booking
• Shot size adjustment
• SMC/IMC cure times
• IMC film thickness
Selection of Process parameters
• SMC charge placement
• SMC molding profile
• IMC molding profile
• IMC shot size based on part surface area
• Rationale for adjustments
•Troubleshooting guide
IMC Meter
• Properly sized
• Check valve leak
• (2) Synchronized
• Injection rate
Press
• Force profile
• Velocity profile
• Parallelism
• Machine time
• Operational performance
Mold
• Position in Press Bed
• Temperature control
• Shear edge condition
• Nozzle placement/Flush
• Condition of mold in general
• Vacuum effectiveness & process
• Part lifting
IMC
• Catalyst level
• Age/History
• Temperature
• Shot volume
• Storage
• Mixing schedule
• SMC pattern cut
• SMC pattern placement
• Good molding practices
•Cleaning
•Discipline
• Training status
• Shift change communication
Environment Measurement Method
Machine Equipment Material Human
IMC Process Troubleshooting
SMC
• Viscosity consistency
• Sheet weight
• Cure behavior
• Release
•Enhances DOI
•No orange peel
•Provides a solvent/moisture barrier
•Abrasion and scuff resistance
•Provides a conductive surface for electrostatic painting
•100% solids (zero VOC’s)
Key Points to Remember
In-Mold Coatings for SMC
Presentation Outline
• Part I IMC functionality and
application to SMC
• Part II IMC application to
thermoplastics and low
temperature composites
• Part III
Summary & questions
Injection
Molding Primer Top Coat
Emission Emission Current Process
Thermoplastic Pellets Finished Product
Injection
Molding Top Coat
Emission
IMC
Short term solution (no primer)
Thermoplastic Pellets Finished Product
Injection
Molding
Long term solution (no primer and paint)
Thermoplastic Pellets Finished Product
IMC for Thermoplastic
Thermoplastic
Injection
Packing
Solidification by Cooling
Packing
Coating Curing Reaction
IMC
Filling
Eject Part
IMC for Thermoplastic in Injection Molding
Injection Molding with IMC process
Key Issues in IMC Process
• Nozzle location
– 100% coverage is achieved
– Location is cosmetically acceptable
– Easy maintenance
– Defects like trapped air are minimized
• Coating Injection Pressure
– Should not exceed the clamping pressure of the Injection Molding Machine to avoid leakage
– Mold design to prevent IMC leakage from parting line
• Coating material curing conditions
– Adhesion and compatibility with particular thermoplastic molding conditions and mold thermal design
– Peroxide selection and amount yields adequate pot life of IMC
Summary of low temperature IMC primer @ 100ºF (38ºC) potlife
Catalyzed and placed in Oven @530
Hour of Day
% peroxides 630 730 930 1000 1030 1100 1115 1315
1.75/1.0 ok ok gel Solid Solid Solid Solid Solid
1.75/0.75 ok ok ok Solid Solid Solid Solid Solid
1.75/0.5 ok ok ok gel Solid Solid Solid Solid
1.75/0.25 ok ok ok ok ok ok gel Solid
1.75/0.1 ok ok ok ok ok ok ok gel
1 hour 2 hours 4 hours 4.5 hours 5 hours 5.5 hours 5.75 hours 8.25 hours
IMC for SMC and Thermoplastic – Tooling Difference
shear edge acts as a seal
SMC mold
Opening will lead to
coating leakage
Thermoplastic
mold
The Thinner Groove of the Valve Cover
Study on the IMC Filling in a Valve Cover Part
IMC Injection Port
Comparisons of the Short Shots and Numerical Predictions
IMC Nozzle Experimental Mold
Predicting Fill Patterns
• IMC Fill simulation tool developed based on Hele-Shaw model to predict Fill patterns
32
Pressure Comparison for PCABS
(Full Shot)
Comparison of the Short Shots and Numerical Predictions
Heavy Truck Bumper
• The Priamus data collection device used for determining the optimum injection process and in place to monitor the IMC injection pressure from the IMC injection device for future trial/production process control.
• IMC 13in3 shot volume target
•Thermoplastic PC/ABS
•Cincinnati Milacron 4500 Ton Press
•dual injection cart with 9000psi peak injection pressure
capability
•Mold temperature 180°F target (actual range 165°-180°F)
•PRIAMUS data collection device used to optimize process
Presentation Outline
• Part I IMC functionality and
application to SMC
• Part II IMC application to
thermoplastics and low
temperature composites
• Part III
Summary & questions
Summary of Applications Available IMC for various applications
IMC Chemistry Substrates Temperature Application Functionality
GenGlaze® Primers
epoxy acrylate SMC BMC LCM
150ºC
Automotive
Heavy Truck
Marine
Conductive primers
non-conductive primers
epoxy/urethane
acrylate
Stylecoat® Topcoats urethane acrylate SMC BMC LCM 150ºC Residential
Topcoat
NSP® Soft Touch urethane di-acrylate SMC BMC LCM 150ºC (80ºC)
Food Service
Specialty non-slip surface
GenGlaze®/Stylecoat® with low temp peroxide package
urethane acrylate PC/ABS PET
DCPD RTM TPO 80ºC
Automotive
Heavy Truck
Agricultural
Primer or Topcoat
Development or
Approval process
Commercialized
Summary
• The absence of solvents in IMC makes it an environmentally preferred “green” process.
• Since the coatings are incorporated during the molding process instead of being applied separately they reduce the number of surface finishing steps and cost in manufacturing while being environmentally friendly.
• A newly developed family of primers and topcoats for low temperature processes allow for a broader application potential.