Understanding the Basics of Electrocoat. Kelly Moore Development Chemist

Transcription

1 Understanding the Basics of Electrocoat Kelly Moore Development Chemist

2 Overview Why and When to Use Electrocoat How Does Electrocoat Work? Selecting the Right Electrocoat Technology The Future of Electrocoat 2

3 Why and When to Use Electrocoat 3

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10 Why Use Electrocoat? Economical & Efficient Environmentally Conscientious Excellent Performance Some Disadvantages High transfer efficiency Precise film build control No or low VOC HAPs-free products available Controlled uniform film thickness Improved aesthetics Capital expenditure Color flexibility (multiple colors) 100% coverage of complex parts Coats recessed areas Automated system: low maintenance and minimal labor Dense racking of parts Non-uniform line loading Heavy metal-free products Minimal waste discharge Reduced fire hazards Reduced exposure of workers to hazardous materials No runs, drips, or sags 100% coverage One or two coat applications for optimal performance Epoxy-based for corrosion, acrylicbased for durability Substrate must be conductive Bake required (thermoset) 1 0

11 Selecting the Right Coating System Performance Requirements & Specifications Appearance Physical properties & durability (adhesion, flexibility, chip resistance, corrosion resistance, UV resistance, etc.) Substrate & Part Configuration Heat limitations Part complexity and size Environmental Factors Economics Applied Cost Per Square Foot Air emissions (VOC/HAPs) Waste considerations Transfer efficiency Labor/time requirements Number of parts to process 1 1

12 Selecting the Right Coating System Liquid Powder E-Coat Colors / Color Changes Best Better Limited Heat Limitations Best Limited Limited Environmental Impact High Lowest Low Transfer Efficiency Limited Better Best Manual Labor Automated Labor High Good High Good N/A Best # Parts Processed Limited Limited Best 1 2

13 How Does Electrocoat Work? 1 3

14 What is Electrocoat? Method of applying a coating which uses electrical current to deposit aqueous dispersed resins and pigments onto a conductive substrate Highly efficient and automated process Precipitation of paint particles at an electrode Paint film thickness is regulated by voltage 1 4

15 The Deposition Sequence Voltage is applied and current flows between electrodes Water decomposes at the electrodes Paint particles move to the oppositely charged electrode Paint particles precipitate Paint particles become tightly packed (insulated) Deposition stops automatically The insulating ability of the deposited wet film is what allows the electrocoat process to coat interior recesses and cavities throwpower 1 5

16 Electrocoat Works Like a Magnet Cathodic Anodic Metal Substrate Cathode Coating film deposits with FE ++ Paint Particles Anode Coating film deposits without FE

17 Electrocoat Process: The E-Coat Bath Water-Soluble Bath Blend Pigment 1-10% De-Ionized Water 80-90% Resins 10-15% Solvent / Additives 1-5% 1 7

18 Electrocoat Process: Sample Process Layout Particle Filter Ultrafilter Racking Flash (Pre-bake) Oven Pumps 1 8 Power Supply / Process Control Sample Tank Stages Cleaning Pretreatment Rinsing E-Coat Permeate Rinsing DI Rinsing

19 Electrocoat Process: Pretreatment Pretreatment Rinse Without Pretreatment With Pretreatment 1 9 Cleans the metal and prepares it for coating Common to all application technologies Can be spray or immersion applied Major contributor to system performance Type and number of stages dictated by performance requirements

20 Electrocoat Process: The Electrocoat Tank Filter removes dirt particles Electrocoat Permeate Rinse Circulation pumps and eductors to ensure paint mixing uniformity 2 0 Rectifier provides DC electrical charge; heat exchanger controls bath temperature Ultrafilter produces permeate for rinsing and allow for recovery of paint solids Electrocoat tanks may hold up to 100,000 gallon

21 Electrocoat Process: The Post Rinse & Bake Oven 1-3 counter-flowing rinses remove excess paint solids Smoother finish appearance Higher operating efficiency 2 1 Used to cure and crosslink the paint film Bake varies from 180º F - 375º F depending on electrocoat type Usually require at least minutes metal temperature for full cure

22 Equipment Design and Operation: Selection Criteria Capital Expense Floor Space Productivity Maintenance Racking of Parts Process Flexibility 2 2

23 Equipment Design and Operation: Monorail Systems Highest productivity Lowest maintenance Biggest footprint Highest capital expense 2 3

24 Equipment Design and Operation: Programmable Hoist System Highest flexibility Highest maintenance Medium to low capital expense Lowest productivity Smallest floor space 2 4

25 Equipment Design and Operation: Square Transfer System Lowest capital expense Smallest floor space Medium to low maintenance Medium to high productivity Medium flexibility 2 5

26 2 6 Equipment Design and Operation: Racking vs. Bulk Electrocoat Racking Part configuration / design Size / number / density of parts Touch points on parts Maintenance Contact points Bulk Dip-drain / sip-spin Shift parts to coat touch points Fasteners, other small parts

27 Equipment Design and Operation: Relative Comparison of Systems Programmable Hoist Indexing System Square Transfer Monorail Productivity Lowest Medium to High Highest Maintenance Highest Medium to Low Lowest Capital Expense Medium to Low Lowest Highest Floor Space Small Smallest Highest Process Flexibility Highest Medium Lowest 2 7

28 Selecting the Right Electrocoat Technology 2 8

29 Electrocoat Types Paint particles positive Coated parts negative Advantages Less iron incorporated into the film Formulated for maximum corrosion resistance and exterior durability Paint particles negative Coated parts positive Advantages Economical systems for interior or moderate exterior environments Low cure temperatures Low VOC 2 9

30 Electrocoat Technologies Advantages Corrosion protection Chemical resistance "Tough" film Disadvantages Poor U.V. resistance (chalks) Poor color stability (cationic) Advantages Good U.V. resistance Gloss retention Good color control Disadvantages Less corrosion protection 3 0

31 Electrocoat Technologies Benchmark for corrosion & chemical resistance Automotive parts, car bodies, heavy duty trucks, fasteners Low-bake applications Heavy-duty castings, compressors High performance, one-coat applications UV durability & detergent resistance Color control Color & gloss control for interior products Metal office furniture, air diffusers, range hoods, tool boxes 3 1

32 Electrocoat Technologies Excellent corrosion resistance, especially on sharp edges Lead-free HAPs-free Low VOC 3 2 Agriculture & construction Automotive parts Compressors Computer parts Control arms Engine cradles Heavy duty trucks Marine engines Spring clips Suspension components Switchgear Torsion bars Transformers Truck frames

33 Electrocoat Technologies Low cure: º F cure capability Fully thermoset Hardness/corrosion resistance similar to higher cure coatings Lead and chrome-free Good throwpower More iron in film, which limits performance Agricultural implements Assemblies fork lifts Compressors Concrete reinforcements Construction equipment Engines & motors Seat tracks Heavy duty castings Military aircraft Pipe Plated plastics Structural steel Aluminum substrates Galvanized substrates 3 3

34 Electrocoat Technologies High performance with both high- and low-gloss capability Color control and can be formulated as a clear Can be formulated for optimum corrosion or durability HAPS compliant Topcoat-able (should be tested) Agricultural implements Air conditioners Aluminum extrusions Appliances Brass, plated substrates Heavy duty equipment Lawn & garden Refrigeration Switchgear Transformers Welding equipment Wheels 3 4

35 Electrocoat Technologies Excellent appearance, gloss, and color control Interior & mild exterior use Reduced emissions No/low solvent additions No heavy metals More iron in film, which limits performance Air conditioners Air diffusers Furnaces Hangers Metal office furniture Metal strapping Range hoods Toolboxes Wire screen 3 5

36 Electrocoat Applications Electrocoat is the final finish Two electrocoat layers for high performance Electrocoat + a liquid or powder topcoat produces exceptional performance properties 3 6

37 Electrocoat Applications Cathodic epoxy basecoat ensures excellent corrosion protection Cathodic acrylic primer-surfacer provides an exterior durable finish and cost-effective topcoat Corrosion protection, chip resistance, UV durability No heavy metals Agricultural implements Aluminum trim Condensing coils Generator housings Marine engines Transformers 3 7

38 Electrocoat Applications Cathodic epoxy basecoat ensures excellent corrosion protection Liquid or powder topcoat allows for combination of corrosion resistance and desirable appearance Automotive High-end appliances Sports and recreation 3 8

39 Summary Corrosion Resistance Auto Parts Low Cure Coat Hangers Shopping Carts UV Resistance Washers & Dryers Lawn & Garden Agricultural Equipment Decorative Consumer Electronics Jewelry Severe Environments Generators Transformers 3 9 Performance + Appearance Automotive Appliances Sports and Recreation

40 Questions? 4 0

41 Thank You Kelly Moore Development Chemist PPG Industrial Coatings