Pollution Prevention in the Paints and Coatings Industry

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MB

205

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National Risk Management Research Laboratory

2000

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Contents

SECTION 1

Chapter 1

Chapter 2

foreword iii

Abstract . iv

Figures . xiv

Tables . xvi

ConversionFactors xviii

Acknowledgments . xix

Overview 1

Introduction . 2

1.1 Pollution Prevention in the Paints and Coatings Industry2

1.2 The Audience for This Document. 2

1.3 The Organization of This Document. 2

Overview of Paints and Coatings Operations . 4

Introduction . 4

Operations for Miscellaneous Metal Workpieces. 4

2.2.1 Priming Only . 4

2.2.2 Priming and Topcoating5

2.2.3 Surface Preparation . 7

2.2.4 Application of Paint Coating Systems., 9

2.2.5 Abatement Equipment. 9

Operations for the Automotive Industry 10

2.3.1 ProcessOverview 10

2.3.2 Paint Coating Systems and Application Processes 10

2.3.3 Abatement Equipment. 12

Operations for Plastic Parts . 12

2.4.1 Surface Preparation. 12

2.4.2 Coatings Systems 12

2.4.3 Application Equipment . 12

2.4.4 Abatement Equipment . 13

Custom Coating Operations . 13

2.6 References 13

2.7 Additional Reading 13

SECTION 2 Pretreatment Factors 15

Chapter 3 Adhesion as a Critical Factor 16

3.1 introduction 16

3.1 .l Pollution Prevention Considerations 16

3.2 Corrosion of Metals and Alloys. 16

3.2.1 Basics of the Corrosion Process, 16

3.2.2 The Science Behind Corrosion 17

3.2.3 Fundamentals of Corrosion Prevention. 18

3.3 Preventing Corrosion by Ensuring Proper Adhesion 18

3.3.1 Mechanismsof Adhesion . 18

3.3.2 The importance of Proper Wetting . 18

3.3.3 The Role of Surface Contaminants . 19

3.4 Adhesion Considerations Specific to Plastic Substrates . 21

3.5 References 21

Chapter 4 Considerations Regarding Vendor-Supplied Materials23

4.1 Introduction 23

4.1 .l Pollution Prevention Considerations 23

4.1.2 Decision-Making Criteria . 23

4.2 Raw Materials. 23

4.2.1 Protective Coatings and Treatments23

4.2.2 Storage . 24

4.3 Componentsand Pans . 24

4.3.1 Protective Coatings and Primers. 24

4.3.2 Storage . 25

4.4 Just-in-Time Delivery . 25

4.5 References 25

Chapter 5 Surface Degreasing: Alternatives to Conventional Solvent-Based Methods26

5.1 introduction 26

5.1 .l Pollution Prevention Considerations 26

5.1.2 Decision-Making Criteria . 26

5.2 Basic Practices and Regulatory Considerations . 26

5.2.1 Typical Oils and Grime on Substrates 26

5.2.2 Basic Cleaning Approaches. 28

5.2.3 Selecting a Cleaning Approach28

5.2.4 Regulatory Overview 29

5.3 Solvent-Based Methods 29

5.3.1 Vapor-Solvent Degreasing 29

5.3.2 Degreasing With Liquid Solvent (Cold Cleaning and Solvent Wiping)32

5.4 Aqueous Methods. 34

5.4.1 Aqueous Degreasing 34

5.4.2 Semi-aqueous Degreasing 37

5.5 CaseExamples . 38

5.5.1 Frame Manufacturer . 38

5.5.2 Military Contractor 39

5.5.3 Lift Truck Manufacturer 39

5.6 References 40

Chapter 6 Phbsphating Metal Surfaces: Process Efficiency and Waste Minimization. 41

6.1 Introduction 41

6.1 .I Pollution Prevention Considerations 41

6.1.2 Decision-Making Criteria . 41

6.2 Process Basics and Best Management Practices41

6.2.1 Introduction 41

6.2.2 Coating Quality and Basic Parameters 44

6.2.3 Best Management Practices 45

6.3 PhosphatingMethods: . 45

6.3.1 Iron P hosphating . 45

6.3.2 Zinc Phosphating . 47

6.3.3 Wash Primers as an Alternative to Phosphating. 48

6.4 Waste Minimization and Treatment . 48

6.4.1 Minimization . 48

6.4.2 Treatment . 49

6.5 Additional Considerations Related to Phosphating . 49

6.5.1 Choosing a Phosphate Formulation and Qualifying the Phosphate Coating. 49

6.5.2 Degreasing Before Phosphating . 49

6.5.3 Design of an Immersion Tank System 50

6.5.4 Design of a Spray Washer System. 50

6.5.5 Process and Quality Control Measures51

6.6 References 51

6.7 Additional Reading 52

Chapter 7 Rinsing Process Efficiency and Alternatives to Chromate-Based Sealers . 53

7.1 introduction 53

7.1 .l Pollution Prevention Considerations 53

7.1.2 Decision-Making Criteria . 53

7.2 Rinsing . 53

7.2.1 Rinsing Basics and Best Management Practices55

7.2.2 Counter-Flow Rinsing. . 57

7.3 Sealing . 59

7.3.1 Sealing Basics . 59

7.3.2 Chromate-Based Sealing Rinses Versus Nontoxic Afternatives. 60

7.4 Case Example 61

7.5 References 62

7.6 ‘Additional Reading 62

Chapter 6 (0 Abrasive Blast Cleaning of Metal Surfaces: Process Efficiency 63

8.1 .l Pollution Prevention Considerations -63

8.1.2 Decision-Making Criteria . 63

Process Basics . 63

8.2.1 Introduction 63

6.2.2 Abrasive Blasting Systems . 64

8.2.3 Media Recycling65

8.2.4 Blast Profile as a Critical Factor . 66

8.2.5 Types of Abrasive Media and Selection Criteria . 67

8.2.6 Blast Cleaning Standards 68

Best Management Practices. 69

Process Variations (With Case Examples)70

8.4.1 Abrasive Blasting Preceded by Degreasing 70

8.4.2 Abrasive Blasting Followed by Phosphating 71

References . 71

SECTION 3 Application Process Factors . 73

Chapter 9 Transfer Efficiency as It Affects Air, Water, and Hazardous Waste Pollution . 74

9.1 Introduction 74

9.1.1 Pollution Prevention Considerations 74

9.1.2 Decision-Making Criteria . 74

9.2 Benefits of improved Transfer Efficiency . 74

9.2.1 Reductions in Pollution and Related Factors . 75

9.2.2 Reduction in Costs 76

9.3 Methods for Measuring Transfer Efficiency . 77

9.3.1 Defining Parameters Before Commencing the Transfer Efficiency Test. 77

9.3.2 Using the Weight (Mass) Method 78

9.3.3 Using the Volume Method 79

9.4 The Effects of Common Spray Guns on Transfer Efficiency79

9.4.1 Conventional Air Atomizing Spray Guns . 79