Adhesive Bonding: Science, Technology and Applications

Front Cover
Adhesive Bonding: Science, Technology and Applications
Copyright
Contents
Contributors
Part One: Fundamentals of adhesive bonding
Chapter 1: A history of adhesive bonding
1.1. Introduction
1.2. Adhesives in nature
1.3. Prehistoric adhesives
1.3.1. Adhesives from Birch Bark Pitch
1.3.2. Bitumen adhesives
1.3.3. Animal glues
1.3.4. The development of more complex adhesives
1.4. Classical civilisations: Egyptians, Greeks, and Romans
1.4.1. Egyptian use of bonding
1.4.2. Biblical references
1.4.3. Adhesives in ancient Greece and Rome
1.5. Mediaeval artists
1.6. Mediaeval literature
1.7. Renaissance science and philosophy
1.8. The industrialisation of glue making
1.8.1. The earliest glue works
1.8.2. The growth of glue making
1.8.3. The industrial production of animal glue
1.8.4. Glue testing and science
1.9. The advent of synthetic polymers
1.10. The present status
References
Chapter 2: What are adhesives and sealants and how do they work?
2.1. Introduction
2.2. Bulk properties
2.2.1. Glass transition temperature (Tg)
2.2.2. Measurement of Tg
2.2.3. Free volume theory
2.2.4. Crosslinking
2.2.5. Detection and measurement of crosslinks
2.2.6. Crystallinity
2.3. Adhesives which harden by loss of solvent
2.4. Adhesives which harden by loss of water
2.4.1. Water solutions and pastes
2.4.2. Latex adhesives
2.5. Adhesives which harden by cooling
2.5.1. Ethylene-vinyl acetate (EVA) hot melts
2.5.2. Polyamide hot melts
2.6. Adhesives which harden by chemical reaction
2.6.1. Epoxides
2.6.2. Phenolic adhesives for metals
2.6.3. Structural acrylic adhesives
2.6.4. Rubber toughening of structural adhesives
2.6.5. High-temperature adhesives
2.6.6. Formaldehyde condensate adhesives for wood
2.6.7. Anaerobic adhesives
2.6.8. Cyanoacrylates
2.6.9. Silicones
2.6.10. Polyurethanes
2.6.11. Polysulphides
2.7. Pressure-sensitive adhesives
2.7.1. Tape materials
2.7.2. Latices
2.7.3. Block copolymers
2.7.4. Acrylics
2.7.5. Atactic polypropylene
2.7.6. Tackifiers
2.8. Adhesion by physical adsorption
2.8.1. Introduction
2.8.2. Contact mechanics
2.8.3. Contact angles
2.8.4. Thermodynamic work of adhesion
2.9. Adhesion by chemical bonding
2.9.1. Covalent bonds
2.9.2. Ionic bonds
2.9.3. The unique properties of water
2.9.4. Hydrogen bonds
2.9.5. Lewis acid-base interactions
2.10. The electrostatic theory of adhesion
2.11. Mechanical interlocking
2.12. Adhesion by interdiffusion
2.13. Weak boundary layers
2.14. Pressure-sensitive adhesion
References
Chapter 3: Surfaces: How to assess
3.1. Introduction
3.2. Surface topography
3.2.1. Scanning electron microscopy (SEM)a
3.2.2. Confocal laser scanning microscopy (CLSM)
3.2.3. Stylus profilometry
3.2.4. Scanning probe microscopy (SPM)
3.3. Surface thermodynamics
3.3.1. Wetting and spreading of liquids on solid surfaces
3.3.2. The water break test
3.3.3. Dyne test markers
3.3.4. Determination of surface free energy
3.4. Surface chemical analysis
3.4.1. X-ray photoelectron spectroscopy and auger electron spectroscopy
3.4.2. Time-of-flight secondary ion mass spectrometry (ToF-SIMS)
3.5. Compositional depth profiling by XPS and ToF-SIMS
3.6. Forensic analysis of failed joints
3.7. Concluding remarks
Acknowledgements
References
Chapter 4: Surface pretreatments for optimised adhesive bonding
4.1. Introduction
4.2. Cleaning surfaces
4.3. General pretreatments for metals
4.3.1. Surface pretreatments for carbon steels
4.3.2. Surface pretreatments for aluminium alloys
4.4. Pretreatments for polymers
4.5. Pretreatments for glass
4.6. Summary
References
Chapter 5: Properties of adhesives
5.1. Introduction
5.2. Chemical/physical characterisation and properties
5.2.1. Polymer molecular weight
5.2.2. Cure chemistry properties
5.2.3. Glass transition and crystalline melting
5.2.4. Residual stress
5.2.5. Viscoelasticity
5.2.6. Cross-link density
5.2.7. Thermal conductivity
5.3. Electrical properties
5.4. Process parameters
5.4.1. Rheology
5.4.2. Pot-life or working life
5.4.3. Cure cycle
5.4.4. Slump
5.5. Mechanical properties
5.5.1. Constitutive properties
5.5.2. Testing
5.6. Mechanical capability
5.7. Conclusions
References
Part Two: Mechanical properties
Chapter 6: Stress analysis of adhesive joints
6.1. Introduction
6.2. Different stress types and sources
6.2.1. Stress and strain concepts
6.2.2. Plane stress vs. plane strain
6.2.3. Different stress types in adhesive joints
6.2.4. Sources of adhesive joint stresses
6.2.4.1. Mechanical loading
6.2.4.2. Thermal stresses
6.2.4.3. Swelling stresses
6.3. Analytical approaches
6.3.1. Lap shear joints (single lap and double lap configurations)
6.3.2. Other joint configurations
6.3.2.1. Peel joints
6.3.2.2. Scarf and stepped joints
6.3.2.3. Butt joints
6.3.3. Software package
6.4. Numerical methods
6.4.1. Complex configurations
6.4.2. Complex material responses
6.4.2.1. Elasto-plasticity
6.4.2.2. Hyper-elasticity
6.4.2.3. Time and strain rate dependent behaviour
6.4.3. Advanced numerical approaches
6.5. Conclusion
References
Chapter 7: Environmental (durability) effects
7.1. Introduction
7.2. Additives to reduce photo-oxidative degradation
7.3. Behaviour of structural joints to metals in wet surroundings
7.3.1. Effect of humidity
7.3.2. Surface treatment
7.3.3. Natural and accelerated ageing
7.3.4. Salt water
7.3.5. Stress
7.3.6. Alloy type
7.4. Water and adhesives
7.4.1. Water diffusion into adhesive bondlines
7.4.2. Reversible and irreversible processes
7.4.3. Hydrolysis
7.5. Water and adhesive interfaces
7.5.1. Oxide stability
7.5.2. Physical adsorption and work of adhesion
7.5.3. Chemical bonds
7.6. Other fluids
7.7. Timber joints
References
Chapter 8: Nondestructive inspection of adhesive bonded joints
8.1. Introduction
8.2. Conventional ultrasonic methods
8.2.1. Basis of the technique
8.2.2. Test configurations
8.2.2.1. Through-transmission
8.2.3. Pulse-echo
8.2.4. Ultrasonic transducers and data presentation
8.2.4.1. Effect of frequency
8.3. Bond testers
8.3.1. Ultrasonic bond testers
8.3.2. Sonic bond testers
8.3.3. Bond testers and bond strength
8.4. Quality control and visual inspection
8.5. Contamination of surfaces
8.5.1. Surface energy and bond strength
8.5.2. Classification of contaminates
8.5.3. Airborne contamination
8.5.4. Contact contamination
8.6. Rapid scanning methods
8.6.1. Transient thermography
8.6.2. Shearography
8.7. Monitoring environmental degradation
8.8. Conclusions
References
Chapter 9: High-rate loading and impact in adhesively bonding joints
9.1. Introduction
9.2. Definition of high rate loading and impact
9.2.1. Stress wave
9.2.2. Loading rate dependency of material properties
9.3. Deformation of adhesively bonded joints subjected to high-rate loading or impact
9.3.1. Theoretical approach
9.3.2. Dynamic finite element analysis
9.3.3. Strength criteria of adhesively bonded joints
9.3.3.1. Maxim stress criterion
9.3.3.2. Maximum strain criterion
9.3.3.3. Criterion based on fracture and damage mechanics
9.4. Experimental methods and standards
9.4.1. Test standards for impact tests
9.4.1.1. Block impact test
9.4.1.2. Impact wedge peel test
9.4.2. Measurement
9.4.2.1. Load measurement
9.4.2.2. Measurement of deformation and strain
9.4.3. Testing methods
9.4.3.1. Hydraulic high-speed testing machine
9.4.3.2. Drop weight testing machine
9.4.3.3. Split Hopkinson bar equipment
9.4.3.4. Influence of loading modes
9.4.3.5. Fracture mechanics
9.5. Design of adhesively bonded joints subjected to impact loading
9.6. Conclusion
References
Chapter 10: Applying fracture mechanics to adhesive bonds
10.1. Introduction
10.2. An energy criterion for failure
10.3. The stress intensity factor approach
10.3.1. Cracks in monolithic materials
10.3.2. Cracks at interfaces
10.4. The energy release rate approach
10.5. Thermodynamic, intrinsic, and practical adhesion energy
10.6. Experimental evaluation of fracture energy
10.7. The effect of bondline thickness
10.8. The effect of mode Mixity
10.9. Durability
10.10. Designing with fracture mechanics
10.11. Recent developments and current research areas
10.12. Conclusions
References
Chapter 11: Fatigue
11.1. Introduction
11.2. General aspects of fatigue
11.2.1. Fatigue loads
11.2.2. Analysis and prediction of fatigue
11.2.3. Experimental testing
11.2.4. Environmental effects
11.3. Total life methods
11.3.1. The stress life approach
11.3.1.1. Fatigue-loading effects
11.3.1.2. Effect of test geometry and lifetime prediction
11.3.1.3. Fatigue limit
11.3.1.4. Cumulative damage methods
11.3.2. Strain life approach
11.4. Fracture mechanics approach
11.4.1. Introduction
11.4.2. Fatigue-loading effects
11.4.3. Fatigue life prediction using FCG analysis
11.4.4. Variable amplitude fatigue
11.4.5. Fatigue initiation
11.5. Strength and stiffness wear-out approaches
11.5.1. Strength degradation under constant amplitude loading
11.5.2. Strength degradation under variable amplitude loading
11.5.3. Stiffness degradation
11.6. Damage mechanics approach
11.6.1. Cohesive zone modelling
11.6.2. Continuum damage mechanics
11.7. Creep-fatigue
11.8. Impact fatigue
11.9. Fatigue strength improvement
11.10. Summary and future directions
References
Chapter 12: Vibration damping
12.1. Introduction
12.2. Damping in structures
12.3. Damping due to friction in joints
12.4. Damping due to structural adhesive bonding
12.5. Constrained and unconstrained damping treatments
12.6. Experimental data on vibration damping of adhesively bonded joints
12.6.1. Lap joint modal test
12.6.2. Lap joint tensile test
12.6.3. Adhesive tensile strength
12.6.4. Adhesive DMTA
12.7. Future trends
References
Chapter 13: Joining similar and dissimilar materials
13.1. Introduction
13.2. Joint design
13.2.1. Overview
13.2.2. Material effects-Coefficient of thermal expansion
13.2.3. Factors affecting adhesive properties
13.2.3.1. Physical structure
13.2.3.2. Glass transition temperature (Tg)
13.2.3.3. Cure type
13.2.3.4. Solvent uptake
13.2.3.5. Unreacted materials
13.2.4. Corrosion
13.2.5. Anisotropy
13.3. Adhesive selection
13.3.1. Overview
13.3.2. Chemical effects
13.3.3. Physical effects
13.3.4. Design needs
13.4. Surface pretreatments
13.4.1. Overview
13.4.2. Metals
13.4.3. Polymers
13.5. Assembly issues and hybrid joining
13.5.1. Introduction
13.5.2. Internal agents
13.5.2.1. Fillers
13.5.2.2. Glass beads
13.5.2.3. Wires or shims
13.5.2.4. Carrier materials and tapes
13.5.2.5. Joint detail (threads, ridges, pips, troughs, etc.)
13.5.3. External agents
13.5.3.1. Clamps and shims
13.5.3.2. Tooling
13.5.3.3. Presses and plates
13.5.3.4. Fasteners (nails, bolts, rivets)
13.5.4. Combination or hybrid joining
13.5.5. Conclusions
13.6. Future trends
Bibliography
Chapter 14: Effect of disassembly on environmental and recycling issues in bonded joints
14.1. Introduction
14.2. Impact of adhesive bonding in the environment
14.2.1. Categories of environmental issues
14.2.2. Greenhouse gas emission
14.2.3. Use of finite resources
14.3. Basic strategies to meet the challenge for environmental issues
14.3.1. Use of environmentally friendly materials
14.3.2. Addition of rework or disassembly properties to the adhesive
14.3.3. Recycling of adhesives
14.3.4. Optimisation of the bonding process
14.3.5. Design optimisation and life cycle assessment of adhesively bonded joints
14.4. Types, characteristics, and applications of dismantlable adhesives
14.4.1. Thermoplastic adhesives, i.e. hot melt adhesives (molten adhesives)
14.4.2. Adhesives including blowing agents or expansion agents
14.4.3. Adhesives including chemically active materials
14.4.4. Electrochemically dismantlable adhesive
14.4.5. Miscellaneous methods
14.5. Recent progress
14.5.1. New application
14.5.2. Modification of matrix resin
14.5.3. Compromise of strength and dismantlability
14.6. Future seeds
14.6.1. Use of chemical decomposition and degradation
14.6.2. Novel heating methods
14.6.3. Other stimulation methods
14.7. Conclusion
References
Chapter 15: Adhesively bonded repairs to highly loaded structure
15.1. Introduction
15.1.1. Classification of aircraft structures
15.1.2. Structural repair general requirements
15.1.3. FAA certification requirements for adhesively bonded structures
15.2. Repair of metallic components
15.2.1. Damage and repair options
15.2.2. Patch materials options
15.2.3. Patch design
15.2.4. Estimation of stress intensity reduction in patched cracks
15.2.5. Experimental correlation with Roses model
15.2.6. Transfer length
15.2.7. Damage tolerance and patch zoning
15.2.8. Acquisition of materials of allowables for design of the patch system
15.2.9. Estimation of design limit stress for repair design
15.3. Repair of composite components
15.3.1. Damage types and assessment
15.3.2. Patch options for highly loaded structure
15.3.3. Simple design approaches
15.3.4. External patch repairs
15.3.5. Bond strength analysis
15.3.6. Damage tolerance of external patch repairs
15.3.7. Simple design of scarf repairs
15.3.8. Studies on scarf joints representing repairs
15.3.9. Design of stepped repairs
15.3.10. Reducing the cut-out size
15.3.11. Damage tolerance of flush repairs
15.4. Materials engineering
15.4.1. Surface preparation for repair
15.4.2. Surface treatment
15.4.2.1. Metals
15.4.2.2. Composites
15.4.3. Patch materials and adhesives
15.4.4. Options for patch formation
15.4.5. Repair adhesive bonding
15.4.6. Moisture problems in composites repair
15.4.7. Protection of repairs against lightning strike
15.5. Assessment of structural integrity in bonded repairs
15.5.1. Inspection issues and approaches
15.5.2. The proof test approach
15.5.3. Structural health monitoring
15.5.4. Some applications to primary metallic airframe structure
15.5.4.1. USAF C141
15.5.4.2. F16 lower-wing skin repair
15.5.4.3. RAAF F-111 lower-wing skin repair
15.6. Reinforcement
15.6.1. Scope
15.6.2. Selected applications
15.6.2.1. HMAS sydney FFG-7
15.6.2.2. F111 wing-pivot fitting
15.6.2.3. FA/18 wing attachment bulkheads
15.6.3. A proposed retrospective NDI approach: Fatigue life enhancement
15.7. Conclusions
Acknowledgements
References
Chapter 16: Adhesive bonding of composites
16.1. Introduction
16.2. The specific nature of composite materials
16.3. Design of bonded composite assemblies
16.4. Surface preparation
16.5. Testing
16.6. Influence of bondline thickness
16.7. Examples of bonded composite structures
16.8. Durability and long-term performance
16.9. Future trends
16.10. Sources of information
Acknowledgements
References
Further reading
Chapter 17: Building and construction steel and aluminium
17.1. Introduction
17.2. Generalities to adhesive selection
17.3. Strength of bonded joints
17.3.1. Dimensioning adhesively bonded tubular joints
17.3.2. Dimensioning steel hybrid joints
17.4. Surface preparation
17.4.1. Theory
17.4.2. Practical example
17.5. Additional aspects
17.5.1. Environmental conditions and ageing
17.5.2. Fatigue
17.5.3. Adhesively bonded reinforcements of steel structures
17.5.4. Questions related to adhesive suitable construction concepts in structural scale
17.5.5. Questions related to quality control
References
Chapter 18: Building and construction: Timber engineering and wood-based products
18.1. Introduction and overview
18.2. Basic needs and applications
18.3. Wood characteristics
18.4. Wood-adhesive bond formation and performance
18.4.1. Wood material and surface preparation
18.4.2. Adhesive properties
18.4.3. Gluing process
18.4.4. Mechanical, climatic, environmental factors and behaviour in fire
18.4.5. Testing methods
18.5. Strength and durability
18.5.1. Influence of wood and adhesive properties
18.5.2. Duration of load (DOL) effects and influence of climate
18.5.3. Predicting wood-adhesive joint failure
18.6. Common failures, testing, and quality control
18.7. Repair
18.8. Examples of use
18.9. Future trends and further reading
18.9.1. Environment
18.9.2. Broadened fields of application
18.9.3. Improved prediction and control of product performance and adhesive formulation
18.9.4. Improved material handling
18.9.5. Further reading
References
Chapter 19: Automobiles
19.1. Introduction
19.2. Basic needs
19.2.1. Materials used in modern cars
19.2.2. Process chain in automobile construction
19.2.3. Body shop
19.2.4. Paint shop, trim assembly
19.2.5. Power train assembly
19.2.6. Adhesives in the body shop
19.2.7. Bonding in the trim assembly
19.2.8. Adhesives in the power train
19.2.9. Loads
19.2.9.1. Loads during production
19.2.9.2. Loads during use
19.3. Adhesive characteristics required
19.3.1. Required characteristics during production
19.3.2. Required adhesive characteristics during use of the vehicle
19.3.2.1. Corrosion protection
19.3.2.2. Stiffness
19.3.2.3. Crash
19.4. Surface preparation
19.4.1. Steel
19.4.2. Aluminium
19.4.3. Magnesium
19.4.4. Plastics
19.4.5. Duromers
19.4.6. Thermoplastics
19.4.7. Precoated/painted panels
19.5. Strength and durability
19.5.1. Strength
19.5.2. Structural adhesive bondings
19.5.3. Semistructural adhesive bondings
19.5.3.1. Anti-flutter adhesives
19.5.4. Screen bonding/direct glazing
19.5.5. Durability
19.6. Common failures
19.7. Inspection, testing, and quality control
19.8. Repair and recycling
19.9. Other industry-specific factors
19.10. Examples for use
19.10.1. Adhesive bonding in body in white
19.10.2. Adhesives in E-mobility
19.10.3. Adhesives in buses and trucks
References
Chapter 20: Boats and marine
20.1. Basic needs
20.1.1. Typical materials of adherends
20.1.2. Types of connections
20.1.2.1. Adhesive bonding vs laminating in FRP hulls
20.1.2.2. Adhesive bonding vs bolting in FRP substructure-Metal hull connections
20.1.3. Load characteristics
20.1.3.1. Global loads
20.1.3.2. Local loads
20.1.4. Other requirements
20.2. Adhesive characteristics required
20.2.1. Moisture resistance
20.2.2. Heat resistance
20.2.3. UV resistance
20.2.4. Joint thickness
20.2.5. Strength and stiffness
20.2.6. Curing time and viscosity
20.3. Surface preparation
20.3.1. An example of surface treatment on joints between FRP and metal
20.3.1.1. Joints between aluminium and FRP
20.3.1.2. Joints between AISI 316 and FRP
20.4. Strength and durability
20.4.1. Designing for strength
20.4.1.1. Joint edge shape
20.4.1.2. Analytical methods for calculating the strength of adhesive-bonded joints
20.4.1.3. Finite element techniques and solution methods
20.4.2. Testing
20.5. Common failures
20.6. Inspection, testing, and quality control
20.6.1. Inspection methods
20.7. Repair
20.8. Examples of use
20.8.1. Hull-deck joint in small FRP boats
20.8.2. Replacing bolts with adhesive bonding in a joint between aluminium hull and FRP sandwich deckhouse [2]
20.8.2.1. Comparison of the joint with a similar bolted joint type
20.9. Future trends
References
Chapter 21: Bonding in the shoe industry
21.1. Introduction
21.2. Overview of the shoe bonding protocol
21.3. Surface preparation of the upper materials
21.3.1. Surface preparation of leather upper
21.3.2. Surface preparation of nonleather upper
21.4. Surface preparation of soles
21.4.1. Surface preparation of natural-based material soles
21.4.2. Surface preparation of rubber soles
21.4.2.1. Surface preparation of nonvulcanised rubber soles
21.4.2.2. Surface preparation of vulcanised rubber soles
21.4.3. Surface preparation of polymeric material soles
21.5. Adhesives used in shoe bonding
21.5.1. Polyurethane adhesives in shoe bonding
21.5.1.1. Solvent-borne polyurethane adhesives
21.5.1.2. Waterborne polyurethane adhesives
21.5.1.3. Solvent-free polyurethane adhesives
21.5.2. Polychloroprene (neoprene) adhesives in shoe bonding
21.5.2.1. Solvent-borne polychloroprene adhesives
21.5.2.2. Waterborne polychloroprene adhesives
21.6. Testing, quality control, and durability
21.6.1. Selection of the upper and sole materials
21.6.2. Selection of the adhesive
21.6.3. Design of the joint
21.6.4. Adequate bonding operation
21.6.4.1. Adequate and efficient surface preparation of upper and sole surfaces
21.6.4.2. Adhesive application
21.6.4.3. Adhesive film drying
21.6.4.4. Bond formation
21.6.4.5. Crystallisation or curing of the adhesive
21.6.5. Types of tests
21.7. Future trends
Acknowledgements
References
Chapter 22: Electrical and electronics
22.1. Introduction
22.2. Basic needs
22.3. Adhesive characteristics
22.3.1. Polymer for encapsulation: Material Processes and Reliability
22.3.2. Conductive adhesives
22.3.2.1. Fillers
22.3.2.2. Isotropic conductive adhesives (ICAs)
22.3.2.3. Anisotropic conductive adhesives (ACAs)
22.3.2.4. Nonconductive adhesives (NCAs)
22.3.2.5. Inherent conductive polymers
22.4. Surface preparation
22.5. Strength and durability: Reliability
22.6. Common failures
22.7. Inspection, testing, and quality control
22.8. Examples of use
22.8.1. Printed circuit board
22.8.2. Surface-mount devices
22.8.3. Die attach
22.8.4. Flip-chip
22.8.5. Underfill
22.8.6. Smartcards
22.8.7. Display applications
22.8.8. Microsystems
22.8.9. Power electronics
22.8.10. Flexible/stretchable electronics
22.9. Conclusion
References
Chapter 23: Aerospace industry applications of adhesive bonding
23.1. Introduction
23.2. Adhesive characteristics required for design and analysis
23.3. Surface preparation
23.4. Design of adhesively bonded jointsc
23.5. Design features ensuring durability of bonded joints
23.6. Load redistribution around flaws and porosity
23.7. Effects of thermal mismatch between adherends on strength of bonded joints
23.8. Inspection, testing, and quality control
23.9. Bonded repairs and estimates of residual strength after apparent disbonds
23.10. Other industry-specific factors
23.11. Examples of use of adhesive bonding in aircraft structures
23.12. Rules of thumb
References
Index
Back Cover