Handbook of Adhesives and Surface Preparation: Technology, Applications and Manufacturing
450
Handbook of Adhesives and Surface Preparation: Technology, Applications and Manufacturing
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Overview
Handbook of Adhesives and Surface Preparation provides a thoroughly practical survey of all aspects of adhesives technology from selection and surface preparation to industrial applications and health and environmental factors. The resulting handbook is a hard-working reference for a wide range of engineers and technicians working in the adhesives industry and a variety of industry sectors that make considerable use of adhesives. Particular attention is given to adhesives applications in the automotive, aerospace, medical, dental and electronics sectors.
- A handbook that truly focuses on the applied aspects of adhesives selection and applications: this is a book that won't gather dust on the shelf
- Provides practical techniques for rendering materials surfaces adherable
- Sector-based studies explore the specific issues for automotive and aerospace, medical, dental and electronics
Product Details
| ISBN-13: | 9781437744620 |
|---|---|
| Publisher: | Elsevier Science |
| Publication date: | 12/15/2010 |
| Series: | Plastics Design Library |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 450 |
| File size: | 7 MB |
About the Author
He retired as a Senior Technology Associate in 2005 from the DuPont fluoropolymers after nearly 24 years of service. Sina founded of FluoroConsultants Group, LLC in 2006 where he continues to work. Sina earned his Bachelor of Science from the School of Engineering of the University of Tehran in 1976, Master of Science and PhD from the University of Michigan, Ann Arbor, all in Chemical Engineering.
He is author, editor and co-author of fifteen technical and data books including five handbooks on fluoropolymers technology and applications. He is author and co-author of three books in surface preparation and adhesion of materials, two of which are in their second editions. Sina has been involved with technical writing and publishing since 1974.
His experiences include fluoropolymer technologies (polytetrafluoroethylene and its copolymers) including polymerization, finishing, fabrication, product development, failure analysis, market development and technical service. Sina holds six patents.
Read an Excerpt
HANDBOOK OF ADHESIVES AND SURFACE PREPARATION
Technology, Applications and ManufacturingWilliam Andrew
Copyright © 2011 Elsevier Inc.All right reserved.
ISBN: 978-1-4377-4462-0
Chapter One
Introduction and Adhesion Theories Sina Ebnesajjad
1.1 Definition of Adhesives and Adhesive Bonding
An adhesive is a material that is applied to the surfaces of articles to join them permanently by an adhesive bonding process. An adhesive is a substance capable of forming bonds to each of the two parts when the final object consists of two sections that are bonded together. A feature of adhesives is the relatively small quantities that are required compared to the weight of the final objects.
Adhesion is difficult to define, and an entirely satisfactory definition has not been found. The following definition has been proposed by Wu. "Adhesion refers to the state in which two dissimilar bodies are held together by intimate interfacial contact such that mechanical force or work can be transferred across the interface. The interfacial forces holding the two phases together may arise from van der Waals forces, chemical bonding, or electrostatic attraction. Mechanical strength of the system is determined not only by the interfacial forces, but also by the mechanical properties of the interfacial zone and the two bulk phases."
There are two principal types of adhesive bonding: structural and nonstructural. Structural adhesive bonding is bonding for applications in which the adherends (the objects being bonded) may experience large stresses up to their yield point. Structural adhesive bonds must be capable of transmitting stress without losing of integrity within design limits. Bonds must also be durable throughout the useful service life of a part, which may be years. In addition to possessing significant resistance to aging, a structural bond is defined as having a shear strength greater than 7 MPa. Nonstructural adhesives are not required to support substantial loads but merely hold lightweight materials in place. This type of adhesive is sometimes called a "holding adhesive." Pressure-sensitive tapes and packaging adhesives are examples of nonstructural adhesives.
The distinction between structural and nonstructural bonds is not always clear. For example, is a hot melt adhesive used in retaining a fabric's plies structural or nonstructural? One may argue that such an adhesive can be placed in either classification. However, the superglues (cyanoacrylates) are classified as structural adhesives even though they have poor resistance to moisture and heat.
1.2 Functions of Adhesives
The primary function of adhesives is to join parts together. Adhesives accomplish this goal by transmitting stresses from one member to another in a manner that distributes the stresses much more uniformly than can be achieved with mechanical fasteners. Adhesive bonding often provides structures that are mechanically equivalent to or stronger than conventional assemblies at lower cost and weight. In mechanical fastening, the strength of the structure is limited to that of the areas of the members in contact with the fasteners. Obtaining adhesive bonds that are stronger than those of the strength of adherends is not unusual.
Smooth surfaces are an inherent advantage of adhesively joined structures and products. Exposed surfaces are not defaced and contours are not disturbed, as happens with mechanical fastening systems. This feature is important in function and appearance. Aerospace structures, including helicopter rotor blades, require smooth exteriors to minimize drag and to keep temperatures as low as possible. Lighter weight materials than are used with conventional fastening can often be used with adhesive bonding because the uniform stress distribution in the joint permits full utilization of the strength and rigidity of the adherends. Adhesive bonding provides much larger areas for stress transfer throughout the part, thereby decreasing stress concentration in small areas.
Dissimilar materials, including plastics, are readily joined by many adhesives, provided that proper surface treatments are used. Adhesives can be used to join metals, plastics, ceramics, cork, rubber, and combinations of materials. Adhesives can also be formulated to be conductive. The focus of this book is on adhesives for bonding plastics, thermosets, elastomers, and metals.
Where temperature variations are encountered in the service of an item containing dissimilar materials, adhesives perform another useful function. Flexible adhesives are able to accommodate differences in the thermal expansion coefficients of the adherends, and therefore prevent damage that might occur if stiff fastening systems were used.
Sealing is another important function of adhesive joining. The continuous bond seals out liquids or gases that do not attack the adhesive (or sealant). Adhesives/ sealants are often used in place of solid or cellular gaskets. Mechanical damping can be imparted to a structure through the use of adhesives formulated for that purpose. A related characteristic, fatigue resistance, can be improved by the ability of such adhesives to withstand cyclic strains and shock loads without cracking. In a properly designed joint, the adherends generally fail in fatigue before the adhesive fails. Thin or fragile parts can also be adhesively bonded. Adhesive joints do not usually impose heavy loads on the adherends, as in riveting, or localized heating, as in welding. The adherends are also relatively free from heat-induced distortion.
1.3 Classification of Adhesives
Adhesives as materials can be classified in a number of ways, such as chemical structure or functionality. Adhesives are categorized into two classes: natural and synthetic. The natural group includes animal glue, casein- and protein-based adhesives, and natural rubber adhesives. The synthetic group has been further divided into two subcategories industrial and special compounds. Industrial compounds include acrylics, epoxies, silicones, etc. An example of the specialty group is pressure-sensitive adhesives.
1.4 Advantages and Disadvantages of Joining Using Adhesives
The previous discussion highlighted a number of advantages of adhesive bonding. This section will cover both advantages and disadvantages of adhesive bonding, and some points are reiterated.
1.4.1 Advantages
• Uniform distribution of stress and larger stress-bearing area
• Joins thin or thick materials of any shape
• Joins similar or dissimilar materials
• Minimizes or prevent electrochemical (galvanic) corrosion between dissimilar materials
• Resists fatigue and cyclic loads
• Provides joints with smooth contours
• Seals joints against a variety of environments
• Insulates against heat transfer and electrical conductance (in some cases adhesives are designed to provide such conductance)
• The heat required to set the joint is usually too low to reduce the strength of the metal parts
• Dampens vibration and absorb shock
• Provides an attractive strength/weight ratio
• Quicker and/or cheaper to form than mechanical fastening
1.4.2 Disadvantages
• The bond does not permit visual examination of the bond area (unless the adherends are transparent)
• Careful surface preparation is required to obtain durable bonds, often with corrosive chemicals
• Long cure times may be needed, particularly where high cure temperatures are not used
• Holding fixtures, presses, ovens, and autoclaves, not usually required for other fastening methods, are necessities for adhesive bonding
• Upper service temperatures are limited to approximately 177°C in most cases, but special adhesives, usually more expensive, are available for limited use up to 371 °C
• Rigid process control, including emphasis on cleanliness, is required for most adhesives
• The useful life of the adhesive joint depends on the environment to which it is exposed
• Natural or vegetable-origin adhesives are subject to attack by bacteria, mold, rodents, or vermin
• Exposure to solvents used in cleaning or solvent cementing may present health problems
1.5 Requirements of a Good Bond
The basic requirements for a good adhesive bond are:
• Proper choice of adhesive
• Good joint design
• Cleanliness of surfaces
• Wetting of surfaces that are to be bonded together
• Proper adhesive bonding process (solidification and cure)
1.5.1 Proper Choice of Adhesive
There are numerous adhesives available for bonding materials. Selection of the adhesive type and form depends on the nature of adherends, performance requirements of the end use, and the adhesive bonding process.
1.5.2 Good Joint Design
Imparting strength to a joint by design is possible. A carefully designed joint yields a stronger bond than one not carefully designed when advantages of the mechanical design are combined with adhesive bond strength to meet the end use requirements of the bonded part.
1.5.3 Cleanliness
To obtain a good adhesive bond, starting with a clean adherend surface is essential. Foreign materials such as dirt, oil, moisture, and weak oxide layers must be removed, lest the adhesive be bonded to weak boundary layers rather than to the substrate. Various surface treatments exist that remove or strengthen the weak boundary layers. Such treatments typically involve physical or chemical processes, or a combination.
1.5.4 Wetting
Wetting is the displacement of air (or other gases) present on the surface of adherends by a liquid phase. The result of good wetting is greater contact area between the adherends and the adhesive over which the forces of adhesion may act.
1.5.5 Adhesive Bonding Process
Successful bonding of parts requires an appropriate process. The adhesive must not only be applied to the surfaces of the adherends; the bond should also be subjected to the proper temperature, pressure, and hold time. The liquid or film adhesive, once applied, must be capable of being converted into a solid in one of three ways. The method by which solidification occurs depends on the choice of adhesive. The ways in which liquid adhesives are converted to solids are:
• Chemical reaction by any combination of heat, pressure, and curing agents
• Cooling from a molten liquid
• Drying as a result of solvent evaporation
Requirements to form a good adhesive bond, as well as processes for bonding, analytic techniques, and quality control procedures, are discussed in this book.
1.6 Introduction to Theories of Adhesion
Historically, mechanical interlocking, electrostatic, diffusion, and adsorption/surface reaction theories have been postulated to describe mechanisms of adhesion. Theories have recently been postulated for adhesive bonding mechanisms (Table 1.1). It is often difficult to fully ascribe adhesive bonding to an individual mechanism is often difficult. A combination of different mechanisms is most probably responsible for bonding. The extent of the role of each mechanism may vary for different adhesive bonding systems. An understanding of these theories is helpful to those who work with adhesives.
(Continues...)
Excerpted from HANDBOOK OF ADHESIVES AND SURFACE PREPARATION Copyright © 2011 by Elsevier Inc. . Excerpted by permission of William Andrew. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Preface
PART I INTRODUCTION
Chapter 1 Introduction and Adhesion Theories (Chapter 1, from Adhesives Technology, 19
pages)
Chapter 2 Introduction to Surface Preparation (Chapter 1 from Surface Treatment, 5 pages)
PART II SURFACE PREPARATION
Chapter 3 Surface Tension and Its Measurement (Chapter 2 from Surface Treatment, 20
pages)
Chapter 4 Surface and Material Characterization Techniques (Chapter 4 from Surface
Treatment, 33
Chapter 5 Material Surface Preparation Techniques (Chapter 6 from Surface Treatment,
pages)
60
pages)
Chapter 6 Surface Preparation of Metals (Chapter 7 from Surface Treatment, 42 pages)
Chapter 7 Surface Preparation of Thermoplastics, Thermosets, and Elastomers (Chapter 8
from Surface Treatment, 54 pages)
PART III ADHESIVE CHARACTERISTICS
Chapter 8 Characteristics of Adhesive Materials (Chapter 5, from Adhesives Technology, 73
pages)
NEW: Chemical structures added
Chapter 9 Heat-resistant adhesives (Sections 4.1, 4.3, 4.4 and 4.5 from Chapter 4
Handbook of Adhesives and Sealants, Vol 2 by Philippe Cognard, 55
Chapter 10 UV-Radiation curing of adhesives (Section 5.1 to the end of Chapter 5 except
pages)
Handbook of Adhesives and Sealants, Vol 2 by Philippe Cognard, 37 pages)
PART IV ADHESIVES FOR APPLICATIONS
Chapter 11 Adhesives for Special Adherends (Chapter 6 from Adhesives Technology, 22
pages)
Chapter 12 Adhesives for Electronics (Sections 6.2, 6.3 and 6.4 from Chapter 6
of Handbook of Adhesives and Sealants, Vol 1 by Philippe Cognard, 45
Chapter 13 Adhesives for Automotive and Aerospace Applications (Sections 5.3, 5.4 and 5.5
from Chapter 5
pages)
of Handbook of Adhesives and Sealants, Vol 1 by Philippe Cognard, 32 pages)
Chapter 14 Adhesives for Medical and Dental Applications (New by Sina Ebnesajjad,
estimate 20
pages)
Appendix Safety, Environmental, Economic Aspects, and Future Trends (Chapter 13 from
Adhesives Technology, 20
NEW: Regulatory frameworks: REACH, ROHS, WEEE etc
pages)
Glossary (From Adhesives Technology, 25 pages)
Index
What People are Saying About This
A hard-working reference for anyone involved in choosing and using adhesives, the Applied Adhesives Handbook covers all aspects from surface preparation and adhesive selection to best practice tips and troubleshooting techniques for the industrial use of adhesives. Particular attention is given to adhesives applications in the automotive, aerospace, medical and electronics sectors