Adhesives

Robert P. Jackson, P.E.

Course Outline

This course is written specifically for the purpose of providing a basic understanding of adhesive systems.  It is a very broad subject so we are limiting the descriptive information to adhesives only and omitting sealants, thread locking adhesives, potting compounds, encapsulating compounds, gasketing materials, etc.    These subjects are very interesting but complex to the point of deserving a more detailed look on an individual basis.  We will concentrate solely on adhesives products used for bonding two or more substrates together.   When we say systems, we are referring to 1.) Adhesives types and selection, 2.) Cleaning and pretreatment of substrates and 3.) Joint design.  All three areas are integral to successful bonding, and accomplished properly, can provide for prolonged operational life.   We also cover adhesive history, global markets, adhesive uses, standards and testing methods and equipment.     By the end of the course, we want to impart a fundamental understanding of an industry that has significant annual growth and represents an important technology.  We hope to pique your interest to the point of wanting to know more and providing a solid foundation upon which to build. 

This course includes a multiple choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

The learning objectives of this course are as follows:

• To instill an awareness of how prevalent adhesive usage is in our everyday lives and to give an idea as to global usage.  We will provide a quick look at some of the products benefitting from adhesives also;
• Knowledge of the advantages and disadvantages when using adhesives;
• A basic knowledge regarding the theories of adhesion and adhesive bonding;
• Knowledge about the principals of adhesive “wetting”.  What’s acceptable and what’s not acceptable;
• Knowledge of adhesive types and their basic structure;
• The difference between a one-part and a two-part adhesive;
• The basic selection criteria for adhesive types vs structural needs;
• An understanding of the tensile strength, peel strength, shear strength, gap fill, viscosity, etc relative to adhesive types;
• The major suppliers ( vendors ) in the global market;
• A guide that will give aid in choosing an acceptable adhesive relative to the substrates used.  This involves looking at the mechanical characteristics of each adhesive type;
• Knowledge of the three governing rules for joint design;
• A step by step checklist of questions that should be asked and answered prior to choosing an adhesive type;
• Guidelines for joint design;
• Information on surface preparation, cleaning and pretreatment;
• Knowledge relating to the various failure modes for adhesive joints;
• An awareness of what standards exist and govern adhesive usage;
• Test methods used to provide quality assurance and guidelines for selection;
• A discussion for PSTs ( Pressure Sensitive Tapes ), their construction and use;
• A complete glossary of terms for adhesives and tape products;
• A working knowledge of equipment used for dispensing one-part and two-part adhesives;
• A list of references for further study; and
• Knowledge relating to the history of adhesives.

Intended Audience

This five (5) hour course is intended for those individuals who require a basic knowledge of adhesives and adhesive systems.  Although it is primarily intended for engineers, engineering managers and architects, the text is written in a fashion that is easily understandable for anyone with a desire to gain knowledge over and above the “folklore” that seems to exist concerning “glues”.  The only “technical” part of the course is the discussion on the Theory of Adhesion.  We touch briefly on the chemistry of polymers and monomers and how they interact with substrates to form the bonds necessary for adhesion.  Failure mechanics of adhesive systems are quite complicated but I have chosen a more fundamental approach that lets the reader glean a quick understanding of how to choose the best adhesive for any one given job.   The text involving the adhesive selection is very informative and forms the focal point of the course.  The “dos” and “don’ts are enumerated relative to surface preparation and joint design so that a starting point may be had prior to choosing the proper adhesive system.   This course does not require the calculation of “wetting angles” or stresses relating to performance.  The sole purpose is informative.  There is a quiz at the end of the course which, is a learning tool also.

Benefit to Attendees

The purpose of this course is to provide an introductory body of information that will allow the engineer, engineering manager or corporate manager the basic resources to investigate the possibility of substituting an adhesive for an existing or envisioned mechanical fastening technique.   We wish to illustrate those key design practices; i.e. adhesive selection, joint design, cleanliness, pretreatment of substrates, etc. that ensure high levels of success with any application.   This course will also provide references for further study so that the understanding of basic concepts, as applied to commercial and consumer products, may be augmented for any one classification of adhesive or application.  Successfully completing this course will not make you an expert or a specialist but certainly will provide you with an understanding of the basics so further study will be possible and much less confusing.  Glossaries for adhesive materials and pressure-sensitive products are very complete and provide descriptive information that will definitely lessen time necessary to understand the given text.   We also have provided information, relative to viable manufacturers of material and equipment, so that searching for vendors becomes less time consuming and reduces the frustration factor

Course Introduction

The dictionary defines an adhesive as "a substance capable of holding materials together by surface attachment." This is a simple definition for materials that serve as the basis for a multi-billion dollar industry with more than 750 companies contributing to the manufacturing and sales effort. It is estimated that 50 of those companies are responsible for at least 50% of the sales dollars in the adhesive industry.

This course will examine adhesives and give an overview relative to adhesive types, uses, advantages and disadvantages, characteristics and various failure modes that could result due to use or over use.  Adhesive technology is a dynamic industry with new compounds being developed frequently to satisfy growing consumer and industrial needs.  “The need for speed” and bond strength, with minimal surface preparation, are the driving forces behind development efforts.  Oddly enough, retail cost seems to be a lesser concern when searching for a suitable material.  Get the job done right is the clarion call.  Our hope is that the material contained in this document will provide the foundation and desire for further study and the student will continue learning about this dynamic technology.

Course Content

The course content is in a PDF file:

Adhesives

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

Course Summary

This five (5) hour course is presented to those individuals who wish to know more about the subject of adhesives.  We will cover the following major topics in the text:

• History of Adhesives
• Global Usage—The tremendous increase in the use of adhesives, replacing mechanical fasteners, has been dramatic.  We discuss where the adhesive industry is today and what will be the increase over the next decade.
• Advantages and Disadvantages of adhesive use.
• Uses—This is a very brief look at where adhesives are used today.
• Theories of Adhesion—Very important section but we do not dwell on the chemistry of adhesive bonding.
• Adhesive Types
• Mechanical Characteristics of adhesives for each type.
• Joint Design
• Performance Considerations
• Epoxies, CAs and Pressure-Sensitive Tapes
• Failure Modes
• Standards
• Equipment
• Glossaries for Adhesives and Pressure-Sensitive Tapes

The course is definitely written with practicality in mind so that an individual may select the correct adhesive for given substrates in question; i.e. wood, metal, paper, plastic, etc.  Two of the most important sections in the text are joint design and substrate preparation.  “Gluing” two substrates together is more complicated than picking the adhesive from the corner drug store, especially if the application is industrial or commercial.  Cleanliness and pre-treatment are critical.  We explain how to accomplish a suitable interface so maximum success may be accomplished.  Since a picture is worth a thousand words, we have used many figures and tables to show and demonstrate concepts given in the text.  We have done this with the hope that the reader will come away with a very good “grounding” of and appreciation for the great variety of adhesives and processes available today.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.

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