Epoxy Adhesive Formulations
Based on a popular course sponsored by the Society of Plastics Engineers, this comprehensive text presents a variety of methods to ensure optimum epoxy performance and reliability.
TABLE OF CONTENTS Epoxy Adhesive Formulations
Chapter 12: Elevated-Temperature Curing Liquid and Paste Epoxy Adhesives
12.1 INTRODUCTION
Although room temperature curing epoxy adhesives are very convenient to use in many applications, the short working life, long curing time, and inherently suboptimal physical properties of these systems are often a serious disadvantage to their use. In these cases, elevated-temperature curing epoxy adhesives are required. The major advantages and disadvantages of elevated-temperature curing epoxy adhesives are shown in Table 12.1.
| Advantages | Disadvantages |
|---|---|
| Fast cure time results in higher production speed and less tie-up of fixturing equipment | Greater internal stresses than in room temperature curing adhesive because of
|
| Long working life | More brittle than room temperature curing adhesives (poorer peel and impact properties) |
| High-temperature resistance | Safety and hazardous nature of high temperatures |
| Good chemical resistance | One-component systems have shorter shelf life; may require refrigeration |
| One-component systems possible (no need to meter and mix) | Solid systems easier to apply, less of a health hazard than liquids or pastes |
| Long shelf life for two-component systems | Energy consumption |
| Solid systems (film, preforms, powders) possible | Viscosity of adhesive decrease at elevated temperature could result in starved joint |
| Viscosity decrease at elevated temperature provides more efficient wetting of substrate |
Heat curing epoxy systems may consist of one or two components. The nomenclature is similar to that employed with the room temperature curing adhesives (e.g., resin component, curing agent component, 2K system, etc.). Many heat curing epoxy adhesives systems are liquids or pastes. However,...
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