From Handbook of Adhesives and Sealants, Volume 2

6.1 Introduction

6.1.1 Historical Background

In the distant past (pre-1970), bonding of structures, especially in the aircraft industry, was characterised by the use of adhesives with very high strength applied in thin layers. This type of adhesive was usually referred to as structural and was either based on phenolic resins (in the 1940s) or, beginning in the 1950s, on epoxy resins. They have been used for many years, but with increasing use their main disadvantage has become obvious. Such adhesives are generally very brittle and exhibit poor impact behaviour. Therefore, many attempts have been made to improve the impact resistance of epoxy adhesives. In discussion with engineers and experts familiar with adhesive bonding, the general opinion was that bonding can only be successful if the lap shear strength is higher than 10 MPa.

The structural glazing of facades was introduced in the 1960s. A silicone sealant was used to bond the isolating glass together and this fulfilled the important requirements of UV-resistance, thermal stability, durable elasticity, and adhesion to glass and frame materials (Fig. 2).

Figure 2: Example of structural glazing of facades, Berlin. This requires a flexible bond and seal.

In 1964, another key development started when the US automotive industry had to fulfill safety standards which required the retention of the windshield in a crash and thus, to ensure that the occupants remained inside the car (FMVSS 212). The windshield bonding technology involved has been called direct glazing ever since. At that time, direct glazing was achieved by...

Products & Services
Thermosets and Thermoset Resins
Thermosets and thermoset materials are crosslinked polymeric resins that are cured or set using heat or heat and pressure. They generally have a higher resistance to heat than thermoplastics.
Epoxy Adhesives
Epoxy adhesives are chemical compounds for joining components. They require clean surfaces and are valued for their toughness and resistance to chemical and environmental damage.
Adhesive Tapes
Adhesive tapes are used to assemble materials or parts together using a sticky chemical bond. Adhesive tapes are made by coating a backing or carrier (paper, plastic film, cloth, foam or foil) with an adhesive on a web or roll coater.
Insulating Varnishes and Impregnating Resins
Insulating varnishes and impregnating resins are designed for applications that require a low-viscosity resin or varnish for coil impregnation or magnet wire coating insulation. The resin may infiltrate the coil or electrical device through dipping, trick

Topics of Interest

6.2 Principal Advantages and Limits of Elastic Bonding The purpose of this chapter is to explain the principles and mechanisms of Elastic Bonding Technology in simple language and to serve as a...

6.8 Elastic Bonding in Practice In this section, different applications of Elastic Bonding Technology are described. 6.8.1 Crash-Resistant Direct Glazing Adhesives One-component polyurethane...

16.10 Glass and Ceramics Glass and ceramic substrates are generally high surface energy materials, and most adhesives wet them readily. One problem in bonding optically clear glass is to select an...

5.3 Alloyed or Modified (Two-Polymer) Adhesives These adhesives are important as structural adhesives especially in metal bonding. They comprise a thermosetting and a thermoplastic polymer, including...

Overview This chapter discusses individual adhesive types in detail. As a matter of convenience, the adhesives have been arranged in alphabetical order without regard to classification. See Chapter 4...