Archived Viewpoints

About Structural Adhesives

May 2004

In general, structural adhesives are high-performance adhesives capable of producing rigid, high-strength, almost permanent bonds between substrates in continuously stressed assemblies under relatively severe service conditions for relatively long periods of time. Structural adhesives based on epoxy, urethane, acrylic, and other high-temperature polymers have use in joining materials in aircraft/aerospace, automotive, electrical/electronics, building/construction, and consumer/appliance applications. Structural adhesives have good adhesion to a variety of substrates, allow very quick application, have excellent properties, and can be cost-effective.

Structural adhesives provide numerous manufacturing advantages to designers. First, the materials permit the joining of diverse materials. Plastics and composites do not lend themselves to welds or mechanical fasteners because of problems with stress concentration, cracking, and fatigue. And such lightweight materials as aluminum or magnesium may distort during welding. Engineers who wish to design with advanced materials, therefore, must rely on adhesives. Second, welding equipment cannot access tight bends; thus, structural adhesives facilitate smoother, sleeker designs than welds or mechanical fasteners do. Last, adhesives work better with automated manufacturing processes and allow greater parts consolidation than traditional alternatives allow.

Profitability of structural adhesives producers is above average for all specialty-chemical business area and is likely only to improve further for those companies that are technology leaders and innovative marketers, particularly in aerospace/aircraft, ground-transportation, and electrical/electronics applications. Producers must offer competitive products, quality, and technical service. In addition, producers must cope with increasing environmental legislation—especially recycling laws. Adhesive bonding of structural components in high-volume manufacturing operations is becoming practical and offers much opportunity. The importance of adhesives continues to grow with the many new advances in adhesives technology and the use of adhesives is growing across all industries.