Structural adhesive automotive

Polyurethane pressure-sensitive adhesives began appearing in the early 1970s [15]. By 1978 advanced two-component automotive structural adhesives (Goodyear) were commercially available. Waterborne polyurethane adhesives received additional attention during this period [16]. In 1984, Bostik developed reactive hot-melt adhesives [17]. Polyurethane adhesives are sold into an ever-widening array of markets and products, where they are known for their excellent adhesion, flexibility, low-temperature... 

Table 1. Common Automotive Structural Adhesive Applications.

Several volumes will be published during 2005-2007 which contain chapters linked to the chapters in Volume 1, for instance Bonding metals , Bonding composites , Epoxy adhesives , Bonding in automotive , Structural adhesives , UV curing , Application equipment , and others. 

Although numerous studies (1-3) have described work aimed at establishing criteria for the durability of adhesive joints, a thorough understanding of effects of the chemical and mechanical properties, on the durability of adhesive bonds is lacking. More specifically, the effects of surface preparation and dynamic loading, especially under environmental service conditions, has not been explored in detail for automotive structures. In this paper, a description of the effects of environment on the durability of adhesive bonds is presented. Particular attention is given to... 

Epoxy adhesives have become the most recognizable structural adhesive type. They have found commercial success in demanding industries such as aerospace, automotive, building and construction, and electrical and electronic. Their ease of use has also encouraged their commercialization in the do-it-yourself markets, which has added to the exemplary reputation of epoxy adhesives. 

Just as their counterparts rejuvenated the aircraft industry decades ago, modem epoxy structural adhesives are providing automobile designers and manufacturers with innovative possibilities that could not have been considered only a short time ago. As a result, structural automotive adhesives will have an average annual growth rate of greater than 7 percent over the next 5 years.15 This growth rate is additive to any growth that will occur in the automotive industry itself. 

Some more recent examples of epoxy-urethane hybrids in one- and two-component structural adhesives are noted below. These have had success in the automotive industry where high impact strength, fatigue resistance, and high bond strength to a variety of substrates are valued characteristics. 

Fig. 13 Emissions fiom different PUR disk adhesives. Source Frank, U Development of emission-optimized automotive structural components with PUR, BMW AG (in German), Munich...

Highly cross-linked epoxy resins combine high strength stiffness thermal, chemical, and environmental stability adhesion low weight processability excellent creep resistance and favorable economics. These resins are widely applied as coatings, casting resins, structural adhesives, and matrix resins of advanced composite materials. The broad spectrum of applications ranges from the automotive and aerospace industries to corrosion protection and microelectronics. 

The nitrile-epoxy structural adhesive systems have moved from an aircraft orientation to include industrial, automotive and electronics areas. These include a host of film adhesive products (21, 22) and thixotropic pastes (23-26). Representative adhesive models have also been studied from a fracture toughness polnt-of-view permitting comparisons of bulk fracture to that of fracture in the adhesive joint (27, 28). 

The automotive industry is committed to plastic recovery and re-use programs. Problems often arise regarding the incompatibility of the structural adhesive with the plastic recycle recovery process. The intrinsic nature of most structural adhesives poses a serious regrind problem, and therefore the adhesive must be cut out of... 

ITW Plexus specializes in the design and manufacture of sophisticated structural adhesives for the bonding of materials used in markets such as transportation, marine, wind energy, automotive, engineering and construction. For more information, visit www.itwplexus.eu. 

Epoxy structural adhesives which employ carboxylic polybutadiene/acrylonitrile solid and liquid (CTBN) elastomers as modifiers have increased in number and proliferated in use since their introduction in the mid- 60 s. Such adhesive systems are now used in aircraft, electronics, automotive and industrial bonding operations. In the mid- 70 s, amine-reactive versions of the liquid polymers (ATBN) were issued, thereby offering another way to introduce rubber modification into a cured epoxy network. References are cited which provide detailed discussions of nitrile rubber, carboxylic nitrile rubber and both carboxyl- and amine-terminated nitrile liquid polymers (1-4). ... 

In the aerospace, aircraft, automotive, electrical, instrument, construction and marine industries, among others, modified acrylics offer distinct assembly advantages over high performance epoxies and urethanes, as well as anaerobic structural adhesives and cyanoacrylates. 

Their J-39 adhesives are room-temperature curable, second-generation acrylics (16). Methyl methacrylate is the monomer, and a nitrile rubber and Dow ABS resin are used as toughening agents. This family of adhesives have been used in automotive, machinery and aerospace structures. Their J-50 adhesives (17) are two-component, fast-cure acrylics. In addition, they also developed a special adhesive, J-15 structural adhesive, for hydroplanes. 

These materials are very much Structural adhesives and as snch are very widely used in Aerospace applications, Automotive applications and elsewhere. 

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