Adhesive bonding benefits

De Bruyne himself was undoubtedly no small factor in the spread of adhesive bonding through the European aerospace community. In addition to co-inventing the Redux family of adhesives, he was involved in the conceptual development of the Mosquito and numerous other aircraft and sponsored (and taught) a series of educational sessions on the benefits of structural bonding during the post-war years. 

One of the benefits of surface treatment prior to adhesive bonding is that it not only removes weak boundary layers such as contamination, but also provides a more consistent surface to which the adhesive can bond. Common surface treatments used for metal substrates are characterized generally in Table 16.2. 

One of the most frequent procedures in the formulation of adhesives is the addition of adhesion promoters. Of these, silanes are by far the most frequently used. The silanes form a multi-membered family of chemicals. Numerous publications have described aspects of silane chemistry and the applications of silanes [15-18]. Although many silanes are readily available, in many industrial formulations of adhesives the most frequently used of these are the primary amine and diamine versions because of their relatively low cost. However, these do not necessarily produce optimum benefits in adhesion for all applications. Guidelines for the selection of silanes best suited for specific applications would therefore be useful. These should be based on a fundamental understanding of the manner in which silane compounds affect the interface and interphase in adhesively bonded systems. The... 

The adhesive joint should be designed to optimize the forces acting on and within the joint. Although adequate adhesive bonded assemblies have been made from joints designed for mechanical fastening, maximum benefit can be obtained only in assemblies specifically designed for adhesive bonding. 

Adhesive properties are of significant importance in optimizing bond-line thickness. To take advantage of adhesive ductility, increased adhesive thickness can increase the volume of material within which energy is dissipated. Brittle adhesives normally benefit little from increased bond-line thickness ductile adhesives often perform better with slightly thicker bondlines. 

One of the benefits of using structurai adhesive bonding is that different metais can be joined together. For exampie, in the assembiy of bicycie frames, the aii steei construction needed for the brazing technique has been repiaced to provide iighter... 

The added benefits of the unique functionality of the hydrogels involve increased dentin adhesive bond strengths (after 24 h and after 6 months) and positive influence on the nystatin and aspirin release. Overall, there was an insignificant relapse in the shear bond strength after 6 months. This approach highlighted the importance of iimo-vative development of functional dental restorative material with bioactive and bonding properties suitable for use in dentin and enamel. 

In the first volume, we focused on adhesion with or without the use of an adhesive, and we were chiefly concerned with mechanisms of bond formation. In this volume, we are interested in both bond-forming and bond-breaking processes. Since polymeric adhesives will be at the center of our discussions, we need to know their physical properties as well as their related measurements. After we apply an adhesive to an adherend, we must understand how to determine bond strengths. With data on hand, we should also learn how to analyze the test results and make certain predictions about the durability of adhesive bonds. Though the entire process sounds rather difficult, we hope that readers will find this volume of benefit. 

The most common Ultrasonic Bond Inspection Procedures are illustrated in Fig. 4. Each has its special benefits for solving specific adhesive bonding inspec-... 

Epoxies cure to become thermoset adhesives and so show excellent humidity resistance, especially if one of the substrates is metal. For long-term, durable adhesively bonded metal-to-metal joints, toughened epoxies are hard to beat [6] but where plastics are involved, some of the other technology adhesives invariably offer benefits in terms of ease of application and cure speed whilst still retaining satisfactory environmental resistance. Indeed epoxies do not often show good adhesion to elastomers and for the thermoplastic elastomers cyanoacrylates will generally show the best environmental resistance. 

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