Handbook of Adhesives and Sealants

22 Chapter Oneallurgically incompatible materials, thermoset plastics, ceramics, elastomers,thin materials, or very small parts. Adhesive bonding is alsogenerally appropriate when there are large areas to join, or when adhesivescan be chosen to provide improvement in manufacturing productivity.Usually the decision of which fastening method to use involves severaltrade-offs. A trade-off analysis, as shown in Table 1.6, can beuseful in identifying potential fastening methods. When this is performed,the possibility of using adhesives over other methods becomesapparent.The science of adhesive bonding has advanced to a degree whereadhesives must be considered an attractive and practical alternativeto mechanical fastening for many applications. Adhesive bonding presentsseveral distinct advantages over conventional mechanical methodsof fastening. There are also some disadvantages which may makeadhesive bonding impractical. These pros and cons are summarized inTable 1.7.The design engineer must consider and weigh these factors beforedeciding on a method of fastening. However, in some applications ad-TABLE 1.6 How Joining Methods Compare 5Riveting Welding BrazingAdhesivebondingPreliminary machining P E P EWith thin metals P P F ELimits on metalF P P EcombinationsSurface preparation E G F PTooling E F F FNeed for access to joint P P E EHeat requirements E P P F–GStress distribution P F–G E ESealing function P F E GRate of strength development E E E PDistortion of assembly F P F EFinal machining G–E F E EFinal heat treatment E F F ESolvent resistance E E E FEffect of temperature E E E PEase of repair G P P FLevel of skill required E G E ENOTES: E—Excellent, G—Good, F—Fair, P—Poor.