Use of Adhesive

The physical and chemical properties of both the solidified adhesive and the polymer affect the quality of the bonded joint. Major elements of concern are the corrosion resistance of the adhesive, its thermal expansion coefficient, and the glass transition temperature of the polymer relative to the adhesive. 

Large differences in the thermal expansion coefficient between the polymer and adhesive can result in stress at the polymer s joint interface. 

Temperature limits may have to be modified depending upon the corrodent if in direct contact. 

ABS Methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, methylene 

Acetate Methylene chloride, acetone, chloroform, methyl ethyl ketone, ethyl 

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Bonded Solid-Film Lubricants. Although a thin film of soHd lubricant that is burnished onto a wearing surface often is useful for break-in operations, over 95% are resin bonded for improved life and performance (62). Use of adhesive binders permits apphcations of coatings 5—20 p.m thick by spraying, dipping, or bmshing as dispersions in a volatile solvent. Some commonly used bonded lubricant films are Hsted in Table 12 (62) with a more extensive listing in Reference 61. 

Ceramics are joined to metals by metal eoating and brazing, and by the use of adhesives. In metal coating, the mating face of the ceramic part is coated in a thin film of a refractory metal such as molybdenum (usually applied as a powder and then heated). 

The chemical bonding theory of adhesion applied to silicones involves the formation of covalent bonds across an interface. This mechanism strongly depends on both the reactivity of the selected silicone cure system and the presence of reactive groups on the surface of the substrate. Some of the reactive groups that can be present in a silicone system have been discussed in Section 3.1. The silicone adhesive can be formulated so that there is an excess of these reactive groups, which can react with the substrate to form covalent bonds. It is also possible to enhance chemical bonding through the use of adhesion promoters or chemical modification of the substrate surface. 

The aerospace field is a broad one and has a complex history. A comprehensive review of structural adhesive applications on currently flying aerospace vehicles alone could fill its own book. Hence this chapter will concentrate on the aerospace commercial transport industry and its use of adhesives in structural applications, both metallic and composite. Both primary structure, that is structure which carries primary flight loads and failure of which could result in loss of vehicle, and secondary structure will be considered. Structural adhesives use and practice in the military aircraft and launch vehicle/spacecraft fields as well as non-structural adhesives used on commercial aircraft will be touched on briefly as well. 

While the use of adhesive bonding is widespread among all aerospace firms, the author is most familiar with history and practice at The Boeing Company and will of necessity draw primarily on that resource. Adhesive bonding use at other firms will be included as much as possible. 

Knight, G. M. (1984). The use of adhesive materials in the conservative restoration of selected posterior teeth. Australian Dental Journal, 29, 324-31. 

The use of adhesives, such as nicotine-bentonite-oil or lead arsenate-Bordeaux-oil, increased the DDT residues at harvest. 

Films are supplied with one or both sides pre-treated to enable the use of adhesives such as acrylics, polyesters, epoxies, rubbers and pressure-sensitive mastics. 

Wake, W.C. (1978). Theories of adhesion and uses of adhesives A review. Polymer 19, 291-308,... 

Rechak, S. and Sun, C.T. (1990). Optimal use of adhesive layer in reducing impact damage in composite laminates. J. Reinforced Plasl. Composites 9, 569 582. 

Bond - The union of materials by use of adhesives, usually used in relation to parts vulcanized after attaching or being assembled together. 

The best approach to achieving good performance in bonded joints is to select the proper adhesive, design the joint properly for the specific application, and maintain rigid process control. One disadvantage in the use of adhesives is the absence of good non-destructive tests to determine the strength of adhesive-bonded joints in a wide variety of ord applications... 

The use of adhesives to bond plastics to each other and to other substances— such as metals, paper, and wood—is long-established and may well pre-date even the simpler techniques for joining these materials by applying heat in... 

Adhesives offer both advantages and disadvantages in comparison with other methods of assembly, some of the most important of which are presented in summary form at the conclusion of this chapter. (The chapter as a whole comprises an introductory section, a summary of theoretical considerations underlying the effective use of this approach, a review of the types and typical compositions of adhesives suitable for bonding plastics ( solvent-based , water-based , hot-melt , and reactive ), requirements and methods for treating the surfaces in preparation for bonding, and a number of examples of the successful use of adhesives.)... 

In the electrical and electronic equipment market, adhesives compete with other joining methods such as mechanical fasteners, brazing, welding, soldering, and thermocompression bonding. Major uses of adhesives in the electrical and electronic equipment market are shown in Table 1.5. Adhesives are generally the preferred method of joining whenever... 

However, even with these potential difficulties, adhesive bonding can be an easy and reliable method of fastening one type of plastic to itself, to another plastic, or to a nonplastic substrate. Pocius et al. provides an excellent treatise on the use of adhesives in joining plastics.51... 

Certain specifications and standards provide excellent tutorials on adhesives and sealants. For example, MIL-HDBK-691 offers a complete handbook on adhesive bonding, and MIL-HDBK-725 provides a guide to the properties and uses of adhesives. ASTM C 962 provides an excellent source of information regarding sealant joint design and the types of sealants that are appropriate for various substrates. Although this specification is primarily for construction sealants, much of the information that it contains is generally useful for other sealant applications. 

D 4896 Guide for the Use of Adhesive Bonded Single Lap-Joint Specimen Test... 

Textiles, as are many objects of art, are subject to the deteriorative effects of dirt, acidity, light, humidity, and mishandling. The steps by which they are conserved are detailed, including a discussion of the problems inherent in their restoration. The use of the vacuum hot table—a recent technique—is exemplified in the treatment of embroideries and two Civil War flags, and the use of adhesives is discussed in regard to this technique. 

Any bonded construction consists of at least two adherends and one adhesive and contains at least two interphase regions. It is important to remember that the performance of the construction, its durability, its mechanical properties, and its response to tests and challenges, are all properties of the entire assembly. The successful use of adhesives depends on taking account of all parts of the construction and the process. Whereas the adhesive is just one part of the assembly, its chemistry plays an important role in the bonding process. 

The successful use of adhesive joining in producing any assembly depends on viewing... 

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