Adhesives categories

In O Sect. 12.4, the physical form of adhesives is used for classification purposes and specific adhesives are discussed for each class of adhesives to provide more insight on adhesive categories including chemical families. This is because, many adhesives have cross-category characteristics, as already illustrated with some of the above listed adhesive examples. Additional examples are epoxies, which are typically listed as structural adhesives, but are also available in elastomer-epoxy forms high-temperature thermoplastic polyimide adhesives. 

In the category of industrial appHcations, nylon is the predominant fiber used in the carcass of bias tmck, racing car, and airplane tires because of its exceUent strength, adhesion to mbber, and fatigue resistance. Nylon is used less in the carcass of radial tires for automobiles and in replacement bias and bias-belted tires because of the development of temporary flat spots. For this reason, nylon has lost most of this market to polyester. 

The intermolecular forces of adhesion and cohesion can be loosely classified into three categories (7) quantum mechanical forces, pure electrostatic... 

Adhesive Transfer Processes. Many polymers, whether dehberately or accidentally, are adhesives, so that much of the adhesive industry can be regarded as a part of the mbber and plastics industry. However, there are several important material-transfer appHcations involving polymer products that are so critically dependent on controlled adhesion that they merit specific mention in that category. They include hot stamping foils, release coatings for pressure-sensitive adhesive products, photocopier materials, transfer coatings, and transfer printing of textiles. 

The second category was concerned with adhesion to porous or microfibrous surfaces on metals. Aluminium may be anodised to form an oxide surface comprising pores of diameter of tens of nanometers. Electroforming and chemical oxidation can be used to produce microfibrous or needle-like coatings on metals, including copper, steel and titanium. The substrate topography was demonstrated to play an vital part in adhesion to these surfaces [45-48]. 

The primary non-woven applications for hot melts are in disposable articles such as diapers and sanitary napkins (see Fig. 22). These articles are made by high speed processes and are immediately packaged in sealed plastic bags, thus they are prime candidates for hot melt use. The applications are broken down into three categories, requiring three different types of adhesives construction, elastic attachment, and garment attachment. 

Urethane adhesives are classified as one-component or two-component adhesives. Each category includes several different types of adhesives. 

Of the commercially available EB-curable adhesives [9-12], the resins fall within one of two categories based on their curing mechanisms. The majority of EB-curable resins are based on (meth)acrylate-functionalized oligomers involving a free-radical curing mechanism. The second category is the epoxy resins that cure by a cationic mechanism. 

There are, however, certain materials used as ingredients in the manufacture of plastics, which almost invariably give a corrosive product. Included in this category are wood, which is frequently used as a filler or as part of a composite drying oils, used in paints, adhesives, jointing compounds and linoleum and esters of volatile acids frequently retained in certain cold setting formulations, especially some paints. ... 

In a comprehensive study of trichloroethylene emission sources from industry conducted for EPA, the major source was degreasing operations, which eventually release most of the trichloroethylene used in this application to the atmosphere (EPA 1985e). Degreasing operations represented the largest source category of trichloroethylene emissions in 1983, accounting for about 91% of total trichloroethylene emissions. Other emission sources include relatively minor releases from trichloroethylene manufacture, manufacture of other chemicals (similar chlorinated hydrocarbons and polyvinyl chloride), and solvent evaporation losses from adhesives, paints, coatings, and miscellaneous uses. 

Hexane is contained in a variety of products commonly used in household settings. Given its volatility, this creates possibilities for exposures from inhalation as well as by dermal contact and ingestion. In a study of over 1,000 common household products, -hexanc was detected in 101 products, about the same detection rate as for BTEX compounds (e g., benzene, toluene, xylene or ethylbenzene) and other normal alkanes. -Hexane was detected in more than 10% of the items sampled in the following product categories automotive products oils, greases and lubricants and adhesive-related products (Sack et al. 1992). 

Residual products (No. 6 fuel oil, bunker C oil) these products have little (usually, no) ability to evaporate. When spilled, persistent surface and intertidal area contamination is likely with long-term contamination of the sediment. The products are very viscous to semisolid and often become less viscous when warmed. They weather (oxidize) slowly and may form tar balls that can sink in waterways (depending on product density and water density). They are highly adhesive to soil. Heavy oil, a viscous petroleum, and bitumen from tar sand deposits also come into this category of contaminant. 

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