Automotives bonding

One-component waterborne urethanes are used as packaging adhesives and tie coats and for automotive bonding of PVC. 

During World War II, synthetic rubber and resin-modified phenolics were used to bond aluminum sheets (available only in in. thickness at that time) into billets from which airplane propellers were carved, thus replacing laminated wood, which often shattered on impact with a bullet. Similar adhesives were used to bond rubber to metal in a variety of vibration-damping applications. The most successful widely known product of the new technology was the automotive bonded brake lining first introduced in 1947, and now regarded as a symbol of quality and integrity [12, p. 490]. 

Silicone PSA products are used in a number of medical and industrial appKcations, ranging from a variety of PSA tapes and transfer films to automotive bonding. Advantages for the silicone PSA products include resistance to temperature extremes, chemical resistance, conformity to irregular surfaces, and electrical properties. They are also unique to most PSAs in their ability to adhere to difficult low-energy substrates, such as polytetrafluoroethylene and other silicones. 

The same (or a very similar) silane process can be used for many other automotive and non-automotive bonding applications, such as engine mounts. 

Typical Use Automotive. Bonding of body panels. Typical Use Automotive. Bonding of body panels. ... 

Ripling EJ, Mostovoy S et al (1964) Measuring fracture toughness of adhesive joints. N terials Research Standards (ASTM Bulletin) 4(3, March) 129-134 Swadener JG, Liechtiet KM et al (1999) Mixed mode fracture of automotive bonded joints. SAMPE-ACX2E-DOE Advanced Cpmposites Conference. Detroit MI... 

The principal type of shear test specimen used in the industry, the lap shear specimen, is 2.54 cm wide and has a 3.23-cm overlap bonded by the adhesive. Adherends are chosen according to the industry aluminum for aerospace, steel for automotive, and wood for constmction appHcations. Adhesive joints made in this fashion are tested to failure in a tensile testing machine. The temperature of test, as weU as the rate of extension, are specified. Results are presented in units of pressure, where the area of the adhesive bond is considered to be the area over which the force is appHed. Although the 3.23-cm ... 

Adhesives. Contact adhesives are blends of mbber, phenoHc resin, and additives suppHed in solvent or aqueous dispersion form they are typically appHed to both surfaces to be joined (80). Evaporation of the solvent leaves an adhesive film that forms a strong, peel-resistant bond. Contact adhesives are used widely in the furniture and constmction industries and also in the automotive and footwear industries. The phenoHc resins promote adhesion and act as tackifiers, usually at a concentration of 20—40%. In solvent-based contact adhesives, neoprene is preferred, whereas nitrile is used in specialty appHcations. The type and grade of phenoHc resin selected control tack time, bond strength, and durabiHty. 

Despite their higher cost, tin babbitts are often preferred over lead for their excellent corrosion resistance, easy bonding, and less tendency for segregation. SAE 12 (ASTM Grade 2) is widely used in both automotive and industrial bearings (13) ASTM Grade 3 and SAE 11 also find extensive industrial use. 

Wear. Eor a fixed amount of braking the amount of wear of automotive friction materials tends to remain fairly constant or increase slightly with respect to brake temperature, but once the brake rotor temperature reaches >200° C, the wear of resin-bonded materials increases exponentially with increasing temperature (26—29). This exponential wear is because of thermal degradation of organic components and other chemical changes. At low temperatures the practically constant wear rate is primarily controlled by abrasion, adhesion, and fatigue (30,31). 

Highly saturated nitrile elastomers (HSN) have become available. These mbbers are prepared by (nearly complete) hydrogenation of the nitrile mbber copolymer. The resulting product has better heat and oxidation resistance than conventional nitrile mbber but still retains some double bonds for vulcanization. Trade names for HSN are Zetpol (Nippon Zeon), Therbar (Bayer), and Tormac (Polysar). HSN has been used, and is being developed, for oil field chemical, automotive, power station, aerospace, military, and industrial appHcations (66). 

The hydrogenated materials have a higher maximum service temperature than the conventional SBS materials and, because of the absence of double bonds in the chain, better weathering properties. Known as SEBs these materials now find use in adhesives, sealants and roofing membrane compounds. These also find use in highly filled automotive acoustic barriers and in medical, sports and leisure applications. 

Large-scale adhesive bonding of steel is of great interest to the automotive and appliance industries because of the opportunities it provides for design flexibility, weight savings, and manufacturing economy. Because of its economic importance. 

Another important application of NR is for bonding ceramic tiles, although it needs special compounding with clay filler and cellulose thickener. Water-borne NR adhesives can also be used for bonding canvas and leather shoes and interior trim in some automotive applications. 

Solvent-borne CR adhesives allow almost any two substrates to stick together. The adhesives are extensively used in bonding high-pressure plastic laminates, automotive adhesives, adhesives for construction and shoe adhesives. 

Automotive adhesives. CR adhesives are used to bond recreational vehicle sidewalls, for vinyl trim bonding in panels, and to bond in place truck and trailer roofs. 

Several large applications for one-component moisture-cure urethane adhesives are available. Polymeric MDI is an exceptional binder for wood products, such as oriented strand board and particleboard. One-component urethane windshield adhesives are used almost exclusively in both the OEM and automotive aftermarket. One-part urethane adhesives are used to assemble the sidewalls for recreational vehicles (RV s), manufactured housing, and mobile homes. In construction applications, one-part urethanes are used to bond metal doors, hardwood flooring, panels, and partitions. 

Solvent-home urethanes are still widely used to bond leather and athletic shoes. The OEM automotive market uses some solvent-home urethanes together with chlorosulfonated polyethylene as a primer. Some urethane solvent-home packaging adhesives are used for cap liners and for paper and foil lamination. Some textile laminating applications are still based on solvent-home urethanes. 

Two-component urethane adhesives are used to bond sheet molding compound (SMC) panels for automotive OEM and aftermarket applications. Two-part urethanes are used as laminating adhesives in the RV industry. 

Acrylic adhesives can also be used in automotive assembly. For example, the hem flanges between the inner and outer panel of automotive doors can be bonded with acrylic adhesives [153]. There are many smaller industrial assembly applications where acrylic adhesives are applicable. An interesting recent example is the bonding of cable splice enclosures, using a borane initiated adhesive [154]. 

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