Joining mechanisms Bonding, adhesive

Adhesion is basically the joining or bonding of two materials by a third material. There are two primary methods of adhesion, physical or mechanical adhesion and chemical or specific adhesion. 

Adhesive bonding Adhesive bonding uses a separate material at the joint interface, which binds either chemically or mechanically to the substrate. The adhesive may be chemically or thermally reactive or may bond on evaporation of a carrier (water or solvent). Most synthetic or natural fabrics (woven and nonwoven) independent of synthetic fibre content. It can also be used to join garments to nontextile accessories (glitter, foil, etc.). 

Mechanical fastening, adhesive bonding and combinations thereof are the most common techniques for joining FRP pultruded profiles (Zhou and Keller, 2005). 

Thermoset plastics are cross-linked by chemical reaction so that their molecules cannot slip by one anotber. They are rigid when cool and cannot be softened by the action of heat. If excessive heat is applied, thermoset plastics will degrade. Consequently, they are not weldable. Because of their chemical resistance, they cannot be solvent cemented. Thermoset plastics are usually joined by either adhesive bonding or mechanical fastening. Typical thermosetting plastics are epoxy, urethane, phenolic, and melamine formaldehyde. 

Additional details on joining plastics by adhesive bonding, direct heat welding, indirect heat welding, frictional welding, solvent cementing, or mechanical fastening can be found in numerous places. The best source of information is often the plastic resin manufacturers themselves. They often freely offer related recipes and processes, because it is in their interest that their materials successfully find implementation in joined components. 

Oxford Brookes University, Joining Technology Research Unit (A Hutchinson - wide variety of adhesive-related areas including civil structure repair, bonding, and sealing, R Adams - mechanics of adhesive joints)... 

The solvent-borne NR adhesives show an important mechanical component in the bonding process, and therefore bulk mechanical and rheological properties (addition of fillers is quite effective) are important. In fact, these adhesives are mainly suitable when at least one of the surfaces to be joined is water-porous (paper, concrete, leather, textiles). 

Simply bonding a stiffener to a panel with adhesive is certainly a very feasible and natural procedure with typical composite structure construction. We have not discussed any procedure for joining parts except co-curing. Alternatively, to use film adhesive for bonding parts together, we simply cut a sheet or film of adhesive to the proper size, place it between the two parts that we wish to bond together, and then go through a cure cycle that causes the adhesive to adhere to both the stiffener and to the panel itself. We can also mechanically fasten any stiffener we like to a panel. 

Thermosetting resin pipe can be joined with mechanical joints or adhesive-bonded Joints. Mechanical joints are generally a variation of gasketed bell-and-spigot joints and may be either nonrestrained or self-restrained. Adhesive-bonded joints are typically bell-and-spigot or butt-and-strap. Butt-and-strap joints join piping components with multiple layers of resin-saturated glass reinforcement. 

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