| absorption |
A form of adhesive bonding involving the attraction between the molecules of an adhesive and a surface material. |
| adhesion promoter |
A material that helps the adhesive bond to a surface. Adhesion promoters are applied to the surface before the adhesive. |
| adhesive bonding |
The process of binding materials together using any number of adhesive substances. Paste, glue, and tape are examples of common adhesives, while structural adhesives are used for most industrial applications. |
| carrier material |
A material that is mixed with the adhesive and that helps the adhesive wet a surface. Most carriers are either water or a solvent. |
| chemical bonding |
A form of adhesive bonding involving a reaction that results in covalent bonds between the molecules of the adhesive and the surface material. |
| chemical reaction |
A process in which one or more substances are changed into another substance. During a chemical reaction, the physical structure of a substance will alter in some way. |
| chemisorption |
Another term for chemical bonding. The term "chemisorption" is used to emphasize the need for close contact between the adhesive and the substrate. |
| cooling |
The process in which an adhesive physically changes from a liquid to a solid. Cooling occurs when there is a drop in temperature in the adhesive. |
| covalent bond |
A type of atomic bond that occurs when two atoms share electrons. Covalent bonds are relatively strong. |
| creep |
The deformation of a material that occurs over time due to the presence of a constant load. |
| cross-link |
To form primary bonds between polymer molecules. |
| cross-linking |
The development of primary bonds that form between polymer molecules. |
| curing |
The process in which an adhesive undergoes a chemical reaction and becomes a solid. Curing requires pressure, heat, UV light, water, or some other means to initiate the chemical reaction and form the bonded joint. |
| curing agent |
A chemical that induces curing within an adhesive. |
| diffuse |
To transfer material from one object to another due to the migration of atoms. During the drying of some adhesives, the carrier material diffuses into the surface. |
| drying |
A form of adhesive solidification in which either solvent or water evaporates in the air or dissolves into the surface. |
| elastic |
Able to return to its original shape after deformation. |
| elasticity |
The measure of a material's ability to return to its original shape after it has been stretched or deformed. |
| hot melt |
A type of adhesive that requires heat for application and strengthens as it solidifies. |
| mechanical bonding |
A form of adhesive bonding during which adhesive material physically locks into the crevices of the surface. |
| mer |
A basic molecular unit that consists of a collection of atoms. Polymer molecules contain thousands of repeating mers bonded in a long chain. |
| polymer |
A very large molecule consisting of repeating atomic units, or mers. Almost all adhesive materials consist of polymers. |
| primary bond |
A bond that forms between atoms and that involves the exchanging or sharing of electrons. |
| primer |
A liquid material that is used to coat a surface before the adhesive is applied. Primers improve surface conditions and allow for stronger adhesive bonds. |
| solidify |
To change from a liquid to a solid. The bond between surfaces strengthens as the adhesive solidifies. |
| substrate |
The surface material upon which an adhesive is applied to form a bond or joint. |
| surface |
The section of a material to which the adhesive is applied. |
| synthetic adhesive |
A chemically manufactured adhesive derived from either thermoplastics or thermosets. Synthetic adhesives are commonly used in industrial settings. |
| viscoelastic |
Having both viscous and elastic qualities. Adhesives are viscoelastic materials, combining the characteristics of both liquids and solids. |
| viscosity |
A fluid's resistance to flow. The higher the viscosity, the greater a liquid's ability to resist flow. |
| viscous |
Resistant to flow. A liquid that is more viscous is less likely to flow. |
| volatile organic compound |
VOC. A chemical that releases vapors that are harmful to a person's health and the environment. Solvents are used less often as carrier materials for adhesives because they release VOCs. |
| wetting |
The spreading of an adhesive over a surface. Proper wetting occurs when the adhesive fills all crevices and irregularities of the surface. |
| wetting agent |
A material that helps the adhesive spread across the surface. Wetting agents are applied to the surface before the adhesive. |