2026-07-24
Select the adhesive based on the type of bonded joint.
1. Mechanical Strength
Adhesives of this type should possess good mechanical strength, including tensile strength, shear strength, and peel strength. Epoxy resin adhesives are commonly used but often exhibit poor peel strength; however, satisfactory results can be achieved by using epoxy-nitrile or phenolic-nitrile blends. For repairing worn machine tool guideways, wear-resistant adhesives are required—such as AR-5, which has a hardness of 11.8 HB and consists of epoxy resin and inorganic fillers. In contrast, adhesives for plastic carpeting or beverage bottle labels require high shear strength but low peel strength.
2. Heat Resistance
Generally, the long-term service temperature for polymer adhesives is below 200°C. However, certain specialized applications demand long-term service temperatures exceeding 200°C. Examples include adhesives for microelectronic components that must bond to substrates at 400°C in an inert atmosphere; structural adhesives for supersonic aircraft that must withstand service temperatures of 230°C for tens of thousands of hours; and adhesives for missiles that must maintain their mechanical properties for over one minute at 540°C. These represent specialized adhesives designed for unique applications.
3. Oil resistance
Bonding applications for oil pipeline joints and components exposed to lubricating oil require adhesives that can achieve sufficient bond strength in oily and humid environments, even when surface pretreatment is not feasible.
4. Water resistance
Generally, polar adhesives are highly hydrophilic; consequently, bond strength tends to drop sharply in humid environments.
5. Optical properties
Adhesives used for optical components must not only provide adequate bond strength but also meet specific light transmission requirements—typically exceeding 90%.
6. Other functions
Bonded joints may be required to fulfill a wide variety of functions, such as electromagnetic properties, acoustic performance, or physiological effects.