glueadhesive

Glue and adhesives are substances used to bond two surfaces together. They come in many forms and are designed to create a lasting join by chemical or physical bonding. The term glue is often used for traditional, protein- or animal-based products, while adhesive is a broader term that includes synthetic polymers and reactive systems.

Common adhesive categories include natural adhesives (starch, casein, animal glue) and synthetic adhesives (epoxy, polyurethane, cyanoacrylate, acrylics, silicone, polyvinyl acetate). Curing mechanisms vary: some dry or evaporate solvents, others cure chemically at room temperature, with heat, or via moisture. Some are two-part systems that polymerize from a hardener and resin.

Adhesives are selected based on substrate compatibility, required strength, flexibility, thermal resistance, and environmental exposure. They are used on wood, metal, plastics, glass, textiles, and composites. Performance characteristics include shear and peel strength, gap-filling ability, and resistance to moisture, temperature, and chemicals. Cure times can range from seconds to days.

Applications span construction, packaging, woodworking, automotive, electronics, and medical devices. Safety and environmental considerations include volatile organic compounds, potential skin sensitizers, and proper storage to prevent premature cure. Handling guidelines emphasize ventilation, gloves, and eye protection.

History and standards: bonding with glues has ancient roots, with modern adhesives developing through the 20th century to support diverse industrial uses. Standards and testing from organizations such as ASTM and ISO provide performance criteria to ensure consistency, safety, and interoperability across products.