elastics

Elastics, in common usage, refer to materials that can be stretched or deformed and then return to their original shape. In materials science, elasticity is the property of a material to resist deformation and recover its shape after the removal of a force. Elastics are typically polymeric networks called elastomers, with natural rubber being the classic example; many synthetic elastomers such as styrene-butadiene rubber (SBR), neoprene, silicone, and polyurethane are used.

Elastics owe their properties to cross-links between polymer chains established during vulcanization or other curing processes. Cross-link density controls stiffness, elasticity, and temperature dependence. Elastomeric materials can be molded, extruded, or formed into fibers, films, or bands and may include fillers to enhance strength.

Common applications include clothing and textiles (waistbands, cuffs, socks), medical and sports supports, and orthodontic elastics that attach to braces to guide tooth movement. In engineering, elastics are used as seals (O-rings), vibration dampers, tires, and springs.

History and safety: The modern rubber industry began with vulcanization, discovered by Charles Goodyear in 1839, which improved elasticity and durability. Natural rubber can cause allergic reactions in some people, and elastics may degrade with heat, ozone, UV light, or aging; proper storage extends life.