Sealants are generally chosen for their ability to fill gaps, resist relative movement of the substrates, and exclude or contain another material. Sealants are generally lower in strength than adhesives, but have better flexibility. Usually, a sealant must effectively bond to a substrate in order to perform these functions.
Photopolymer material chemistries were introduced in the 1960s as an alternative to solvent-based material chemistries. Their advantages were so readily apparent that they were quickly adopted for many industrial applications.
Structural bonding in the automotive industry has evolved significantly since its early use in the 1990s. Originally, adhesives were primarily used to complement spot welds to provide sealing and corrosion protection. However, advancements in material chemistry, application and process know-how have led to broader use and dependency upon adhesives to provide body stiffness improvement, body stiffness retention, long-term durability, and improved safety performance.
A 20-story Maryland condo is using high-performance silicone sealants and a unique exterior coating to eliminate water intrusion and provide a new aesthetic appeal to the 30-year-old oceanside building. On a site that some call the windiest building location in Ocean City, the weatherproofing materials play a key role in a $4.1-million rehab designed to protect the building against the salt air and wind-driven rain of the area’s famed “nor’easters,” which have been known to bring torrential rains and 85 mph winds.
Although the growing market acceptance of adhesives as a cost-effective alternative to welding is intriguing to many, companies with roots and expertise in aluminum welding are often skeptical to give glue a go.