Sealant Manufacturers create products used for bonding or filling gaps in substrates and other materials. These products are used in a variety of applications across many industries, including automotive, home improvement, construction, aerospace and more. Unlike adhesives, which are primarily used to attach two materials together, sealants perform distinctive functions that set them apart from other binding substances. These special functions include filling gaps, allowing relative movement between substrates, excluding water and air and containing or exclusion of another material. These functional requirements are why most sealants are classified in a separate category from adhesives.
Modern sealants are generally composed of pliable compounds that bridge gaps and resist a degree of movement or separation between components. They are typically formulated from synthetic elastomeric polymers such as polysulfides, silicones, chloroprene, acrylic, polyurethane and chlorosulfonated polyethylene. Modern sealing formulations also typically include fillers, plasticizers, thixotropic agents, adhesion promoters and curing agents.
The ability to withstand temperature extremes is an important consideration when selecting a sealant. It is also necessary that the product remain durable and retain its properties over a long period of time. Many sealant manufacturers provide a wide range of product options with differing temperature resistance, flexibility and durability characteristics.
It is also essential that the sealant be easy to apply and handle. This can be accomplished through a variety of methods, such as spray-on application systems, primers or two-component sealants that must be mixed to prepare them for use. The ease of handling and application is also often related to the drying time, which must be short enough to allow for quick re-application of the material after it is applied to a surface.
Finally, the performance of the sealant once it is cured is also an important consideration. This includes the depth of cure, which is especially crucial for some types of sealants such as silicones and urethanes that require atmospheric moisture or oxygen to penetrate to the center of the sealant bead for complete curing. Depending on the application, some companies may also select sealants that are designed to provide a specific level of shrinkage during curing.
Adhesive and sealant companies are required to offer a wide range of formulations to meet the diverse needs of their customers. In order to achieve this goal, Sealant Manufacturers must balance the performance needs of the end-user against the cost of production and the availability of raw materials. These factors, in addition to environmental concerns, are critical to the success of any adhesive or sealant product.