Epoxy, with its amazing range of applications, has been widely utilized since the 1950’s. Many books were written about epoxy resin and its uses in the 70’s, but since then, numerous changes have occurred in both its chemistry and applications. As of 2006, the epoxy industry amounts to more than $5 billion in North America and about $15 billion worldwide. Today, epoxy users have become more sophisticated and expect more from the products for which they spend their money.
What Exactly is Epoxy Resin?
- Epoxy is a thermosetting polymer formed from the reaction of an epoxide "resin" with polyamine "hardener." Epoxy is used in a myriad of applications, including fiber-reinforced plastic materials and general purpose adhesives. [Thermosetting resin is a material that hardens when heated and cannot be remolded; does not soften when reheated.]
- Epoxy Resins, are a group of synthetic resins commonly used to make plastics and adhesives. They are noted for their high-resistance to chemicals and heat, outstanding adhesion, durability and toughness- which is why they’re valuable as coatings.
Ideal Applications for Epoxy Resin:
- Primers for cars- protects metal from rusting.
- Paint for automotive and marine uses
- Adhesives and glues:
- Used across industries for its strong bonding properties (i.e. automobile, aircraft, road & bridge surfacing, concrete bonding, flooring)
- Bonds permanently to wood, fiberglass, metal, concrete, glass and plastics
- Strong enough to use in place of rivets & welds in industrial applications
- Used in some dental bonding agents
- Protective surface coatings- provide a hard durable and rustproof surface
- Window sills, concrete floors, stair treads, shower stalls, down spouts
- Packaging coatings, can & coil coatings, UV curable coatings, corrosion-resistant composites
- Steel pipes, drain pipes (metal or plastic), pools, roofs, boats, decks & auto bodies
- PVC production- Many vinyl, plastic and PVC products contain epoxy resins (i.e. eyeglass frames, vinyl gloves, handbags)
- Electrical insulation materials to prevent conduction of electricity
- Enclosing transformers, condensers, printed electrical circuit boards and other electrical components
Epoxy is Fundamental in the Following Industries:Functions of epoxy-based materials are extensive across many industries—the resin is utilized in putties, glues, paints, ad infinitum. Many properties of epoxies can be modified (for example silver-filled epoxies crafted for good electrical conductivity).
1. Paints and coatings
Two-part epoxy coatings were developed for heavy-duty employment on metal substrates and use less energy than heat-cured powder coatings. They dry quickly providing a tough, protective coating with remarkable solidity. Their low volatility and water clean- up makes them ideal for factory cast iron, cast steel and cast aluminum. They are usually used in industrial and automotive applications since they are more heat resistant than latex-based and alkyd-based paints.
Polyester epoxies are used as powder coatings for washers, driers and other major household appliances. Fusion bonded epoxy powder coating (FBE) is abundantly used for corrosion protection of steel pipes and fittings used in the oil and gas industry and water transmission pipelines (steel). Epoxy coatings are used as primers to improve the adhesion of automotive and marine paints.
Epoxy adhesives are part of the class called "structural adhesives." This includes polyurethane, acrylic and epoxy acrylate oligomer. These high-performance adhesives are used in the construction of aircraft, automobiles, bicycles, boats, golf clubs, skis, snowboards, and where high-strength bonds are required. Epoxy adhesives can be developed to suit almost any function. They can be used as adhesives for wood, metal, glass, stone, and some plastics. They are more heat and chemical resistant than other common adhesives. Some epoxies are cured by exposure to ultraviolet light. They are then used in optics, fiber optics and dentistry.
3. Industrial tooling and composites
Epoxy systems are used in industrial tooling to produce molds, master models, laminates, castings and fixtures. Epoxies are pivotal for producing fiber-reinforced or composite parts. Many times, they’re even strong enough to be utilized in place of rivets and welds. This plastic tooling replaces metal, wood and other traditional materials. Manufacturers appreciate the fact that epoxy systems lower the overall cost or shorten the lead-time for many industrial processes. They are more expensive than polyester resins and vinyl ester resins, but usually produce stronger and more temperature-resistant composite parts.
4. Electrical systems and electronics
Epoxy resin formulations are important in the electronics industry. They are employed in motors, generators, transformers, switchgear, bushings, and insulators. Because it is an excellent electrical insulator and protects electrical components from short circuiting, epoxy resin is the go-to material to prevent conduction of electricity. Brominated epoxy resins are the primary resins used to make reinforced plastic laminates for printed electrical circuit boards. Their bromine content gives these epoxies improved resistance to ignition. Epoxy resin is also used in overmolding, integrated circuits, transistors and hybrid circuits.
5. Consumer and marine applications
Epoxies are sold in hardware stores, typically as a pack containing separate resin and hardener, which must be mixed immediately before use. They are also sold in boat shops as repair resins for marine applications. Epoxies typically are not used in the outer layer of a boat because they deteriorate by exposure to UV light. They are often used during boat repair and assembly, and then over-coated with conventional polyurethane paint or marine-varnishes that provide UV protection.
Epoxies are used for commercial manufacture of components where a high strength/weight ratio is required. Their strength, gap filling properties and excellent adhesion to many materials (including timber,) have created a boom in amateur building projects such as boats.
6. Aerospace applications
In the aerospace industry, epoxy is used as a structural matrix material which is then reinforced by fiber. The matrix is an aircraft manufacturer's dream come true—a lightweight composite material that you simply apply resins to and lay into a mold. This process automatically produces a lightweight body with a triple skin that has continuous internal ribs and provides superior strength. Epoxies are also used as structural glue. Materials like wood and others that are 'low-tech' are glued with epoxy resin.