FRP Tanks
Tanks are often manufactured from fiberglass reinforced plastic, a combination of plastic and resin. They exhibit light weight, high strength, long life and rust and chemical resistance. FRP is an FDA approved material, and is therefore used in many food processing applications. It can also hold potable drinking water. Fiberglass reinforced plastic is a composite material made of fiberglass, carbon or aramid, and a polymer made from epoxy, vinyl or polyester. FRP tanks are the most popular option for underground fuel storage, pulp bleaching and chemical processing. They also often store chemicals that corrode or interact with non-resin materials like stainless steel. Although they are inexpensive, FRP tanks are also difficult to repair if damaged, when compared to other plastic tanks.
Fiberglass reinforced plastic products, including tanks, are manufactured via the contact molding process. These tanks are so strong because they are composed of multiple layers of many different kinds of materials. First, a mandrel in the shape of the tank is sprayed with resin on its outer surface. Reinforcements are then added. A corrosion layer is sprayed on and mat or fabric is added as well. After curing, structural layers are applied along with the resin, and once dried, the mandrel (mold) is separated from the newly formed FRP tank. FRP tanks often have long axis. Vertical tanks are usually used above ground, while horizontal are used underground and for transportation of liquids and chemicals.