Memory foam is produced in a complex multi-step process that takes several hours. Liquid chemicals are transported to the manufacturing facility in large tanks where they are mixed according to the proprietary formulas. The reaction process is called polymerization. After that the mass is poured into a mold on conveyor belt where it rises and cures. Then the foam is let to rest for several hours to allow proper curing. After curing is complete, the foam is trimmed into desired sizes.