Thermosetting polymers are usually liquids or malleable solids until curing. During this process, the polymer chains form cross links between them and solidify. Once cured, the polymer has typically become a solid with a melting point higher than its decomposition temperature. This means that the resulting material cannot be melted back into its original form, unlike a thermoplastic. Curing usually occurs either above a particular temperature, when mixed with another polymer, or irradiated.