A thermoplastic is a type of plastic made from polymer resins that becomes a homogenized liquid when heated and hard when cooled.
As similar as colonial iron manufacture was to that of medieval Europe, yet it differed greatly from the type of iron manufacture in eighteenth century early modern Europe. Existing conditions of natural resources greatly affected the development of technical innovation in the field of iron manufacture.
Ironworking had evolved in East Africa before the rise of the city states. They improved the process and produced iron objects for trade as well as local use. Archaeology studies provide evidence that the city states carried on a flourishing long distance trade with Persia, India, and China.