Shipper works with N.C. Ports, Maersk to route textile supplies to Central America via Wilmington. By Eric Johnson Frontier Spinning Mills is one of the nation’s largest producers of yarn, and part of a wider textile industry in North Carolina that faces a vexing transportation problem. Sanford, N.C.-based Frontier exports spools of yarn to Central American manufacturing locations, where finished goods are then sent back to the United States as impor...