Selecting the right plastic requires balancing mechanical properties, thermal stability, and chemical resistance. For high-strength industrial parts, prioritize Engineering Plastics like Nylon (PA6/PA66) or Polycarbonate (PC). For packaging and general consumer goods, Polyethylene (PE) and Polypropylene (PP) offer the best cost-efficiency. Always verify the Melt Flow Index (MFI) to ensure compatibility with your specific manufacturing process, whether it is injection molding, extrusion, or blow molding.