Haomei realizes quality control of its aluminum trim cap coil through aluminium stocks, process, stretch bending and instant quality inspection. The stocks for aluminum cap coil must have a medium crown of 0.2-0.8% and longitudinal thickness difference not more than 0.1M. The surface of the blanks should be free from cracks, bubbles, pores, corrosion, peeling, periodic marks, metal and non-metal …