The die head adopts an extension V shape water-drop type flow channel, with the shunt technology and special triangle stabilize structure. To composite layer and improve the precision of the extrusion process to eliminate 'M' shape and 'W' shape flow patterns effectively. The upper die lip using push-off type manual fine-tuning + automatic fine-tuning one-piece die lip, manual adjustment range is ±1mm, automatic adjustment range ±300um; About the automatic die lip adjustment control parts ,we use currently very advanced fully closed loop control system and the automatic gauging system makes the product thickness in±2% precisely.