Applied to the production of PET and PLA sheets, without the need for a pre-crystallization drying system, and can be adapted for recycled material production, featuring high throughput, low energy consumption, and excellent plasticization. The screw adopts a modular building-block structure with multiple combinations and a wide application range; it is not only suitable for PET production, but also suitable for PLA fully biodegradable materials and starch-based degradable materials. The barrel is equipped with dual vacuum venting to ensure full discharge of water vapor. The extruder is equipped with a melt metering pump for metered, pressure-stabilized output, and closed-loop automatic control of equipment pressure and speed. The entire machine adopts PLC control to achieve automated control of functions such as parameter setting, data calculation and feedback, and alarms.