Plastic extruder inverter application

Plastic extruder inverter application

We know that most of the screw plastic extruder are generally dc motor driver, but with the development of the society, this kind of equipment to meet the demands of the modern people. So the motor variable speed technology arises at the historic moment. Make it widely used.

Plastic extruder release date on the application of frequency converter: 2012-3-17

Most screw plastic extruder is usually driven by a dc motor, but in recent years, ac motor speed control with its technical and cost advantages, and got more and more applications.

Plastic extruder dc drive

Screw plastic extruder, plastic pellet from funnel heated plasticizing after feeding, the screw rotation to the export of plastic extruder, is decided by extrusion die head shape of the final product. Common characteristic of the single screw plastic extruder screw speed 100 r/min, and mixing with the typical twin-screw plastic extruder speed is 200 ~ 500 r/min, used in profile extrusion of low-speed twin-screw plastic extruder speed is usually 10 ~ 40 r/min.

Traditional plastic 65 extruder needs regular replacement brush, adopted by the dc motor and its resistance to bad environment ability is bad, sometimes also need independent cooling air clean. In everyday use, the typical fault of dc motor brush lighter, armature discoloration, insufficient heat, noise and vibration, etc., make its daily maintenance fee is higher than ac motor, and its cost is also higher.

Plastic extruder ac drives

A few years ago, also cannot provide similar ac drives the excellent properties of dc drive, and expensive. But as in recent years the rapid development of power electronics and microprocessor technology, communication control theory is put forward and the improvement of the communication control software, the ac drive technology in many application fields than dc drive has a better cost-effectiveness. For example, danfoss FC302 series inverter used in plastics extrusion machine, with better speed control performance than dc drive and the torque response speed, among them, the open loop speed control precision is better than 0.5%, the closed-loop speed control accuracy is better than 0.1%.

Because the plastic extruder the starting torque of 65 could reach 200% ~ 250% of its operation torque, 180% than the largest danfoss FC300 series inverter, high starting torque value, therefore, a solution is to choose the larger power drives, another way is that the device rated speed in ac motor constant power region (because of plastic extruding machine at full speed does not need the rated torque of the motor load torque).