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Why switching to direct drive permanent magnet motor for plastic extruder

2025-07-25 11:50:59

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    What is Plastic Extrusion Systems

    Plastic extrusion systems are industrial setups used to manufacture continuous plastic profiles such as pipes, sheets, films, and more. At the heart of this system lies the extruder—a machine that melts raw plastic materials and forces them through a shaped die to form specific products. This process demands precise control over temperature, pressure, and screw speed to ensure consistent product quality. The motor driving the screw plays a crucial role in maintaining this consistency, making it an essential component of the extrusion system.

    1direct drive permanent magnet motor for plastic extruder

    What is Permanent Magnet Motors

    Permanent magnet motors (PMMs) are electric motors that use permanent magnets embedded in or attached to the rotor to create a magnetic field. Unlike traditional induction motors that rely on induced currents in the rotor, PMMs eliminate rotor losses by using rare-earth magnets like neodymium-iron-boron. The chosen high performance rare earth permanent magnet material and special stator groove and rotor structure make the motor efficiency reach IE4 standard. These motors offer high efficiency, compact size, high torque at low speeds, and excellent speed control capabilities.

    The Concept of Direct Drive Technology

    Direct drive technology refers to a configuration where the motor is directly connected to the driven equipment—such as an extruder screw—without intermediary components like gearboxes or belts. Low speed direct drive high torque permanent magnet motor has motor efficiency above IE4 grade; it has the power factor above 0.96; since it eliminates the reducer transmission, running noise is greatly reduced and installed area is saved. This design minimizes mechanical complexity and enhances energy transfer from motor to application.

    Advantages of Using Direct Drive Permanent Magnet Motors in Plastic Extruders

    2direct drive permanent magnet motor for plastic extruder

    Switching to direct drive PMMs brings several technical benefits tailored for plastic extrusion:

    After adopting Enneng permanent magnet motor, the extruder no longer needs gearbox, coupling, pulley and other devices, which greatly simplifies the structure of plastic extruder and eliminates the maintenance of these components.

    Most permanent magnet motors adopt multi-pole design, which can realize stepless speed regulation and flexibly match the different process requirements of extruders.

    With this motor, the extruder will no longer need gearboxes, couplings, pulleys and other devices, which greatly simplifies the transmission chain structure of the plastic extruder.

    It saves more than 20% of electricity compared to DC motors and more than 15% of electricity compared to AC asynchronous motors.

    These improvements lead to better torque control during startup and operation—critical for consistent product output.

    Economic Implications of Switching to Direct Drive Permanent Magnet Motors

    Although PMMs may involve higher upfront investment compared to traditional AC or DC motors with gearboxes, their long-term financial benefits are substantial:

    • Energy saving is realized by using the new type synchronous drive system.
    • The whole machine efficiency reaches above IE4 standard, which is 5–10% higher than three-phase asynchronous motor efficiency.
    • Power factor can be 1 while asynchronous motors typically reach only about 0.86.

    The combination of energy savings (15–20%), reduced maintenance costs (up to 75%), and improved uptime results in a fast return on investment—often within one or two years.

    Environmental and Operational Benefits

    PMMs not only enhance performance but also contribute positively to environmental goals:

    • Loss will be greatly reduced due to elimination of secondary current so high efficiency can be achieved.
    • Noise is as low as 55 dB.
    • Longevity of the motor: Infinitely reduce the loss of the rotor and temperature rise of the motor is reduced; thus life of bearing is prolonged (compared with asynchronous motor).

    These features improve workplace safety by reducing noise pollution while lowering carbon emissions through decreased energy consumption.

    Factors to Consider Before Making the Switch

    Before transitioning your extrusion system to direct drive PMMs, consider:

    • Compatibility: The motor directly connected to the screw can be customized according to the size of the extruder screw and barrel flange.
    • Voltage & Power Requirements: Voltage Grade: 380V 690V 1140V 8000V 10000V; Power range: 3.7KW–2800KW
    • Control Systems: Synchronous motors cannot be powered by commercial power. Please make sure to connect with output terminal (U,V,W) of frequency converter.
    • Installation Space: While PMMs are compact overall, some types may have different lengths than existing motors.

    Consulting with manufacturers like Qingdao Enneng Motor Co., Ltd., ensures proper customization for your application.

    Future Trends in Motor Technology for Plastic Processing Equipment

    The industry trend leans heavily toward smarter, more efficient systems:

    In future, synchronous motor (permanent magnet built-in) combined with ENNENG frequency converter will replace widely used asynchronous motor + frequency converter as “new generation drive system.”

    Additionally:

    The factory has manufacturing lines for high power permanent magnet motors…which ensures product high quality and large scale production through professional coordination.

    Expect further integration with digital monitoring tools for predictive maintenance and performance optimization.

    Overview of The Plastic Extruder Used Permanent Magnet Synchronous Motors

    3direct drive permanent magnet motor for plastic extruder

    The plastic extruder used permanent magnet synchronous motors offer unmatched advantages over traditional setups by eliminating mechanical complexities such as gearboxes while improving energy efficiency by over 20%.

    With multi-pole designs enabling low-speed high-torque operation below 100 rpm, these motors deliver precise control needed for complex extrusion profiles.

    For companies seeking cost-effective modernization with environmental responsibility in mind—now is an ideal time to upgrade your extrusion systems with Enneng’s permanent magnet solutions. Contact Qingdao Enneng Motor Co., Ltd.at sales@enpmsm.com or visit www.enpmsm.com for tailored consultation.

    FAQ

    Q1: How much energy can I save by switching from AC induction motors?
    You can save more than 15% electricity compared to AC asynchronous motors when using direct drive PMMs in plastic extruders.

    Q2: Are these motors suitable for retrofitting existing machines?
    Yes. The motor can be customized according to screw size and barrel flange dimensions for seamless integration into existing extruders.

    Q3: What voltage levels are supported?
    Voltage options include 380V, 690V, 1140V up to 10kV depending on torque requirements.

    Q4: Do I need a special inverter?
    Yes. Synchronous motors cannot be powered by commercial power; they must be connected via appropriate frequency converters like EN series designed specifically for PMMs.

    Q5: How does it affect maintenance schedules?
    Maintenance needs are significantly reduced due to fewer moving parts—no belts or gearboxes—and robust construction using rare-earth magnets.

    By adopting direct drive permanent magnet technology today, manufacturers position themselves at the forefront of performance-driven innovation in plastics processing.

     

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