Exploring the Role of Drives in Extruders

Electric motors are the backbone of almost all industrial applications, driving processes with precision and reliability. The various types of electric motors—AC Induction, DC (Direct Current), and Servo—have unique advantages and specific applications. These motors require sophisticated control mechanisms to ensure optimal performance regardless of the type. This is where drives come into play. Drives, whether AC, DC, or Servo, modulate voltage, frequency and/or current to achieve desired functions like speed, position, and torque control. In industrial settings, drives can operate independently or be controlled by a PLC (Programmable Logic Controller), with many offering advanced features like field bus options and data logging capabilities.

The Vital Role of Drives in Graham Extruders

In the world of extrusion, precision and control are paramount. Most extruders rely on drives to regulate the speed of the screw, ensuring consistent and high-quality output. Drives are not limited to the screw but are also integral to the operation of the rotary blow molding wheel, sheet line take-offs, melt pump assemblies, and conveyors. Essentially, any axis of movement on a machine is likely powered by a drive, making it crucial for the overall functionality and efficiency of the equipment.

Types of Drives and Our Offerings

Typical Types of Drives:

· AC Drives: Ideal for applications requiring precise speed control.
· DC Drives: Known for their simplicity and ability to provide high starting torque.
· Servo Drives: Offer the highest level of precision, often used in applications needing exact position control.

Drives We Use:

At Graham, we typically employ ABB AC Variable Frequency Drives (VFD) and Beckhoff Servo drives. However, our flexibility is one of our strengths—we can integrate virtually any drive manufacturer’s product into our systems based on customer requests. This adaptability ensures we meet diverse needs and preferences, setting us apart from competitors.

Common Issues and Their Causes

Despite their robustness, drives can experience issues over time, especially those subjected to heavy-duty cycles. The most common problems include overheating and defective IGBTs (Insulated Gate Bipolar Transistors). These issues often arise from the following:

· Poor Environmental Conditions: Dust and high humidity can obstruct airflow, leading to overheating.
· Improper Sizing: A drive not appropriately sized for its application can overwork, generating excessive heat.
· Poor Maintenance: Lack of regular maintenance can result in clogged air filters and inadequate cooling.

Impact on Production and Quality

A malfunctioning drive can lead to significant production downtime. Given the long lead times for replacement drives, especially larger ones built to order, such disruptions can be costly. Moreover, drive failures can compromise product quality, making timely repairs or replacements crucial.

Preventive Measures and Maintenance

Adopting predictive and preventive maintenance strategies is essential to mitigate these issues. Predictive maintenance involves monitoring key indicators like vibration, temperature, and operating points to foresee potential failures. Preventive maintenance includes routine air filter checks and ensuring that drives operate in a controlled climate. These steps can significantly extend the life of your drives and enhance their reliability.

Addressing Common Misconceptions

One prevalent misconception is the lead time for replacement drives. Many believe replacements are readily available, but most drive manufacturers build to order, resulting in extended lead times. Another misconception is that quick power cycling—a rapid on/off cycle—does not harm drives. Components need time to discharge, and failure to allow this can cause damage.

Troubleshooting Tips

When troubleshooting, a helpful technique is to determine whether the issue stems from a PLC command or a drive parameter. This can be done by running the drive locally and separating it from fieldbus control. Additionally, comparing and measuring the resistance between each output leg at the drive can help identify defective components.

Life Expectancy of Drives

While there is no definitive answer, the typical life expectancy of a drive is around 10-15 years, though this can vary based on usage and maintenance practices.

Conclusion

Drives are the unsung heroes of industrial machinery, providing the precise control needed for efficient operation. At Graham, our commitment to quality and adaptability ensures that we can meet the diverse needs of our customers, keeping their operations running smoothly. By understanding common issues and implementing effective maintenance practices, you can maximize the lifespan and performance of your drives, ensuring long-term productivity and product quality.

Parts Discount

Reach out to our parts team using the link below. Use the subject line SPOTLIGHT ON DRIVES to receive a discount on the drive you need to run your extruder. The discount is valid for July.

Contact our Parts Team