Application Overview
PET bottles are manufactured using high-speed blow molding machines, a critical process in the packaging industry. Production begins with an injection-molded PET preform, which is then reheated and stretch blow-molded into the final bottle shape using a precision mold.
Because any defect in the preform directly results in scrap and wasted production time, preforms are inspected before the blow molding stage. High-resolution camera systems are commonly used to check critical areas such as the face seal, side walls, and base of the preform to ensure consistent quality.
Technology Requirements
Modern blow molding machines demand highly accurate, synchronised motion control to achieve high output rates and consistent product quality. Typical system requirements include:
- 2–4 servo axes per machine, or alternatively one high-power motor drive with gearbox
- Precise synchronous motion and position control for mold opening, closing, and stretching operations
- High throughput capability, typically ranging from 12,000 to 40,000 bottles per hour
- Fast acceleration and deceleration to support short cycle times and emergency stop conditions
System Configuration
HNC drive and servo products are well suited to blow molding applications and can be configured to meet a wide range of machine sizes and performance levels. Typical solutions may include:
- HV100 / HV480 / HV610 variable frequency drives
- HSD2 / HSD7 servo drives
- SV-E3 servo motors
These components can be combined to deliver reliable, high-performance motion control across the entire machine.
Key Customer Benefits
Using HNC drives and servo systems in blow molding machines delivers several important advantages:
- Integrated closed-loop servo control directly within the drive for improved accuracy and stability
- Excellent dynamic response, supporting rapid acceleration, deceleration, and emergency stop performance
- Angular synchronous operation using an external encoder for precise coordination between machine axes
- Advanced servo stretching technology for high-end machines, where each mold station is driven by its own dedicated servo motor
Conclusion
HNC motion control solutions provide the precision, speed, and reliability required for modern PET blow molding machines. Whether used in standard configurations or advanced servo-stretch systems, these drives help manufacturers maximise output, reduce waste, and maintain consistent bottle quality at high production speeds.
