High-speed plastic molding processes, such as Injection Stretch Blow Molding (ISBM), require precise and reliable temperature control to ensure consistent product quality. In mass production environments, even minor temperature deviations during preform heating can lead to structural defects, uneven wall thickness, or product failure.
To maintain stability and efficiency, manufacturers increasingly rely on non-contact infrared measurement technologies that provide real-time temperature data and enable immediate process adjustments.
Process Characteristics and Measurement Challenges
Injection Stretch Blow Molding is a two-stage process. First, preforms are produced through injection molding. These preforms are then reheated and stretched into their final shape using compressed air.
The heating stage is critical:
• preforms must reach an exact temperature for proper stretching
• insufficient heating leads to incomplete forming or thick areas
• overheating results in weak spots and reduced mechanical strength
• high production speeds demand extremely fast measurement
In modern production lines, where thousands of units are produced per hour, traditional measurement methods are not fast or precise enough to ensure consistent results.
Infrared Measurement as a Solution
Infrared pyrometers provide a reliable, non-contact method for monitoring preform temperature during the heating stage. These sensors enable continuous, real-time measurement without interfering with the process.
By integrating infrared sensors into molding machines, manufacturers can:
• monitor temperature of each preform during heating
• detect deviations instantly
• adjust heater output automatically
• maintain uniform temperature distribution
This ensures optimal conditions for forming high-quality plastic products.
Optris Solutions for High-Speed Molding
Optris offers advanced infrared pyrometers specifically designed for fast and demanding industrial processes such as ISBM.
Optris CTfast
The CTfast pyrometer is designed for ultra-fast temperature measurement in high-speed production environments.
Key features:
• response time as fast as 6 milliseconds
• temperature range from –50 °C to 975 °C
• high sensitivity for detecting rapid temperature changes
• ideal for dynamic processes with moving objects
This makes the CTfast particularly suitable for monitoring preforms in fast conveyor-based systems where timing is critical.
Optris CT 4M
The CT 4M offers even faster response and is optimized for plastic materials with varying emissivity.
Key features:
• ultra-fast response time of 90 microseconds
• temperature range from 0 °C to 500 °C
• spectral range of 2.2 – 6 µm, ideal for plastics
• compact sensing head (14 mm diameter) for tight installation spaces
Its spectral characteristics ensure accurate measurements even when material properties vary during heating.
Integration into Production Systems
Both CTfast and CT 4M pyrometers are designed for seamless integration into industrial environments.
Key integration capabilities include:
• real-time data transmission to PLC systems
• support for industrial protocols such as Modbus TCP and Ethernet/IP
• automatic control of heating systems based on temperature feedback
• compact design for installation inside molding equipment
This allows manufacturers to fully automate temperature control and maintain stable process conditions.
Advantages of High-Speed Infrared Measurement
The use of fast-response infrared sensors provides several important benefits:
• improved product quality through consistent preform heating
• reduced scrap rates caused by temperature deviations
• increased production stability at high operating speeds
• immediate detection and correction of process variations
• minimized downtime and production interruptions
Additionally, the non-contact nature of infrared measurement ensures long-term reliability and low maintenance requirements.
Application Value in Industrial Production
Advanced thermal measurement transforms plastic molding processes into highly controlled and optimized operations.
With infrared pyrometers such as CTfast and CT 4M, manufacturers can:
• achieve uniform material distribution and wall thickness
• maintain consistent product quality across large production volumes
• optimize energy usage by controlling heating precisely
• enhance overall production efficiency and output
As a result, high-speed molding processes become more reliable, cost-effective, and aligned with modern manufacturing standards, including automation and Industry 4.0 requirements.
