Temperature Measurement

Infrared measurement for plastics applications

December 2015 Temperature Measurement

Consistent, accurate temperature measurement is critical in the plastics industry to ensure correct finishing of thermoformed products. In both stationary and rotary thermoforming applications, low forming temperature produces stresses in the formed part; while temperatures that are too high can cause problems such as blistering and loss of colour or gloss.

Thermoforming is the process by which a thermoplastic sheet is made soft and pliable by heating, and bi-axially deformed by being forced into a three-dimensional shape. Heating the thermoplastic sheet is one of the most crucial stages in the thermoforming operation. Thermoforming machines typically use sandwich-type heaters, which consist of panels of infrared heaters above and below the sheet material.

Increasingly the plastics industry is discovering the benefits of non-contact infrared technology for process temperature measurement and control. Infrared-based sensing solutions are useful for measuring temperature under circumstances in which thermocouples or other probe-type sensors cannot be utilised, or do not produce accurate data. Non-contact IR thermometers can be employed to monitor the temperature of fast moving processes quickly and efficiently, measuring product temperature directly instead of the oven or dryer. Users can then easily adjust process parameters to ensure optimal product quality.

Specific advantages offered by infrared technology:

• It is fast, allowing for more measurements and accumulation of data.

• It facilitates measurement of moving targets.

• Measurements can be taken of hazardous or physically inaccessible objects.

• Measurements can be taken in high-temperature environments.

• There is no interference – thus, no energy is lost from the target.

• There is no risk of contamination and no mechanical effect on the surface of the object.

The overall benefits of an automated IR sensing system include:

• Improved part quality.

• Simplified quality control monitoring and setup capability.

• Identification of over-heated or under-heated sheets before making defective (off-spec) parts.

• Ability to thermoform more difficult parts.

• Ability to archive and provide customers with a thermal image of every part manufactured for quality documentation and ISO compliance.

• Increased throughput by reducing part residence time in the heating section.

• Higher yields by significantly cutting down equipment set-up and qualification times.

• Early detection of heater problems affecting process efficiency and energy consumption.

For more information contact R&C Instrumentation, 086 111 4217, info@randci.co.za, www.randci.co.za


Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Pyrometer cooling up to 315°C
September 2021, R&C Instrumentation , Temperature Measurement
The ThermoJacket from Raytek and Fluke Process Instruments gives users the ability to use selected sensing heads in ambient temperatures up to 315°C.

High-speed pyrometer from Optris
September 2021, Instrotech , Temperature Measurement
With very fast processes, the requirements of the pyrometers used for temperature measurement are especially onerous.

Resistance thermometers for hazardous areas
August 2021, Instrotech , Temperature Measurement
Instrotech now offers Kobold’s TWL resistance thermometers with ATEX approvals for ignition protection Exd or Exia.

Thermal imaging in materials testing
July 2021, R&C Instrumentation , Temperature Measurement
The Raytek ThermoView TV40 thermal imaging camera with ThermoView software is an ideal choice for material testing applications.

Vibration-resistant thermowells
July 2021, WIKA Instruments , Temperature Measurement
Debottlenecking is desirable as minor percentage increases in output capacity can result in significant profit returns.

Temperature measuring in steel processing
June 2021, R&C Instrumentation , Temperature Measurement
Accurate and reliable temperature measurement is a part of efficient metal processing and steel manufacturing.

Temperature and humidity monitoring for vaccine rollouts
May 2021, Omniflex Remote Monitoring Specialists , Temperature Measurement
How remotely monitoring facilities maintains the vaccine cold chain.

High-temperature pyrometer with Bluetooth
May 2021, R&C Instrumentation , Temperature Measurement
Raytek has added Bluetooth capability to the Raynger 3i Plus handheld pyrometer.

Automated cold chain monitoring
March 2021 , Temperature Measurement
Smart, connected and automated temperature monitoring at every point helps logistics companies proactively ensure their cold chain is never broken and goods arrive in prime condition for use and sale.

Accuracy of infrared temperature measurement
March 2021, R&C Instrumentation , Temperature Measurement
Infrared (IR) thermometers have the ability to measure temperature without coming into physical contact with a particular product.