Temperature Measuring in Plastics Processing with Infrared Radiation Thermometers

Obendrauf, W.; Langecker, Günter; Friesenbichler, Walter

doi:10.3139/217.980071

Cited by 22 publications

(10 citation statements)

References 1 publication

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“…This radiation enters in the sensor through sapphire window where it is detected by IR diode. As shown by Obendrauf et al [20], due to the fact that plastics are partially penetrable for electromagnetic radiation in the near infrared range, polymer absorption coefficient can influence temperature measurement. Therefore, infrared temperature sensors have been placed directly in front of the pressure sensors with integrated thermocouples.…”

Section: Nozzle Designmentioning

confidence: 99%

Pressure and temperature behavior of thermoplastic polymer melts during high‐pressure expansion injection molding

Rogelj¹,

Krajnc

2008

Polymer Engineering & Sci

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The development of expansion injection molding as new technology for producing thin plastic parts has raised questions about polymer melt behavior in the process of rapid high pressure compression and expansion. To investigate those phenomena, the new in-line injection molding machine mounted measurement system has been developed. Measuring nozzle equipped with hydraulically driven closing bolts and contact fast response pressure and infrared temperature sensors enabled us to measure the compression and expansion of polymer melts at different starting conditions. Results presented for high impact polystyrene and polyamide show that polymer melt temperature rise is linearly dependent on compression pressure as well as it is dependent on compression speed. Comparable effect of temperature fall has been recorded during the polymer expansion, resulting in no noticeable loss of dissipation energy during this reversible process. Measurements have been compared with modified 2-domain Tait equation of state. Curve fitting analysis to manufacturer's material data show that measurements fit well with the model, even at very high compression speeds.

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Section: Nozzle Designmentioning

confidence: 99%

Pressure and temperature behavior of thermoplastic polymer melts during high‐pressure expansion injection molding

Rogelj¹,

Krajnc

2008

Polymer Engineering & Sci

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“…Infrared radiation penetrates the polymer melt and measure the temperature of melt at a certain depth. The penetration depth is not a constant quantity for a given polymer, but depends on the absorption of the polymer as well as the temperature distribution in the acceptance cone in front of the sapphire window [11,12]. This depth is an arguable question at present.…”

Section: B Infreared Sensorsmentioning

confidence: 99%

Temperature distribution measurement and control of extrusion process by tomography

Yang

Zhong

2008

2008 IEEE International Workshop on Imaging Systems and Techniques

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Polymer extrusion molding is an important process in the polymer manufacturing industry. It is crucial to measure and control the temperature of polymer melt. Although different techniques, such as thermocouple, infrared and ultrasonic, have been attempted to measure the temperature, there is no suitable means so far to measure the internal temperature in a cross section of a polymer extrusion process, and hence the process is operated by trail-and-error. Electrical capacitance tomography (ECT) is a non-intrusive and non-invasive technique to obtain permittivity distribution of a cross section. Because the permittivity is a function of temperature for a certain material, if the extrusion chamber is fully occupied by polymer, the temperature distribution can be derived from the permittivity distribution, which can be obtained by ECT. This paper reviews the existing methods to measure the temperature of polymer melt first. The approach and the key issues to measure the temperature distribution based on ECT will be discussed in detail.

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“…of the temperature profiles within and along the extrudate cross section, especially when the extrudate moves along the calibration/cooling system, is extremely difficult, requiring the use of thermocouples imbedded in the material, at different depths of the profile thickness, and moving with the profile (8). Profile surface temperatures between two consecutive calibrators are easier to monitor, but the quality of the measurements depends on the emissivity settings used in the noncontact infrared thermometers that are generally employed and also on the measuring depth, i.e., the thickness effectively reached by the radiation from the sensor (26). However, most of the temperature measurements reported concern pipes (1, 8,19,21,27) rather than profiles (20), and, even in this case, the data presented are insufficient for modeling purposes.…”

Section: Model Assessmentmentioning

confidence: 99%

Design of calibrators for extruded profiles. Part I: Modeling the thermal interchanges

Nóbrega

Carneiro

Covas

et al. 2004

Polymer Engineering & Sci

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The parameters influencing the calibration/cooling stage of profile extrusion are discussed, and a numerical finite-volume method code to model the heat transfer is described and validated. For this purpose, the numerical predictions are compared with the analytical solution of a simple problem, with results available in the literature and with those produced by a commercial software. The routines developed are then used to identify the main process parameters and boundary conditions and to estimate their relative importance. The investigation clearly shows the advantages of using several calibrators separated by annealing zones, relative to a single calibrator of the same total length, and the large impact of the contact resistance between extrudate and cooling unit while showing negligible impact of other boundary conditions. A decrease of the extrudate velocity is seen to be also an effective control parameter, but it decreases the production rates.

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Temperature Measuring in Plastics Processing with Infrared Radiation Thermometers

Cited by 22 publications

References 1 publication

Pressure and temperature behavior of thermoplastic polymer melts during high‐pressure expansion injection molding

Pressure and temperature behavior of thermoplastic polymer melts during high‐pressure expansion injection molding

Temperature distribution measurement and control of extrusion process by tomography

Design of calibrators for extruded profiles. Part I: Modeling the thermal interchanges

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