Ultrasonic Monitoring of Nozzle and Cavity during Injection Moulding

Abstract

Ultrasonic techniques are recognised as powerful sources of process information. Transducers are applied directly, are non-invasive, yet interrogate the entire melt cross-section, while data are available real-time. During injection moulding, two zones are considered: nozzle and cavity.

In the nozzle, ultrasonic velocity measurement provides temperature and pressure information. Mean temperatures not observed by other techniques are detected. Previous extrusion based experience is used to address issues of high temperature transducer operation. In the cavity, changes in reflection coefficient and ultrasonic velocity provide information on mould filling and part cooling. Various mould geometries are monitored using a number of ultrasonic transducers.

Keywords

ultrasound nozzle cavity temperature

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References

1. Thurston, RN ; (1964) Wave propagation in fluids and normal solids, Chapter 1 in Physical Acoustics, Principles and Methods, Vol. 1, Part A, Edited by WP Mason , Academic Press Inc., New York.

2. Brown, EC ; Olley, P ; Coates, PD ; (1997) Ultrasonic velocity dependence on polymer melt variables, SPE ANTEC, Toronto, Canada; Pp. 1042-1046.

3. Konno, M ; Cui, A ; Nishiwaki, N ; Hori, S ; (1993) Measurement of polymer melt temperature in injection molding machine by using ultrasonic techniques, SPE ANTEC, New Orleans, USA, Pp. 2798-2803.

4. Brown, EC ; Olley, P ; Collins, TLD ; Coates PD ; (1999) Ultrasonic investigation of process variation during single screw extrusion and injection moulding: real time detection of temperature profile and material degradation, SPE ANTEC, New York, USA; May 2-6.

5. Nishiwaki, N ; Cui, A ; Konno, M ; Hori, S ; (1994) Observation of solidification behaviour in mold by using ultrasonic technology, Proc. Polymer Processing Society, X Annual Meeting, Paper No. 6-1-7, Pp. 182-183.

6. Wang, H ; Cao, B ; Jen, K ; Nguyen, KT ; Viens, M ; (1997) On-line ultrasonic monitoring of the injection molding process, Polymer Engineering and Science, Vol. 37, No. 2, (February), Pp. 363-376.

7. Jiang, M ; Thomas, CL ; Peterson, R ; Bur, AJ ; (1997) New ultrasonic solidification sensing techniques for injection molding, MD-Vol. 79, CAE and Intelligent Processing of Polymeric Materials, ASME, Pp. 213-222.