The ideal process monitoring system for fast curing resins: easy to use at all environments and conditions

OptiMold data acquisition unit is based on advanced electronics allowing for the in-situ and real-time measurement of the ultra-high electrical resistance (up to 50 TOhm=5 1013 Ohm) of the cured thermoset and theroplastic resins even at production environment. This electrical resistance in combination with the measured temperature and real-time calculation can provide quantitative and qualitative indicators about the state of the resin such as resin aging, minimum viscosity, gelation and end-of-cure. Comparing to dielectric systems, OptiMold has been optimised for composites processing, so it is more powerful, faster and cheaper, more reliable and less vulnerable to carbon fibres and very robust at harsh environments. Last but not least it can be combined with a large range of innovative sensors which can be installed in the mould and in the feeding or the evacuation lines for RTM, LightRTM, SMC, BMC and other processes.

The new ultra-fast OptiMold can provide a resin arrival signal in less than 100ms and can measure successfully the fast-raising ultra-high electrical resistance of high-Tg of the newly developed fast-curing resins. Combining this system with our industry-proved durable in-mould sensor, automotive RTM
manufacturers have a powerful tool for real-time quality and process control. In the graph on the left, an indicative comparison of the electrical-resistance (and consequently of the Tg) built-up between the high-temp curing of a fast curing epoxy and PU resin is shown.

The OptiMold system can provide real-time information of a resin/composite state e.g. Tg, degree of cure, viscosity, mixing ratio, chemical aging. The OPTIMOLD system incorporates the OPTIMOLD data acquisition unit, a sensor and PC-based software. To monitor more than one location in a single mould, multiple units can be connected in parallel through a local wired or wireless network.

Besides process development, OptiMold can be used in production for online quality control, mixing ratio/quality check or identification of other deviations. For example, OptiMold can clearly distinguish when mixing ratio deviates as low as 3 % so corrective actions can be taken to maintain quality and speed. The industrial use of OptiMold in RTM applications has reduced cycle time up to 36% and increase production rate by 80%.

Responding to the high-demanding mass production of composite parts in the automotive sector OptiMold can be used for real-time quality control purposes providing a real-time control stamp of the produced part. The sensors can always be placed at areas that don't affect part quality even using them without any protection for carbon-fibre reinforced part production.

Furthermore, OptiMold output can be directly linked to existing press automation systems to open the press automatically based on the real-time Tg-prediction.

The OptiMold system has been used successfully in process monitoring of microwave and UV curing processes.

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