Useful tips, infos

One of the conditions for precise and uniformly good quality production is that the temperature of the injection molding tool must always be within the range suitable for the given product. This goal is assisted by the tool tempering system, which heats or cools the circulating fluid in the tool according to demand.

It’s important to know that the tempering device can only heat the liquid (whether it’s water or oil) independently with its built-in heating elements. If cooling is necessary, the tempering liquid is cooled by the proper dosing of the connected chilled liquid (either mixed in or through a heat exchanger).

From now on, we will only deal with tempering systems that use water as the tempering fluid, since these are predominantly used by our partners in Hungary.

General rule is, that for every hundred kilograms of the tool being used, one kilowatt of tempering power is required. Of course, this should be specified during the design of the product and the tool.

One of the most common malfunctions is that the tempering water becomes limescaled, which results in a decrease in its efficiency. In the TCU’s tank, the sedimentary limescale on the heating elements reduces heating efficiency and leads to unnecessary energy consumption. The formation of limescale in the pipes results in a narrowing of the cross-section, which leads to a decrease in the amount of liquid transported over a unit of time. The consequence of all this is inadequate and increased energy-intensive tempering, which means a significant increase in costs.

Furthermore, like every tool, the TCU also requires and rewards regular care and maintenance. Our suggestion is that, based on the German model (where annual review is mandatory), our partners should also check and have their tempering equipment reviewed annually if possible. In addition, these reviews can be scheduled and can help prevent unexpected malfunctions. This way, production can continue smoothly for the satisfaction of both our partners and their clients.

What is often overlooked is that it is not only advisable to maintain the tempering machine but also the tools.Because limescale and other contaminants can cause cross-sectional narrowing and blockages in the cooling holes of the tool, thus again deteriorating both quality and productivity (cycle time increases), ultimately reducing profitability.

It is also often observed that no contamination filter is used in front of the tempering devices. We encountered “castrated” filters, from which the filter element had been removed for quick troubleshooting, then the lid was screwed back on, and the equipment was continued to be used without the filter. It is true that production could continue rapidly, however, as a result, contaminants could easily get into the tempering process, which later caused a much more significant production loss and repair costs.

For example that the silted water tank and the heating elements significantly reduce the tempering efficiency: The silted-up pump is just struggling, its motor is straining and yet it cannot efficiently perform its task. However, with a very small investment and some regular care, this can be prevented.