In conventional hot runner systems, the plastic melt often follows a physically induced imbalance. The aim is always to generate processing-appropriate temperatures in the area of the injection point. However, to maintain the injection points at processing temperature, temperature zones build up in the rear part of the hot runner nozzles due to electric heating, which cannot directly heat the injection point, that are significantly above the target values. As a result, plastics degrade, form outgassing, and change the flow behavior. The outcome is fluctuations that can affect surface quality, dimensional accuracy, and process reliability. An air gap between the casing and the heated material pipe, as is common in conventional hot runner systems, can insulate the heat release to the mold but cannot prevent the unhindered entry into the melt—which inevitably leads to uneven temperature profiles.
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Uniformity is not a detail – it is the standard
In the global competition of plastic processing, it is no longer just speed or output that counts. The critical factor is quality in detail – reproducible, stable, and independent of external influences. This is where the MONOLITH® hot runner nozzle comes into play. "This development step was inevitable. If we want to offer our customers genuine process security in the global market environment of the future, we need to constructively eliminate physical weaknesses rather than compensate for them," says Martin Hallenberger, Head of Development and Design. MONOLITH® thus represents not only a technical advancement but also a change in perspective: moving away from reacting to process problems to constructively preventing them. In other words: Evenness is not a comfort feature – it is the new standard.
:format(avif):quality(75) "Cross-sectional thermal simulation of a cylindrical object, displaying a gradient from red to blue, indicating temperature variation.")
Conventional hot runner nozzles
:format(avif):quality(75) "Colorful thermal simulation of a turbine blade, showing a gradient from blue at the center to orange at the edges, indicating temperature variations.")
MONOLITH® Hot Runner Nozzles
In classical hot runner systems, the plastic melt often follows a physically induced imbalance. The goal is always to generate processing-appropriate temperatures in the area of the injection point. However, to maintain the injection points at processing temperature, temperature zones build up in the rear part of the hot runner nozzles due to electric heating, which, after all, cannot directly heat the injection point, and significantly exceed the target values. This causes plastics to degrade, form outgassing, and alter flow behavior. As a result, there are fluctuations that can affect surface quality, dimensional accuracy, and process reliability. The MONOLITH® nozzle, on the other hand, uses multiple strategically placed air gaps in the material tube, pressed between the melt and the heater, which ensures the heat is evenly distributed and only directed to the melt where necessary. This ensures a homogeneous temperature profile over the entire nozzle length and a stable basis for consistent component quality.
Technical facts: Air gap comparison
Feature | Conventional nozzle | MONOLITH® Nozzle |
Air gap | Single, larger gap between housing and material pipe | Several insulation columns between the melt and the heater, pressed into the material pipe |
Conduction | Uncontrolled overheating → uneven temperature profile | Adjusted heat conduction into the melt → homogeneous temperature profile |
Impact on melt | Different temperatures along the nozzle length → degradation, outgassing, defect patterns in the component | Uniform temperature → stable component quality, reduced process variations |
Process advantage | Higher thermal load, possible component defects | Less waste, secure processes, high repeatability |
Added value for the customer
The added value for the customer is clearly measurable:
less thermal stress on the material,
reduced fluctuations in the process and
a higher repeatability – independent of cycle times or material batches.
At the same time, efficiency increases because waste and process corrections are minimized.