How a mixing nozzle improved quality of inhaler housings

A manufacturer of an inhaler housings from Asia was struggling with colour streaks in their injection moulded components. The result was an above-average reject rate and causing high costs for quality control since each housing had to be checked for possible defects.

Increasing the back pressure, a common solution for this type of defect, brought only a slight improvement while resulting in longer cycle times and, as a consequence, lower productivity. After installing a Promix Solutions mixing nozzle however, the colour streaks were eliminated, with the cycle times changed back to normal settings and even shortened by a further four seconds. This resulted in an overall productivity increase which the customer puts at 12.5%.

“The investment costs for the Promix mixing nozzle were paid back within 2 months, thanks to the quality improvements and cost savings achieved,” says the plant manager. “Not only that, the higher homogenising capacity in the mixing nozzle allowed the back pressure to be reduced from 280 bar to 80 bar, which corresponds to a reduction of around 70%. As a result, it was possible to significantly reduce wear on the gearbox and thus maintenance costs.”

“If you look closely, you will find machines in a lot of injection moulding companies that are not running optimally and injection moulded parts that are causing problems,” explains Rolf Heusser, CEO of Promix Solutions. “You can think of increased cycle times, part warpage, colour streaks, high masterbatch consumption or weak points in flow seams, the challenges are adamant. But often these problems can be solved simply and cost-effectively. Our mixing nozzles can be delivered ready for connection within a few weeks and in many cases help to eliminate quality problems, increase productivity, and reduce the CO2 footprint.”