WIT – Water injection technology

In 2001, Stieler Kunststoff Service GmbH contributed as consulting company to put a water injection article into series for the first time world-wide. It was a cooling water pipe for a French car.
Today, Stieler not only offers the equipment but also the adequate injection technology; this technology allows to completely remove the water from the mold.


In 2001, Stieler Kunststoff Service GmbH helped as a consulting company to put the first water injection project world-wide into series, a cooling water pipe. By now, the necessary water nozzles were further developed to be universally applied on a large scale.

On the 7th Kunststofftechnologietag (Day of plastics technologies), February 2003 in Goslar, a new water injection system was presented for the first time to 200 guests. In June 2003, the system was internationally applied with success on the NPE in Chicago.

The product: A handle bar of a motor saw (redesigned from an old GIT tool) with a PA6.6 GF30 that was specially developed by Barlog Plastics GmbH.

So far, the biggest problem was to demold dryly the product that was created via water injection. This was especially problematic when the future hollow was formed as a blind hole.

It is easily understandable that some vapor leaked from the hollow; with the boiling hot water, however, that dripped from some of the test elements, there was a great danger to get scalded.

Today, the sophisticated patented injector system uses compressed air flushing and an integrated recirculation of hot water and vapor. Thus, the plastic element can be demolded at normal pressure and without dripping. The illustration shows the polyamide handle bar with 30 % glass-fibrer reinforcement and its large and clear hollow. The internal surfaces are relatively smooth and even, without any undefined hollows or water blisters. The cycle time of less than 40 seconds is remarkable; however, most of the time is lost with draining the product.

wit_griff   Handle bar of a motor saw
made of polyamide with 30 % glass-fibrer reinforcement

The hydraulic control of the special injector technology is performed exclusively by the water injection device of Stieler Kunststoff Service GmbH.