WATER INJECTION TECHNOLOGY
NOW THERE'S A GOOD IDEA...When it comes to mould technology innovation, Moldetipo Group is recognized by its peers and clients as miracle workers.
WIT is a revolutionary technology that stands for cost reduction and performance improvement in production cycles.
In 2015, Moldetipo was awarded in Germany as “Best mold maker” in the 16th Automotive Awards. Competing with companies from all over the world, Moldetipo’s expertise was confirmed in the Power Train section, thanks to a project for BMW. The innovative tool was based on water injection technology, that Moldetipo has been developing for several years. The BMW project (through Batz) is a clutch pedal made entirely in plastic.
Water-assisted injection molding is the newest way to mold hollow or partly hollow parts. It’s basically similar to gas-assist molding as a means to core out thick sections. And water-injection technology (WIT) comes with a big advantage: direct cooling inside the part. The thermal conductivity of water is 40 times greater than that of gas, and water’s heat capacity is four times greater than gas. With the cooling capability of WIT, cooling cycle times can be reduced to only 25% of that of gas.
But the potential for faster cycles is only part of the story. WIT can yield thinner, more uniform part walls, which adds to material savings. WIT’s ability to produce a smooth internal part surface, which is much more difficult with gas assist, makes injection molding much more competitive with blow molding. Some sources also believe WIT can produce larger void spaces and longer hollow sections in parts than gas can. The considerably shorter cycle times and the non-incurred fluid costs by using water are the main focus. For large quantities this can lead to a reduction of the investment costs by up to 50% (halving of the production lines due to the increase in efficiency of each line).
There is a tendency to use gas, when shrinkage has to be compensated, melt accumulations are not avoidable, channel cross sections are too small as well as the water cannot be removed from the component or when the size of the injector is decisive. Water, is automatically used when the crosscuts and the channel length get too big in dependence of the material for the gas injection technology and when a smooth and closed surface is demanded e.g. in sanitary areas. The residual wall thickness generally plays a central role besides the low warpage.
