The WITTMANN Group has upgraded the WiAssist app by adding a new plasticizing module, which calculates the material’s dwell time inside the plasticizing unit, thus simplifying the selection of the screw size.

By calculating the dwell time, the WiAssist app from WITTMANN simplifies plasticizing process.

WiAssist supports injection molders in selecting and setting up their injection molding machines. As an app, the digital assistant is always available at hand via smartphone and saves users from laborious calculations.

Screw within optimal range

An over- or undersized screw may impair both processing efficiency and parts quality.

The essential feature is the material database contained in the app. After the material, shot weight and cycle time have been entered, the app calculates in a few seconds the relevant process parameters, such as cooling time, internal mold pressure, injection pressure, screw speed and – as a new feature – also the melt’s dwell time inside the plasticizing unit.

This additional function makes it possible to select the optimally suited injection molding machine for a given mold in less than one minute – for instance where injection molding machines with different screw sizes are available in a large machine fleet.

The new screw module can be used for 3-zone screws from the WITTMANN Group. Here, the app calculates the optimal dwell time and gives recommendations for the appropriate screw diameter and metering stroke as well.

A clear graphic display shows which values are within the optimal range, which ones are only partly suitable and which ones are not at all suitable.

Careful selection of the plasticizing unit is vital, because the screw has an immediate effect on parts quality and processing efficiency. If the screw diameter is too small, this shortens the dwell time, and the material is melted insufficiently. But if the screw is dimensioned too large, this lengthens the dwell time, with the possible result of thermal damage to the material and faulty parts as a consequence.

Troubleshooting included

The WiAssist app offers a total of five functions:

• Querying material properties

• Assistance with the selection and setting of injection molding machines

• Calculation of process parameters

• Troubleshooting

• Direct contact with WITTMANN

The troubleshooting module includes an extensive database with frequent injection molding faults, possible causes and problem-solving suggestions.