Autonomous and electric vehicles
HMI Dashboard

Customer Expectation

The main challenge for HRSflow was to manage the back injection of Polycarbonate (PC) on capacitive IMD film in a one-step injection process, the so called FIM – Film insert molding process. The purpose of the decorative film was to make lighting effects visible when backlighted.

Customer requests:

  • Validate injection solution with direct gating avoiding typical aesthetical defects of the application
  • Validate FLEXflow Evo solution to reduce the residual stresses on the interactive screen area 
     

 

Our Solution

HRSflow supported preliminary part design, with special attention to thickness & polymer definition, by testing different solutions by injection simulation.

The capacitive film is back-injected with (PC) Polycarbonate to appear like clear glass in the touch area of the control panel. Thanks to FLEXflow Evo, the sensitive film doesn’t encounter any stresses that normally arise from the injection process. An uncontrolled injection of one-step opening of the needle, as with conventional hot runner systems, would damage the film. Moreover, in order to inject both foils at the same time, it was necessary to keep the internal pressure in the PC glass area low. This is possible with FLEXflow Evo because the injection profile can be set on each individual nozzle and thus a pressure profile can be set for this area. 

The final solution achieved considers a part modification on IML foil, optimization of cold runner and part thickness, definition of best drop locations and definition of process boundary conditions to ensure the best results on the part
 

HRSflow system
  • 5 drops Ha series, FLEXflow Evo system, single level.
  • Cylindrical gate style, Ø2.5 mm
General information
Application field: Autonomous vehicles
Part name: Interactive dashboard
Part size: 910 x 33 mm
Nominal weight: 287 gr
Nominal  thickness: 2.3 mm 
Material: PC
Technology: FLEXflow Evo
Features