The optimal design of a filler die, coupling modeFRONTIER with Polyflow, is the challenge described in this paper. The objective of the analysis is the development of a balanced die profile for a controlled and smooth extrusion of the filler.
The rubber filler is a reinforcing part of the tyre close to the rim, with a nominal triangular shape. It is obtained as a sheet by extrusion through a profiled die, and then applied on the bead before tyre building process. The extruded sheet must be straight, in order to improve the bead filling process and be shaped on the nominal section inside tight tolerances.
Therefore, the optimal die profile must be designed in order to reduce the deformation of the filler profile due to the swell (expansion) of the rubber and, simultaneously, produce an even and balanced flow in order to avoid bending effects on the filler sheet.
To solve the latter requirement, the die inlet section is controlled by modeFRONTIER through nine geometrical parameters in the optimization loop, with the goal to reduce the flow un-uniformities and hence bending in the filler sheet. As the die is balanced at the end of this optimization loop, the best die outlet section is calculated through an inverse prediction problem, where the nominal filler profile is set as the input of a Polyflow internal optimization loop. |
