Abstract
In design and simulation of injected parts, it is very important to understand correctly the relationship between pressure drop in a mold and flow length, since that is the clue in the design and manufacturing of a plastic piece.
Many of the components that are inside cars are aesthetic pieces, and they are textile coated. The upholstered pieces are injected onto a textile tissue introduced into the mold, and they are finished with an edging process. Simulation programs used to optimize the injection process are not able to simulate the injection over fabrics, and therefore, they cannot determine textile quality influence in the pressure drop.
The in-mold decoration (IMD) fabric is composed by three layers. The first one gives the aesthetics of the piece, the second intermediate layer is made of porous foam, and the third one is where the overmolded plastic is anchored. This article presents a methodology to determine the relationship between pressure drop and flow length, in order to optimize the IMD injection by means of simulation process. To design this methodology and characterize the IMD injection, a spiral mold with pressure sensors and three kind of textile with different protect liner quality and foam thickness are used.