Method for manufacturing interior door panels having concealed voids at the junction of integrally molded energy absorbers

摘要

An automotive interior door panel having a decorative covering displayed to the interior compartment of a vehicle and a rigid substrate having a backing surface. The backing surface includes a plurality of energy absorbers integrally molded thereon. The method utilizing the following steps. A low-pressure or high pressure injection mold operable between open and closed positions is moved to the open position. The mold has a covering receiving surface and an energy absorber producing surface. A flexible covering is positioned juxtaposed the covering receiving surface. The mold is moved to the closed position to create a space between the covering and the energy absorber producing surface. A molten plastic material is injected into the space to form the door substrate. The substrate has a nominal cross-sectional thickness between said energy absorbers. The energy absorber producing surface includes a plurality of recesses having a width 75% or more of the nominal substrate thickness producing thick-walled energy absorbers on the backing surface. The molten plastic material fuses to the covering to from an integral door panel. The plastic material is allowed to cool and shrink. The plastic shrinkage produces depressions in the substrate called sink marks overlying the intersection between the energy absorber and the substrate wall. The covering bridges the sink marks to conceal the depressions and produce an aesthetically pleasing surface.