Patent ID: 9061648
Filing Date: 2015-06-23
Classification: B29C,B29L,B60R,Y10T

Abstract:
1. A method of forming a tear line of an airbag door using an in-mold blade, comprising the steps of: a) confirming a time point when resin flow in an airbag door tear line portion is completed in an injection mold; b) after the confirming the time point, transferring a resin arrival signal to a blade operation portion for operating the in-mold blade; c) moving the in-mold blade forward at an in-mold blade forward time point that substantially corresponds to a receiving time of the resin arrival signal; d) completing the forward movement of the in-mold blade for interrupting the resin flow by the in-mold blade and starting dwelling after the completing the forward movement of the in-mold blade; e) moving the in-mold blade backward before the dwelling is completed; f) completing the backward movement of the in-mold blade after the dwelling is completed and cooling starts; wherein in the step e), the backward movement of the in-mold blade begins before the dwelling is completed, and the in-mold blade moves backward at a time point when a tear line residual depth is not reduced due to adhesion of the resin inside the tear line; and wherein a predetermined time period between an initial backward movement of the in-mold blade and an end of the dwelling is one to three seconds, and wherein speed of the backward movement of the in-mold blade is kept constant through the duration of the backward movement.