Multiple foam substrate to absorb impact energy together with an inflatable airbag is molded in two stages with an initial charge which sets to give a barrier surface for a second injection of foam to bond with the barrier surface

摘要

To form a multiple foam substrate, a mold (10) has two hollow molding zones. One foam material is injected into the first zone to fill it, and dwell for a sufficient time to form a barrier surface. The second foam material is injected into the other zone to fill it, and dwell for a sufficient time to bond at the barrier surface of the first charge. The molded multiple foam substrate is ejected from the mold. To mold a multiple foam substrate, the first foam material is injected while the mold is closed in one position, and the second material is injected while the mold is closed in a second position. The first foam charge is injected into the mold at a temperature of 70-90 deg F under a pressure of 90-3000 lbs/in2 for a time span of 1-15 secs., and is allowed to dwell for 2-3 mins. The second foam material is injected at a temperature of 70-90 deg F or 70-100 deg F under a pressure of 90-3000 lbs/in2 for a time span of 1-15 secs., and allowed to dwell for 2-3 mins. The molded substrate is removed from the mold, and allowed to harden at 70 deg F for 1-2 days. An inflatable airbag is positioned in the mold at the barrier surface of the first foam material, before the second foam charge is injected, within a notch formed in the barrier surface. A mounting is inserted into the mold before the first foam material is injected. The mold is heated to 120-150 deg F to form a surface skin on the molded substrate An Independent claim is included for a molded multiple foam substrate, using two foam materials where the second foam bonds to a barrier surface of the first molding. A further Independent claim is included for a mold with an upper part (14) angled into a right angle, with surfaces to carry mold sections. A lower part (12) carries the other mold section. The mold sections at the upper part are structured to give two closing positions for the mold assembly. Preferred Features: The upper mold part is brought to the lower part by a twist-lift motion. The upper mold part, together with an injection aperture, is structured so that the injection path leads to one hollow zone within the mold when it is closed in one position. When the mold is closed in the second position, a second injection aperture gives an injection path which leads to the other hollow molding zone.