STRUCTURAL BONDING WITH ENCAPSULATED FOAMING ADHESIVE

A improved panel structure wherein at least one face of the panel is perforated with small holes and where it is desirable to minimize the number of holes that get filled in with adhesive. For example, an improved noise reducing acoustic panel (30) (FIG. 3) constructed of a nonperforated inner skin (14), a perforated outer skin (16) having small holes (18), two sections (12, 12a) of honeycomb core material which are bonded or spliced together by a partially or fully encapsulated foaming adhesive (32e) which has been foamed and expanded, thereby forcing a supported film adhesive (34c) against the walls (24, 24a) of the honeycomb cells in the area of the gap (22) whereby the supported film adhesive (34c) bonds to the walls (24, 24a) of the honeycomb cells in the area of the gap (22). The nonperforated inner skin (14) has been adhesively bonded by a film adhesive to the honeycomb core sections (12, 12a). The perforated outer skin (16) has been adhesively bonded by an unsupported film adhesive to the honeycomb core sections (12, 12a). Encapsulated foaming adhesive (32e) has no horizontal bleed out and it fills a minimum number of the small holes (36, 36a) in the perforated outer skin (16), thereby maximizing the desired noise reducing capability of the acoustic panel (30). As compared to the prior art acoustic panel (10) (FIG. 1), the acoustic panel (30) (FIG. 3) of the invention has a smaller number of filled holes (36, 36a) and a smaller splice width. It also has a neater appearance and a more uniform pattern of filled holes (36, 36a).