Method and apparatus for tacking a honeycomb core to a base sheet

In the method of making an insulated panel comprising tacking a base sheet to one face of an expanded core member, said expanded core member having plural open-ended cells and having coatings of adhesive, one provided on the ends of the cells on each face of said core member;

• filling the cells of said core member with thermal insulation;
• depositing a facing sheet on the other face of said core member in confronting relation with the coating of adhesive thereon;
• and curing the coatings of adhesive under pressure and by heating the coatings to the curing temperature of the adhesive, thereby to reliably bond said facing sheet and said base sheet to said core member;
• the improvement in the step of tacking said base sheet to said core member comprising:
• engaging said core member with said base sheet so that one said coating of adhesive contacts said base sheet, while moving said base sheet and said core member as a unit along a rectilinear path of travel;
• while engaging said base sheet with said core member,
• a. heating said base sheet to temperatures within a wetting temperature range of the adhesive, said wetting temperature range being below the curing temperature of said adhesive,
• b. maintaining said base sheet at temperatures within said wetting temperature range for a time interval sufficient to allow said one said coating of adhesive to be heated, to flow, and to form a fillet between said core member and said base sheet, said time interval being insufficient to allow heating of the other said coating of adhesive to temperatures within said wetting temperature range,
• c. quenching said base sheet to achieve a rapid cooling thereof to a temperature below said wetting temperature range of said one said coating of adhesive,
• d. conveying said base sheet and said core through a confined space, and
• e. introducing a cooling medium into said confined space to cool said base sheet and said one said coating of adhesive and the other said coating of adhesive to a discharge temperature, whereby a said base sheet is tacked to the ends of all of the cells and caps the cells on one face of said core member by a reliable temporary adhesive bond.