GB862930A - Method of adhesively bonding foldable board - Google Patents

Abstract

862,930. Seaming non-metallic sheet materials. BALJAK CORPORATION. Dec. 31, 1958 [Jan. 7, 1958], No. 42193/58. Class 42 (1). [Also in Group XVII] A method of adhering areas of two surfaces of board face-to-face comprises first applying to at least one of the surfaces an aqueous emulsion of a thermoplastic adhesive, then heating the applied adhesive while on the board to a temperature sufficient to coalesce the adhesive component and convert it from its divided emulsion state of low tackiness into a state of high tackiness and then pressing the two surfaces together whereby an instantaneous contact type bond is formed. In the embodiment shown, a sealing and closing machine 11 comprises a top rail 31 which engages the initially upright cover panel 21 of the box 14 and folds it into the position shown in Fig. 2. In this position flaps 24, 25 and 26 are in a position to be folded down and sealed. As the box is advanced by conveyer 12 the box first passes through a heating and dewaxing section 17 where a heating unit 32 removes the wax from the two surfaces to be sealed. After the box leaves section 17 the front flap 26 is flattened out and passed over an adhesive applicator in the form of a wheel 42 which applies a film of adhesive to the underside of flap 26. Guide rails ensure proper contact between the flap 26 and wheel 42. The adhesive is essentially an aqueous emulsion of the consistency of heavy orlan, the adhesive constituent being a polyvinyl acetate resin. The flap 26 is engaged by a rail 51 which brings the flap into contact with the wall panel 30 as the box 14 advances. The roller 52 presses the flap 26 against wall 30. At this stage the adhesive has a rather low degree of tackiness which is insufficient to hold the flap down after the box moves beyond roller 52 so that the flap 26 swings away from the wall panel 30 but some of the adhesive has been transferred to the panel 30. The box next passes into a heating- section where the adhesive is brought to a high degree of tackiness. The heat is preferably applied by quartz lamps. The box then passes into a closing section (Fig. 8) where the flap 26 is guided by rail 56 against the wall panel 30. A series of resilient pressure rollers 57 press the flap 26 into firm contact with the wall. The process is repeated for the side flaps 24 and 25.