Abstract: A thermoplastic material melting and dispensing apparatus includes a hopper, a melting grid, and a lid assembly which vents the interior of the hopper in an over pressure situation. Specifically, the lid assembly may be mounted with a spring-loaded hinge mechanism and may include a spring-loaded latch mechanism which each allow the lid to move upwardly away from a gas seal in the event that the gas pressure within the hopper exceeds a predetermined amount. The apparatus further includes a gas purging system which constantly circulates a gas, such as nitrogen, within the hopper interior. This gas purging system may include a solenoid valve which opens to allow exhaustion of pressurized gas from the hopper interior and the introduction of gas from a pressurized supply. A melting grid is provided which includes an surface with grooves communicating with a central outlet.

Abstract: A device for retarding drool from a multi nozzle manifold having a plurality of outlet passageways in fluid communication with a single feed passageway. A drool-retarding member selectively segregates the outlet passageways with respect to fluid communication among the outlet passageways, preventing flow from one outlet passageway into a lower outlet passageway during adhesive cutoff periods. The drool-retarding member is a reciprocating member having an inoperative position in which a plurality of inlet ports to the outlet passageways are sealed, and having a fluid-apply position in which the inlet ports are free to allow fluid communication among the outlet passageways and the feed passageway. In a passive embodiment, the drool-retarding member is a valve that is spring biased to cover the inlet ports. Pressurized adhesive overcomes the bias of the spring when an upstream flow-regulating mechanism is controlled to discontinue adhesive flow.

Abstract: A modular adhesive applicator assembly in which electrical, thermal and fluid communication between a main block and individual modules occur at one face of the main block and in which a separate flow loop within each module is provided to prevent adhesive degradation within the module. Each module has an inlet port in fluid communication with an opening in the main block. The inlet port is located at an intermediate region of a solenoid armature used to control flow from the inlet port to an outlet port. A high-volume adhesive flow path extends forwardly along the solenoid armature directly to the outlet port. A low-volume adhesive loop extends rearwardly along grooves within the exterior of the solenoid armature and then forwardly within a central bore of the solenoid armature. A radial bore to the central bore provides fluid communication to the high-volume adhesive flow path.

Abstract: A method of forming a sift-proof seal for closure of a box having a plurality of folded flaps, the seal being formed by an adhesive strip pattern. The flaps are moved linearly toward a plurality of nozzles which extrude adhesive in a pattern of closely spaced adhesive strips. A flap having such an adhesive pattern is brought into contact with a second flap to compress the pattern of adhesive therebetween. The spacing between adjacent strips of adhesive is such that the folding of the flap causes merging of the adhesive to form a continuous strip of adhesive, thereby forming a box closure. The adhesive pattern is limited to a first outside edge of the first flap, with each remaining outside edges receiving a sift-proof continuous line of adhesive.

Abstract: A method for applying adhesive to join two surfaces. A nozzle has a body member and a conical tip extending from an outlet face of the body member. A first pair of gas passageways is disposed on a side of the conical tip opposite a second pair of gas passageways. Each of the four gas passageways has a dispensing orifice at the outlet face of the nozzle body. The pairs of passageways are inwardly directed to project streams of gas, preferably air, parallel opposed sides of the conical tip. Thus, the streams of air converge at a distance from the outlet face beyond the apex of the conical tip. These streams of air cradle a stream of material issuing from the apex of the conical tip and cause an oscillatory asymmetric figure eight deposition of material. The deposition on a first surface has a resonant frequency and has smooth, controlled radius turns at its edges. A second surface is then brought into contact with the first surface while the adhesive is still in a fluid state.

Abstract: An electromagnetic valving assembly for viscous fluid material having a solenoid body with an axial flow passageway and an outlet port. A ferromagnetic pole piece is attached at an upstream end of the solenoid body and is in fluid communication with a source of viscous material, such as hot-melt adhesive. An armature is reciprocatingly mounted within the flow passageway and a spring biases the armature in a closed position which blocks the outlet port. A solenoid coil is disposed to cause magnetization of the pole piece during conduction of current through the solenoid coil. The magnetization provides an attractive force between the pole piece and the armature to draw the armature into contact with the downstream surface of the pole piece. The upstream end geometry of the armature includes a center bore for passage of the viscous material and includes a recessed inner region and raised C-shaped edges. Contact between the pole piece and the armature is limited to the C-shaped raised edges.

Abstract: A nozzle and a method for applying adhesive to join two surfaces. The nozzle has a body member and a conical tip extending from an outlet face of the body member. A first pair of gas passageways is disposed on a side of the conical tip opposite a second pair of gas passageways. Each of the four gas passageways has a dispensing orifice at the outlet face of the nozzle body. The pairs of passageways are inwardly directed to project streams of gas, preferably air, parallel opposed sides of the conical tip. Thus, the streams of air converge at a distance from the outlet face beyond the apex of the conical tip. These streams of air cradle a stream of material issuing from the apex of the conical tip and cause an oscillatory zig-zag deposition of material. The deposition on a first surface has a resonant frequency and has smooth, controlled radius turns at its edges. A second surface is then brought into contact with the first surface while the adhesive is still in a fluid state.

Abstract: A nozzle for applying a quasi-random splatter pattern of viscous fluid material. The nozzle includes an axially inward gas flow path and an axially outward material flow path. The material flow paths are partially defined by an array of material flow passageways that are yieldingly obstructed by a valve member. The valve member has a center bore to permit passage of a stream of gas. Pressurization of the viscous fluid material causes the material to exceed the threshold pressure for axial movement of the valve member. The viscous fluid material will thereafter flow to an outlet orifice having a configuration which is at least closely similar to the array of material flow passageways. Material at the outlet orifice is impinged by the stream of gas through the nozzle for projection to a surface.

Abstract: A nozzle assembly for use with a hot-melt dispensing head having a manifold with a lengthwise passageway opening into plural, spaced-apart nozzle inserts for dispensing hot melt. The nozzles themselves are aimable over a wide range of angles and are replaceable. In one configuration the nozzle assembly has a T shape with the nozzles on a side of the T top distal to the dispenser head. In another configuration, the nozzle assembly has a Y shape with the nozzles on a side of the Y top facing the dispenser head. The two configurations may be spaced opposite each other to form a box sealing station.

Abstract: A hot-melt tank having side walls and a bottom wall with a melt unit mounted on the bottom wall in the lower region of the tank, a melt zone. The melt unit includes a base mounted in the lower region and upwardly extending, spaced apart, parallel fins having a sloping upper end. The base does not block a material outflow port in the bottom wall of the tank, but is oriented so that the lowest portion of the sloping upper end of the fins is distal to the outflow port. A shelf, parallel to the bottom wall is positioned over the outflow port parallel to the base, intercepting the fins and secured thereto for blocking direct material inflow from the top of the tank into the outflow port. Rather, material flow is equalized in the lower region of the tank, being drawn to the outflow port from both short and long paths.

Abstract: A nozzle assembly for a hot-melt dispensing head having a heat transfer block from the head to a manifold. The manifold includes a passageway for hot-melt with plural, spaced apart nozzle inserts for dispensing hot-melt. In one configuration the nozzle assembly has a T-shape with the nozzle inserts on a side of the T-top distal to the dispenser head. In another configuration, the nozzle assembly has a Y-shape with the nozzle inserts on a side of the Y-top facing the dispenser head. The two configurations may be spaced opposite each other to form a box sealing station.