Abstract: A thermoplastic material melting unit including various grid and reservoir configurations designed, for example, to optimize flow rate, melt rate and residence time within a melting unit. A main embodiment includes a supply hopper connected with a liquid reservoir having a plurality of heat exchanging elements, such as fins extending upward from its bottom wall. A melting grid is generally disposed between the supply hopper and the reservoir and includes both upwardly and downwardly extending heated fins. The downwardly extending fins intermesh with the upwardly extending fins of the reservoir. Additional embodiments of melting grids and heat exchange devices for melting solid thermoplastic material include bare element configurations, angled fin configurations and slotted fin configurations.

Abstract: A fluid dispensing apparatus utilizing a through shaft metering gear pump. The metering gearhead includes an elongated drive shaft which receives multiple, self-contained gear pumps in a sliding manner. The gear pumps of the apparatus are connected to a fluid distribution manifold at a selected spacing with an inlet of each gear pump being connected to a central supply passage within the manifold and at least one outlet of each pump connected to a manifold outlet passage which may lead to suitable dispensing nozzles or guns. Each gear pump includes at least first and second gears with the drive gear being connected to the elongated drive shaft by way of a hollow shaft which provides both a sealing function and drive transfer function. The hollow shaft is keyed to the drive shaft to allow the pump body to be slid into the desired position.

Abstract: A fluid applicator having a multi-zone noncontacting die set for dispensing a selected plurality of thin flat fiberized adhesive streams as uniform rectangular strips of adhesive on a substrate. The die set uses shims to establish the fiberizing air slot, and the adhesive dispensing and fiberizing air shims have tapered tabs to provide improved coating edge control. The fiberizing air die also has simplified fiberizing air flow, and the die set includes a mechanism for clamping the die set together which is especially suited for a multi-zone die set. The fluid applicator includes a manifold heater with a simplified and improved air flow, and a universal adhesive manifold.

Abstract: A flue gas recirculation burner providing reduced No.sub.x emissions uses a cylindrical tangential mixer to separately receive combustion air and flue gas through axial inlets. The mixed air and gas pass through a vaned diffuser which continues the tangential flow pattern, and thereafter fuel is introduced tangentially and combustion occurs.

Abstract: A variable restrictor valve for use in an intermittent dispensing system having a recirculation loop. The restrictor valve establishes a more linear relationship between the amount of adjustment made thereto and the resulting pressure drop over the restrictor valve in the recirculation loop. A first embodiment of the restrictor valve changes the length of the flow path created by a helical groove to thereby adjust the flow resistance through the valve. A second embodiment uses a valve member in the form of a perforated cylindrical tube which is adjustable to present a varying number of perforations as the inlet to the tube and thereby allow adjustment of the flow resistance. A third embodiment utilizes a helical spring as a valve member in which adjustable spacing between the coils of the spring provides adjustability of the flow rate through the spring.

Abstract: An improved apparatus for spraying hot melt adhesive includes a gear pump for providing a metered flow of hot melt adhesive. When a valve member is in a first position, a predetermined rate of flow of hot melt adhesive is conducted from the gear pump to a nozzle. When the valve member is in the first position, the valve member blocks a flow of adhesive to a recirculation passage. When the valve member is in a second position, the valve member directs the flow of adhesive from the gear pump to the recirculation passage and blocks a flow of adhesive to the nozzle.

Abstract: A fluid applicator having a multi-zone noncontacting die set for dispensing a selected plurality of thin flat fiberized adhesive streams as uniform rectangular strips of adhesive on a substrate. The die set uses shims to establish the fiberizing air slot, and the adhesive dispensing and fiberizing air shims have tapered tabs to provide improved coating edge control. The fiberizing air die also has simplified fiberizing air flow, and the die set includes a mechanism for clamping the die set together which is especially suited for a multi-zone die set. The fluid applicator includes a manifold heater with a simplified and improved air flow, and a universal adhesive manifold.

Abstract: A method of monitoring and/or controlling the motion of a moving coating material dispensing pattern or fiber is provided with a monitor that senses a medium such as sound, light or other form of energy near the space between the dispensing device nozzle and a substrate, and a monitoring signal is generated. Information relating to the pattern motion is extracted, and an output signal is generated representative of characteristics of the motion of the pattern in the space. One or more transducers are used to extract the information, which is analyzed, preferably by comparison of a frequency spectrum of the signal with a spectrum of standard signal, to detect deviations in the system operation from desired criteria. Optionally, the output signal is used to control parameters of the system. In another embodiment, plural spaced transducers detect the phase or orientation of the moving pattern and remove background noise, by inverting, summing, multiplying, and otherwise combining the signals.

Abstract: A one-piece nozzle adapted for use within an adhesive dispenser includes a nozzle body formed with a throughbore having a discharge outlet within a nozzle tip portion which emits a bead of adhesive. A nozzle cap mounts the nozzle body to the adhesive dispenser such that an adhesive passageway within the dispenser communicates with the throughbore in the nozzle body and a plunger valve associated with the adhesive dispenser extends into the nozzle body in position to engage a seat formed at the nozzle tip. A number of air jet bores are drilled in the nozzle body, each communicating with an air passage formed between an outer surface of the nozzle body and an inner surface of the nozzle cap, which discharge jets of air into contact with the adhesive bead producing an elongated adhesive fiber deposited in a spiral pattern onto a substrate.

Abstract: An improved loop producing apparatus includes an adhesive gun and a nozzle member for emanating a bead of adhesive in a spiral pattern caused by the direction of air jets toward the adhesive bead as it emanates from the nozzle. A plenum chamber just upstream of the nozzle member is provided with diffusing or baffling means for diffusing the flow of air before it is introduced to the bores in the nozzle member. Overlapping loops of an adhesive bead are deposited onto a substrate in very consistent loop widths and with little loop width variation independently of the angular orientation of the nozzle member.

Abstract: A spray head attachment adapted for use with a flow metering device such as a metering gear head is effective to discharge a plurality of spiral spray patterns of hot melt adhesive, in elongated strands or fibers, onto the backing sheet of a hygienic article. The spray head attachment includes a manifold having adhesive passageways connected to outlets of the metering gear head, air passageways connected to a source of pressurized air and recirculation passageways connected to a source of hot melt adhesive. Outlets of the adhesive and air passageways, and inlets of the recirculation passageways, are formed on a discharge surface of the manifold in groups or arrays, so that nozzles mounted to the manifold are each connected to one array of adhesive, air and recirculation passageways.

Abstract: A thermoplastic melting apparatus comprises a tank pivotally mounted upon bearings within the interior of a housing having a top cover. An electrical or mechanical level indicator device is mounted exteriorly of the tank which is effective to sense pivotal movement of the tank as it is loaded with and/or emptied of thermoplastic material, and to produce a signal which indicates the quantity of thermoplastic material within the tank. The level indicator device is isolated from dynamic forces produced by drive linkages which operate pumps associated with the tank, by positioning the pivot axis of the bearings in the same plane as the force produced by the drive linkage. The lid of the tank is isolated from downward forces applied to the top cover of the housing to prevent the transmittal of forces to the level indicator devices from objects placed on the top cover of the housing or the like.

Abstract: A thermoplastic melting apparatus comprises a tank pivotally mounted upon bearings within the interior of a housing having a top cover. A load cell is mounted beneath the tank opposite the bearings which is effective to sense pivotal movement of the tank as it is loaded with and/or emptied of thermoplastic material, and to produce a signal which indicates the quantity of thermoplastic material within the tank. The load cell is isolated from dynamic forces produced by drive linkages which operate pumps associated with the tank, by positioning the pivot axis of the bearings in the same plane as the force produced by the drive linkage. The lid of the tank is isolated from the top cover of the housing to prevent the transmittal of forces to the tank from objects placed on the top cover of the housing or the like.