摘要:
A method and apparatus for forming and dispensing a coating material formulation or solution containing a liquid coating composition and a fluid diluent such as a supercritical fluid comprises a supply for the liquid coating composition, a supply for the fluid diluent, a mixer for combining the two components to form the coating material solution or formulation, and a control system for monitoring a parameter of the formulation which can be correlated to the fluid diluent content and/or liquid coating composition content of the formulation, and for monitoring the pressure of the formulation at selected locations within the system. The control system is effective to open or close the supply of fluid diluent and/or liquid coating composition in accordance with variations in the formulation parameter which is being sensed, and in response to pressure changes within the system, to maintain single or multiple phase coating material formulations, to account for changes in a parameter of the liquid coating composition and to ensure that the desired ratio of fluid diluent to liquid coating composition is maintained in the formulation which is supplied to coating dispensers for deposition onto a substrate.
摘要:
A method and apparatus for forming and dispensing a coating material formulation or solution containing a liquid coating composition and a fluid diluent such as a supercritical fluid comprises a supply for the liquid coating composition, a supply for the fluid diluent, a mixer for combining the two components to form the coating material solution or formulation, and a control system for monitoring a parameter of the formulation which can be correlated to the fluid diluent content and/or liquid coating composition content of the formulation, and for monitoring the pressure of the formulation at selected locations within the system. The control system is effective to open or close the supply of fluid diluent and/or liquid coating composition in accordance with variations in the formulation parameter which is being sensed, and in response to pressure changes within the system, to maintain single or multiple phase coating material formulations, to account for changes in a parameter of the liquid coating composition and to ensure that the desired ratio of fluid diluent to liquid coating composition is maintained in the formulation which is supplied to coating dispensers for deposition onto a substrate.
摘要:
A two-component thermosetting polymer system is formed and dispensed by adding a foaming agent to one of two components of the polymer system. A solution of the foaming agent in the first component is formed in a supply tank. The foaming agent and first component solution is then mixed with a second component at a dispensing head or nozzle. By adding the foaming agent to only one of the two components and, in particular, by forming a solution of the foaming agent in the first component one is able to very carefully control the foam density of the cured end product.
摘要:
Apparatus and methods for dispensing droplets of liquid or viscous material are disclosed. A valve is opened to dispense a stream of the heated liquid or viscous material through an elongated orifice of a nozzle. The stream of material being dispensed from the elongated orifice is broken into droplets by rapidly closing the valve. Furthermore, a method for varying the height of a droplet of liquid or viscous material is disclosed by which two or more droplets combine to form a droplet of a desired height. A method for applying a plurality of droplets of material onto a substrate so that the droplets flow together to form a uniform film of desired thickness and shape is also disclosed. A second embodiment of the invention relates to dispensing apparatus with a heater assembly removably attached to the dispenser housing. Another modification of the invention relates to a modified seat assembly wherein the valve has three positions with respect to the valve seat and a modified nozzle assembly wherein the nozzle is constructed of a thin walled tube.
摘要:
A method and apparatus for spraying adhesive compositions having a high solids content comprises a source of supercritical fluid diluent such as supercritical carbon dioxide, a source of virgin adhesive, an adhesive dispenser and a mixer communicating with each source of material and with the dispenser. The mixer includes a dynamic mixing element which agitates the viscous adhesive material allowing the supercritical carbon dioxide to be effectively dispersed into the adhesive, thus forming an adhesive composition with a high solids content having a relatively low viscosity suitable for spray application of the adhesive.
摘要:
Apparatus and methods for dispensing droplets of liquid or viscous material. The apparatus generally comprises a valve operated dispenser and a control for moving the valve member with respect to a valve seat in rapid succession. This rapidly accelerates liquid or viscous material in a stream from the dispenser outlet and immediately breaks the stream into a minute droplet. Various embodiments of the valve seat include both rigid valve seats and resilient valve seats. Resilient valve seats are especially useful for dispensing solder pastes as they can prevent material flaking, compacting and clogging conditions. Low friction polymer or plastic material for dispenser components such as the valve member and outlet structure can also prevent such problems.
摘要:
A method of atomizing a high solids viscous composition onto a substrate and foaming the composition comprising mixing a coating composition with a gas foaming agent under elevated pressure and temperature. The coating composition is airlessly atomized and projected onto a substrate. The gas remains dissolved in the coating after depositing on the substrate which causes the coating to foam after striking the substrate. The method provides a permanent foam coating composition with uniform cell distribution. The method is particularly suitable for foaming polymeric coatings such as plastisols and foods such as peanut butter or chocolate.
摘要:
A apparatus of atomizing a high solids viscous composition onto a substrate and foaming the composition comprising mixing a coating composition with a gas forming agent under elevated pressure and temperature. The coating composition is airlessly atomized and projected onto a substrate. The gas remains dissolved in the coating after depositing on the substrate which causes the coating to foam after striking the substrate. The apparatus provides a permanent foam coating composition with uniform cell distribution. The apparatus is particularly suitable for foaming polymeric coatings such as plastisols and foods such as peanut butter or chocolate.
摘要:
A method and apparatus for forming and dispensing a liquid coating material formulation or solution containing a nitrocellulose liquid coating composition and a supercritical fluid as a fluid diluent includes structure for combining the two components within a circuitous flow path or loop to form the coating material solution or formulation, while ensuring that the dissolved solids within the liquid coating composition do not precipitate and clog the supply of fluid diluent into the loop.
摘要:
A method and apparatus for forming and dispensing a coating material formulation containing a liquid coating composition and a supercritical fluid as a diluent comprises a closed vessel having a hollow interior; a system for supplying fluid diluent into the vessel interior and for transforming the fluid diluent into supercritical fluid within the vessel; and, a system for introducing liquid coating composition into the vessel interior in such a way that it is sufficiently exposed to the supercritical fluid to form a fluid diluent rich phase and a liquid coating composition or resin rich phase which is saturated with supercritical fluid up to or near its saturation point for the temperature and pressure conditions within the vessel. The resin rich phase has a higher density than the fluid diluent rich phase and therefore collects on the bottom of the vessel from where it is withdrawn and supplied to coating dispensers for deposition on a substrate. The coating material formulation which is not discharged from the dispensers is preferably recirculated back into the closed vessel in such a way that it is permitted to absorb sufficient supercritical fluid to return to the saturation point.