Spray Gun Needle for Post-Atomization Coating Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for applying coating compositions with multiple reactive components face challenges such as rapid viscosity increase and clogging due to premature reaction, leading to limited 'pot life' and increased VOC emissions when thinning agents are used to extend this period.
Innovation Solution
A spray gun design that separates the first and second components of the coating composition, allowing them to be atomized and mixed only at the nozzle, using a spray needle that slides between a spray and closed position to ensure precise delivery and prevent premature mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple reactive components are mixed together to form a pot mix prior to spraying, then the coating composition is ready for application, but the viscosity increases rapidly due to polymerization reaction leading to limited pot life
Solution Approach 1:
The coating composition is divided into multiple separate components (first component, second component, third component) that are stored and conveyed separately through independent channels to the nozzle. The components are not mixed until the moment of atomization at the nozzle, thereby preventing premature polymerization reactions and extending pot life while maintaining readiness for application.
2Duration of action of moving object
If a greater amount of thinning solvent is added to the pot mix to extend pot life, then the spraying time is extended, but VOC emissions increase and curing time increases
Solution Approach 1:
The invention changes the timing parameter of component mixing from 'prior to spraying' to 'at the moment of atomization'. By controlling when the components are combined (changing the temporal parameter), the system extends pot life without adding thinning solvents, thereby avoiding increased VOC emissions and extended curing times.
3Duration of action of moving object
If components are atomized and mixed after spray as described in U.S. Pat. No. 4,824,017, then pot life is extended, but separate pumps and injection means are required for each component increasing device complexity
Solution Approach 1:
The invention merges the conveyance of multiple components into a single spray gun body with integrated channels. Instead of using separate pumps and injection means for each component, the system uses one spray gun with multiple internal channels that converge at the nozzle, where all components are atomized and mixed simultaneously. This reduces device complexity while maintaining extended pot life.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach extends the 'pot life' of the coating composition, reduces VOC emissions, and maintains consistent viscosity of individual components during spraying, enabling efficient and effective application without clogging issues.
Implementation Method 1
a spray needle (56) comprising a first spray channel having a longitudinal first channel axis and a first channel opening, and a second spray channel having a longitudinal second channel axis and a second channel opening, said spray needle being housed within said tubular nozzle casing and being configured to slide between a spray position and a closed position
Implementation Method 2
producing atomized said first component and atomized said second component to form an atomized coating mixture by supplying a pressurized carrier to said carrier outlet through said carrier inlet
Data Source
AI summary
This invention is directed to a method for producing a coating layer of a coating composition comprising two or more components. The two or more components are mixed post atomization. This invention is also directed to a spray gun having a spray needle comprising two or more spray channels for producing such coating layer.