Spray Applicator Solvent-Enriched Purging for Residue Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plural component sprayers face issues with clogging and curing of materials due to incomplete purging, particularly when using moisture-sensitive components like isocyanate, which can form crystals and cause damage to seals and pathways.
Innovation Solution
A spray applicator design that includes separate purge air flows for each component, with solvent injection through one flow to prevent curing, using a trigger mechanism to switch between spray and purge modes, ensuring thorough purging and preventing material residue buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If purge air is used to clear material from the mix chamber, then material residue is removed, but moisture-sensitive components can still cure and cause clogging
Solution Approach 1:
A solvent is introduced as an intermediary substance into the purge air stream. The solvent acts as a mediator that prevents material curing while the purge air continues to clear residue. The solvent is injected into the purge air pathway where it mixes with the purge air and contacts residual material, preventing curing without requiring direct contact between pure purge air and cured material
Solution Approach 2:
The chemical composition parameter of the purge medium is changed by adding solvent to the purge air. This transforms the purge medium from simple air to a solvent-enriched gas mixture that has both the clearing capability of air and the curing-prevention properties of the solvent. The solvent concentration is controlled to be sufficient for prevention but not excessive
2Reliability
If solvent is added to purge air, then material curing is prevented, but system complexity increases
Solution Approach 1:
The solvent injection function is merged with the existing purge air delivery system. The solvent injector is integrated into the purge air pathway, allowing the solvent to be introduced and mixed with the purge air without requiring completely separate delivery infrastructure. This combines two functions (purge air delivery and solvent delivery) into a unified system
Solution Approach 2:
The system uses its own purge air flow to deliver the solvent to the mix chamber. The purge air that would otherwise just clear residue now also serves as the carrier gas for the solvent, making the purge air perform a dual function. This self-service approach eliminates the need for separate solvent delivery infrastructure
3Reliability
If separate purge air flows are used for each component, then purging thoroughness is improved, but device complexity increases
Solution Approach 1:
The purge system is segmented into separate pathways for different base components, with each pathway receiving purge air and solvent independently. This segmentation allows each component to be purged separately, ensuring thorough removal of residue from each component pathway and the mix chamber without cross-contamination
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
Effectively prevents clogging and curing of plural component materials by using solvent-enriched purge air, maintaining system integrity and extending the applicator's operational life.
Implementation Method 1
Solvent is injected into only one of the first and second purge air flows to be carried to mix chamber by that portion of the purge air
Implementation Method 2
The solvent assists in clearing residue from the mix chamber
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A spray applicator is operable in a spray state, during which the applicator emits a plural component material formed within a mix chamber of the spray application, and a purge state, during which the spray applicator emits compressed air from the mix chamber. First and second portions of the purge air are provided to the mix chamber through separate flowpaths and combine within the mix chamber. Only one of the portions of purge air is routed through a dosing chamber to entrain solvent and carry the solvent to the mix chamber. The solvent assists in clearing residue from the mix chamber.