Plasma Coating Segmentation for Homogeneity Control
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Solution Overview
Problem
Plasma coating processes, particularly atmospheric pressure air plasma (APAP), face limitations in chemistry and homogeneity due to uncontrolled over-spray, which affects the uniformity and chemical composition of the coatings, leading to undesirable heterogeneous coatings.
Innovation Solution
The method involves plasma spraying a direct-spray component and an over-spray component onto a substrate surface, where the direct-spray and over-spray components have different cross-linked polymer chemistries, and can be adjusted in spray profile and content to control the chemistry, hydrophobicity, and homogeneity of the resulting coating, allowing for the formation of multi-layer coatings with controlled chemical compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If atmospheric pressure air plasma (APAP) coating process is used, then deposition rate is improved and cycle time is reduced, but coating homogeneity and chemical composition control deteriorate due to uncontrolled over-spray
Solution Approach 1:
The plasma spray output is segmented into distinct direct-spray and over-spray components using a plasma nozzle adaptor with selective shielding. The adaptor includes a direct-spray region that allows direct plasma-monomer contact with the substrate and over-spray regions that are selectively shielded during operation, enabling separate control of coating deposition and over-spray effects
Solution Approach 2:
Different regions of the plasma spray output are given different functions: the direct-spray region (central area) is optimized for controlled coating deposition with direct plasma contact, while the over-spray regions (peripheral areas) are selectively shielded to prevent uncontrolled monomer deposition. This local differentiation allows simultaneous achievement of high deposition rate and coating homogeneity
2Area of stationary object
If uncontrolled over-spray is present in plasma coating process, then coating coverage area is increased, but coating chemical composition control and layer uniformity deteriorate
Solution Approach 1:
The plasma nozzle adaptor is configured in advance with specific geometric features including a direct-spray region and shielded over-spray regions. The shielding structures are positioned to pre-determine which plasma spray components reach the substrate, ensuring controlled chemical composition before deposition occurs
Solution Approach 2:
The harmful uncontrolled over-spray components are extracted or removed from the plasma spray output by using the plasma nozzle adaptor to block peripheral plasma regions. Only the controlled direct-spray component with known chemical composition is allowed to deposit on the substrate, ensuring compositional stability
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 effectively controls the chemistry and homogeneity of plasma coatings, achieving cross-linked coatings with hexane stability comparable to direct-spray coatings, and allows for differential carbon atomic percentage in each layer, enhancing the versatility and control over coating properties.
Implementation Method 1
plasma spraying a direct-spray component onto a substrate surface, and plasma spraying an over-spray component onto the substrate surface
Implementation Method 2
The direct-spray and over-spray components may each have a different cross-linked polymer chemistry
Data Source
AI summary
A method of coating a substrate surface. The method includes plasma spraying a direct-spray component onto a substrate surface, and plasma spraying an over-spray component onto the substrate surface. The direct-spray and over-spray components form a plasma coating surface contacting at least a portion of the substrate surface.