Coated Substrate Feathering Reduction Trivalent Chromium Pretreatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coatings used in food and beverage packaging often lack multiple desirable properties such as high-speed application, good adhesion, and safety for food contact, with hexavalent chromium-free substrates experiencing undesirable feathering issues that pose safety risks due to potential ingestion of coating materials.
Innovation Solution
A coating composition comprising a polymeric binder and a feathering reducing agent with a carboxylic acid reactive functional group, applied over a pretreatment layer containing a trivalent chromium compound, which reduces feathering and enhances adhesion and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If hexavalent chromium-free substrates (trivalent chromium) are used, then safety for food contact is improved, but feathering occurs causing coating integrity to deteriorate
Solution Approach 1:
A pretreatment layer comprising chromium hydroxide or chromium oxyhydroxide is applied as an intermediary between the trivalent chromium substrate and the coating composition. This intermediary layer modifies the substrate surface properties to prevent feathering while maintaining the safety benefits of chromium-free substrates, enabling both coating integrity and food contact safety
Solution Approach 2:
The patent changes the chemical and physical parameters of the substrate surface through the pretreatment layer, modifying surface energy, roughness, and reactivity to eliminate feathering. The coating composition parameters are also adjusted with specific resins and additives to optimize performance on the pretreated surface
2Productivity
If conventional coatings are applied to achieve high-speed application, then productivity is improved, but adhesion to the substrate deteriorates
Solution Approach 1:
The pretreatment layer is applied in advance to prepare the substrate surface for optimal coating adhesion. This preliminary action creates a surface that promotes strong bonding, allowing conventional high-speed coating application methods to achieve both productivity and adhesion requirements
3Manufacturing precision
If feathering is reduced to improve coating integrity, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The pretreatment layer serves as a simple intermediary that addresses the feathering problem without requiring complex equipment modifications. This approach achieves manufacturing precision through material selection rather than process complexity
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
The solution effectively reduces feathering by at least 20% and improves adhesion and safety, ensuring the coating remains intact and safe for use in food packaging applications.
Implementation Method 1
a feathering reducing agent comprising a carboxylic acid reactive functional group
Implementation Method 2
contacting a coating composition with a substrate that comprises a pre-treatment layer
Data Source
AI summary
A coated substrate comprising a coating extending over at least a part of the substrate. The coating is obtainable from a coating composition comprising (a) a polymeric binder; and (b) a feathering reducing agent comprising a carboxylic acid reactive functional group. The coated portion of the substrate comprises a pretreatment layer. The pretreatment layer is obtainable from a pretreatment composition that comprises a trivalent chromium compound. The invention extends to a method of coating a pre-treated substrate and a coated package, such as a metal can.