Laminated Inkjet Article Adhesion via Intermediary Layer
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Solution Overview
Problem
Aqueous pigment-based inks used in high-speed digital inkjet printing on plastic substrates face issues with adhesion and drying due to the presence of humectants, leading to defects like mottle, coalescence, and intercolor bleeding, and result in poor lamination bond strength in flexible packaging materials.
Innovation Solution
A flexible inkjet printed article is developed with an aqueous-based ink-receptive layer containing water-soluble salts of multivalent metal cations, polyvinyl alcohol or polyvinyl amine, and silica particles, along with aqueous pigment-based inks having high water content and specific humectants, which improves adhesion and eliminates the need for a separate tie-layer, enhancing lamination bond strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If aqueous pigment-based inks with humectants are used for high-speed digital inkjet printing on plastic substrates, then printing speed and productivity are improved, but adhesion and drying performance deteriorate, causing defects like mottle, coalescence, and intercolor bleeding
Solution Approach 1:
A polymeric film or paper intermediate layer is introduced between the aqueous pigment-based ink and the water-impermeable plastic substrate. This intermediate layer acts as a mediator that accepts the aqueous ink during high-speed printing and subsequently transfers it to the plastic substrate, enabling both high printing speed and print quality without direct contact between incompatible materials
Solution Approach 2:
The system is segmented into distinct functional layers: the aqueous ink layer, the polymeric film/paper intermediate layer, and the plastic substrate. This segmentation allows each layer to be optimized independently - the intermediate layer can be designed with specific porosity and surface properties to handle aqueous ink while the plastic substrate maintains its water-impermeable characteristics
2Object-affected harmful factors
If aqueous pigment-based inks are used on water-impermeable substrates, then environmental safety is improved compared to solvent-based inks, but ink adhesion and substrate wetting deteriorate
Solution Approach 1:
The polymeric film or paper serves as an intermediary that is compatible with both aqueous inks and water-impermeable substrates. It provides a surface that can be effectively wetted by aqueous inks while maintaining strong adhesion to the plastic substrate, thereby enabling environmentally safe ink formulations to achieve reliable adhesion
Solution Approach 2:
The system forms a composite structure combining the polymeric film/paper with the plastic substrate. This composite material integrates the advantages of both components: the intermediate layer's affinity for aqueous inks and the substrate's water-impermeable and mechanically robust properties
3Ease of manufacture
If a separate tie-layer is added to improve ink adhesion on plastic substrates, then manufacturing complexity is reduced, but device complexity increases
Solution Approach 1:
The polymeric film or paper intermediate layer is designed to perform multiple functions simultaneously: it acts as a tie-layer for adhesion, provides a receptive surface for aqueous ink deposition, and facilitates drying by allowing vapor transmission. This multi-functionality reduces the need for separate dedicated layers for each function
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 improves the adhesion of aqueous-based ink-receptive layers to water-impermeable substrates, reduces defects in inkjet printing, and enhances lamination bond strength without sacrificing high-speed printing quality or productivity.
Implementation Method 1
an aqueous-based ink-receptive layer disposed thereon... improves the adhesion of aqueous-based ink-receptive layers to water-impermeable substrates
Implementation Method 2
aqueous-based ink-receptive layer... comprises: (a) one or more water-soluble salts of a multivalent metal cation... reduces defects in inkjet printing
Implementation Method 3
one or more of polyvinyl alcohol and polyvinyl amine, or a copolymer derived from a vinyl alcohol and a vinyl amine... enhances lamination bond strength
Implementation Method 4
a functional layer comprising an adhesive composition disposed on the inkjet-printed image; and a flexible polymeric film or paper adhered to the functional layer
Data Source
AI summary
A flexible inkjet printed article includes an ink receptive medium comprising a substrate and an aqueous-based ink-receptive layer. The aqueous-based ink-receptive layer has: (a) a water-soluble salt of a multivalent metal cation; (b) one or more of a polyvinyl alcohol and a polyvinyl amine (or a copolymer derived from a vinyl alcohol and a vinyl amine) at 0.5-30 weight %; and optionally, (c) a crosslinking agent or (d) silica particles. An inkjet-printed image is disposed on the ink-receptive layer, provided from one or more aqueous pigment-based inks, each having: a) one or more anionically-stabilized pigment colorants; b) one or more water-miscible humectants at 1-20 weight %, each of which has a carbon atom to oxygen atom ratio of at least 1.0:1.0 and only two hydroxy groups. A functional layer comprising an adhesive composition disposed on the inkjet-printed image; and a flexible polymeric film or paper adhered to the functional layer.