Thermal Sublimation Paper Coating for Fast Drying and High Transfer Yield
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Solution Overview
Problem
Existing thermal sublimation papers face challenges with adhesion to textiles, rapid ink drying, and mottling during printing, particularly with inkjet inks, which affect the transfer yield and quality of the printed image on textiles.
Innovation Solution
A thermal sublimation paper with a hydrophilic thermal transfer layer containing thermoplastic particles of specific size and melting point ranges, applied to a porous base paper, enhances adhesion and ink drying while reducing mottling by maintaining an open paper structure and optimal porosity, allowing for better inkjet ink absorption and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermal sublimation paper uses a barrier layer with low permeability to prevent color running, then color stability is improved, but ink drying speed decreases
Solution Approach 1:
The patent employs a porous barrier layer made of carboxymethyl cellulose with controlled porosity (100-400 ml/min according to ISO 5636-3). The porous structure allows water in the ink to evaporate through the layer, enabling rapid ink drying, while the controlled pore size and hydrophilic properties prevent dispersed dye particles from penetrating through, thus preventing color running. This resolves the contradiction by allowing both fast drying and color stability through optimized porous structure.
Solution Approach 2:
The patent optimizes specific parameters of the barrier layer including porosity (100-400 ml/min), degree of substitution of carboxymethyl cellulose (0.2-0.3), and layer composition to achieve the desired balance. By precisely controlling these parameters, the barrier layer provides sufficient permeability for water evaporation while maintaining adequate retention of dye particles, thus resolving the contradiction between drying speed and color stability.
2Reliability
If a thermal sublimation paper uses a barrier layer to prevent color running, then color stability is improved, but adhesion to textile decreases
Solution Approach 1:
The porous barrier layer with controlled porosity (100-400 ml/min) allows water to pass through while retaining dye particles on the paper surface. This prevents color running during storage and handling, and the hydrophilic nature of carboxymethyl cellulose ensures good adhesion to textile fibers during the thermal sublimation process, resolving the contradiction between color stability and adhesion.
Solution Approach 2:
The barrier layer is composed of carboxymethyl cellulose combined with specific fillers and binders to create a composite material that simultaneously provides color retention properties and adhesion promotion. The composite structure allows the layer to function as both a barrier to color running and an adhesive interface for textile bonding.
3Speed
If a thermal sublimation paper uses high porosity for rapid ink drying, then ink drying speed is improved, but color running increases
Solution Approach 1:
The patent uses a porous barrier layer with specifically controlled porosity (100-400 ml/min according to ISO 5636-3). This controlled porosity allows water in the ink to evaporate rapidly through the layer, achieving fast ink drying, while the pore size and hydrophilic properties of carboxymethyl cellulose prevent dispersed dye particles from penetrating through, thus preventing color running. The key is the optimized balance in porosity parameters.
4Reliability
If a thermal sublimation paper uses a dense barrier layer to prevent color running, then color stability is improved, but transfer yield decreases
Solution Approach 1:
The patent employs a porous barrier layer with controlled porosity (100-400 ml/min) that allows water to pass through during ink drying but retains dye particles on the surface. This prevents color running while maintaining high transfer yield during thermal sublimation printing, as the dye particles remain accessible for transfer to the textile substrate.
Solution Approach 2:
The patent optimizes the porosity parameter to a specific range (100-400 ml/min) that balances color retention and transfer efficiency. This parameter optimization ensures that the barrier layer is sufficiently porous to allow water evaporation and maintain dye particle accessibility for transfer, while still providing adequate barrier function to prevent color running.
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 achieves improved adhesion, rapid ink drying, and significantly reduced mottling, resulting in a high transfer yield and superior print quality on textiles, particularly with polymeric fibers like polyester.
Implementation Method 1
Sublimation refers to the direct transition of the dyes from the solid to the gaseous state of matter, without the otherwise customary intermediate liquid-state step
Implementation Method 2
the dyes, in the range from about 170 to 230° C. and at sufficient rate, sublime and diffuse, for example, into the fibres of the textile and thus adhere effectively therein
Implementation Method 3
the barrier layer is said to have a composition such that the water in the aqueous dispersion of the sublimable dye particles of the inkjet ink is absorbed relatively quickly
Data Source
AI summary
The invention relates to a thermal sublimation paper which can be printed with inks containing a sublimatable dye, in particular ink-jet inks, in which paper a hydrophilic thermal transfer layer to be printed is formed on a porous base paper. Thermoplastic particles with an average particle size of between 0.3 and 5 μm and a melting point of between 35° C. and 190° C. are present in the thermal transfer layer. This thermal sublimation paper can be advantageously produced as follows: an aqueous coating slip is applied to a porous base paper having a Cobb value of between 55 and 150 g/m2, in particular between 70 and 150 g/m2, in a paper-making or coating machine, online or offline, said aqueous coating slip containing thermoplastic particles and constituents suitable for forming a hydrophilic thermal transfer layer, and a drying step is subsequently carried out in order to obtain the thermal sublimation paper. The thermal sublimation paper can be used advantageously to print flat materials, in particular films and textiles.