Recording Sheet I-Beam Structure for Ink Jet Print Quality
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Solution Overview
Problem
The use of calcium chloride in ink jet recording media leads to runnability issues in paper machines, interacts negatively with optical brighteners, and affects pH levels in size press formulations, necessitating a solution that maintains ink jet print density and quality without these problems.
Innovation Solution
A recording sheet with an I-beam structure and water soluble divalent metal salts, such as calcium chloride, is developed, which enhances ink jet print density and gamut volume while reducing the overall amount of additives needed, including the use of surface pigments like GCC and PCC to improve dry time and edge acuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If calcium chloride is used to enhance ink jet print density and dry time, then print quality improves, but runnability issues occur in paper machines
Solution Approach 1:
The patent extracts calcium chloride from the size press formulation and applies it only to the recording surface of the paper after sizing. This separation allows the paper machine to operate without calcium chloride (improving runnability) while still achieving the desired print density enhancement on the recording surface.
Solution Approach 2:
The patent applies calcium chloride locally to the recording surface rather than uniformly throughout the paper. This localized application ensures that calcium chloride is present only where needed for ink jet printing, avoiding its negative effects on paper machine runnability and chemical interactions in the bulk paper.
2Manufacturing precision
If calcium chloride is used to improve print density, then ink jet performance enhances, but interaction with optical brighteners occurs
Solution Approach 1:
The patent separates calcium chloride from the size press formulation where optical brighteners are present, and applies it independently to the recording surface. This extraction eliminates the harmful chemical interaction between calcium chloride and optical brighteners while preserving the print density enhancement benefit.
3Manufacturing precision
If calcium chloride is used to enhance print quality, then ink jet performance improves, but pH levels in size press formulation are affected
Solution Approach 1:
The patent removes calcium chloride from the size press formulation, allowing the pH to remain stable and within the optimal range for starch sizing. Calcium chloride is then applied separately to the recording surface, decoupling its print quality benefits from its pH-affecting properties in the size press.
4Manufacturing precision
If high levels of calcium chloride are used to achieve desired print density, then ink jet performance improves, but runnability and chemical interaction problems increase
Solution Approach 1:
The patent concentrates calcium chloride locally on the recording surface where it is needed for ink jet printing, rather than distributing it throughout the bulk paper. This localized concentration achieves the desired print density while minimizing the total amount of calcium chloride used, thereby reducing runnability and chemical interaction problems.
Solution Approach 2:
The patent extracts calcium chloride from the bulk paper formulation and applies it only to the recording surface. This extraction allows high effective concentration at the surface for print density enhancement without the harmful effects associated with high bulk levels.
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 equal or better print density and dry time with significantly lower metal salt levels, improving paper machine runnability and reducing costs without sacrificing performance, and provides enhanced ink transfer and edge acuity.
Implementation Method 1
The use of calcium chloride can be problematic... calcium chloride is currently used in ink jet recording media to enhance inkjet print density
Implementation Method 2
the addition of surface pigments such as GCC (ground calcium carbonate), PCC (precipitated calcium carbonate), and others synergistically improves the gamut volume and dry time
Implementation Method 3
Paper substrates having the so-called, 'I-Beam' structure have been recently developed and are reported to have improved bulk stiffness and/or high dimensional stability
Implementation Method 4
a three-layered single-ply I-Beam structure sheet with a cellulosic central layer and top and bottom layers having starch-based size pressed coatings
Data Source
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AI summary
A recording sheet is provided, which comprises: a paper substrate comprising a plurality of cellulosic fibers; and a sizing agent comprising a water soluble divalent metal salt; wherein the paper substrate and sizing agent cooperate to form an I-beam structure. Methods of making and using the recording sheet are also provided.