PCC Filler Blending for Supercalendered Paper Printability
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Solution Overview
Problem
PCC-filled supercalendered papers exhibit increased porosity due to their spheroidal structure, leading to printing issues such as piling and picking, which affect print quality and increase wear on printing equipment, while clay-filled papers provide better printability but with different pore structures.
Innovation Solution
Blending fine non-platy PCC with larger non-platy PCC to achieve a porosity similar to clay-filled papers, using ULTRAFINE PCC, which reduces porosity and improves printability without compromising optical and mechanical properties like brightness and gloss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If PCC is used as filler in supercalendered papers, then whiteness and brightness are improved, but porosity increases leading to poor printability
Solution Approach 1:
The patent applies parameter changes by modifying the particle size distribution of PCC filler, using a blend of fine and larger non-platy particles instead of uniform particles. This changes the physical parameters of the filler to reduce porosity while maintaining brightness, thereby improving printability without sacrificing optical properties.
Solution Approach 2:
The patent uses composite materials by creating a filler blend combining fine non-platy PCC and larger non-platy PCC particles. This composite filler system leverages the advantages of different particle sizes and shapes to achieve both low porosity for good printability and high brightness from the PCC content.
2Illumination intensity
If PCC-filled supercalendered papers are used, then whiteness is improved, but piling and picking issues increase affecting print quality
Solution Approach 1:
The patent changes the particle size distribution parameter of PCC filler to a bimodal distribution with fine and larger particles. This parameter modification reduces the excessive porosity that causes ink absorption issues, thereby eliminating piling and picking problems while preserving the whiteness provided by PCC.
Solution Approach 2:
The patent converts the potentially harmful effect of high porosity (which causes poor printability) into a benefit by using a controlled blend of particle sizes. The larger particles provide structural support to reduce excessive porosity while fine particles maintain the brightness, thus converting the porosity problem into a solution for both whiteness and print quality.
3Manufacturing precision
If clay is used as filler, then printability is improved, but PCC cannot provide the same level of whiteness and brightness
Solution Approach 1:
The patent merges the advantages of clay fillers (good printability due to lower porosity) with the advantages of PCC (superior whiteness and brightness). By combining fine and larger non-platy PCC particles in specific proportions, the filler blend achieves clay-like porosity for good printability while maintaining PCC's optical properties.
Solution Approach 2:
The patent changes the filler composition from pure clay or uniform PCC to a blended system with controlled particle size distribution. This parameter change enables the filler to exhibit both the low porosity characteristics of clay (improving printability) and the high brightness characteristics of PCC.
4Ease of manufacture
If high percentages of mineral fillers are used in supercalendered papers, then economics are improved and surface smoothness is enhanced, but porosity increases reducing printability
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution of the filler blend. Using a combination of fine and larger non-platy PCC particles allows high filler content (for economics and smoothness) while controlling porosity to maintain good printability, thus resolving the contradiction between manufacturing cost and print quality.
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 blending of PCC types reduces porosity and improves printability, addressing piling and picking issues while maintaining optical and mechanical properties, enhancing the overall performance of supercalendered papers.
Implementation Method 1
Blending fine non-platy PCC with larger non-platy PCC to achieve a porosity similar to clay-filled papers
Data Source
AI summary
A method of blending a fine precipitated calcium carbonate (PCC) filler with larger PCC, the resulting blend to be used alone or in conjunction with a ground carbonate, clay or other filler, resulting in improved porosity by the lowering of the porosity of supercalendered paper, thereby imparting improved and offset printability. The fine PCC can be ultrafine PCC filler which then is blended with other fillers including but not limited to pigments. These fillers which are blended with the fine PCC include commercial and experimental PCC and commercial clays. Ultrafine PCC has agglomerates of small, discrete particles. Ultrafine PCC for use in the invention has a specific surface area of about 20 m2/g as measured by BET gas adsorption. As measured by a sedigraph, the average size of these agglomerates is from 0.4 to 1.1 microns.