Softwood Pulp Filter Paper for Aqueous Extracts
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Solution Overview
Problem
Existing filter papers for producing aqueous extracts, such as tea or coffee, rely heavily on abacá or sisal fibers, which are costly and of variable quality, making their production difficult and expensive, and attempts to replace them with other fibers have been unsuccessful in achieving comparable performance.
Innovation Solution
A filter paper composed primarily of softwood pulp, with a specific property profile including a basis weight of 9.0-13.5 g/m², density of 280-350 kg/m³, and air permeability of 17000-26000 cm/(min·kPa), and minimal or no abacá or sisal fibers, achieved through a mechanical treatment process that includes compression and high moisture content, allowing for industrial production and efficient extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If abacá fibers or sisal fibers are used to produce filter paper, then high and uniform porosity and high strength can be achieved, but production becomes costly and difficult due to limited suppliers and variable quality
Solution Approach 1:
The patent changes the fundamental material parameter from natural fibers (abacá/sisal) to softwood pulp, and adjusts physical parameters including basis weight (9.0-13.5 g/m²), density (280-350 kg/m³), and air permeability (17000-26000 cm/(min·kPa)) to achieve comparable performance with easier manufacturing
Solution Approach 2:
The patent replaces expensive, hard-to-source natural fibers with cheaper softwood pulp that can be produced reliably by industrial pulping processes, eliminating dependency on limited natural fiber suppliers while maintaining acceptable filter paper performance
2Strength
If abacá fibers or sisal fibers are used, then high strength and uniform porosity are achieved, but the filter paper releases undesirable substances into water
Solution Approach 1:
The patent uses softwood pulp which is chemically stable and does not release undesirable substances, replacing natural fibers that may leach compounds into the beverage, while maintaining sufficient mechanical strength through optimized basis weight and density parameters
3Productivity
If filter paper is made with high porosity for fast water flow, then extraction speed increases, but small particles may fall through the filter paper
Solution Approach 1:
The patent optimizes the balance between porosity and particle retention by controlling basis weight (9.0-13.5 g/m²) and density (280-350 kg/m³), achieving sufficient porosity for fast water flow while maintaining pore structure that prevents particle passage through the filter paper
4Productivity
If filter paper has low basis weight for high porosity, then water flow is improved, but mechanical strength decreases
Solution Approach 1:
The patent finds the optimal parameter combination where basis weight is kept low (9.0-13.5 g/m²) to maintain high porosity and water flow, but density is increased (280-350 kg/m³) through compression treatment to compensate and maintain adequate mechanical strength for handling and filtration
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 filter paper maintains performance comparable to conventional papers while reducing costs and quality variability, enabling faster extraction and increased productivity with fewer reel changes, without compromising mechanical strength or air permeability.
Implementation Method 1
the water can easily flow around the material to be extracted by natural or forced convection
Data Source
AI summary
Described herein is a filter paper for the production of an aqueous extract, comprising softwood pulp, which has the following properties: a basis weight of more than 9.0 g/m2 and less than 13.5 g/m2, a density of more than 280 kg/m3 and less than 350 kg/m3, a roughness of more than 700 ml/min and less than 1300 ml/min, a bending resistance in the machine direction of more than 50 mN and less than 75 mN, and an air permeability of more than 17000 cm/(min·kPa) and less than 26000 cm/(min·kPa), wherein the filter paper is either free from abacá fibers and sisal fibers or, if abacá fibers and/or sisal fibers are present, taken together they make up less than 20% of the paper mass.