Fluff Pulp Production Without Bleaching
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Solution Overview
Problem
The high cost, environmental impact, and resource intensity of bleaching processes in producing fluff pulp for applications such as hygiene products and airlaid nonwovens, which require adequate absorption properties.
Innovation Solution
Producing fluff pulp using a process that includes preparing sulphate pulp, washing and screening, oxygen delignification, and drying, without the need for bleaching, thereby reducing chemical and energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If bleaching is used to increase brightness and improve appearance of fluff pulp, then ISO brightness is improved (reaching 85-94%), but production cost increases, environmental impact worsens, and resource consumption increases
Solution Approach 1:
The patent extracts and removes the bleaching step from the conventional pulp production process. By taking out the bleaching operation entirely, the invention achieves adequate fluff pulp properties (absorption, brightness in range 30-60% ISO, specific volume ≥19 dm³/kg) without using bleaching chemicals, thereby reducing chemical consumption and environmental impact while maintaining functional performance
Solution Approach 2:
The patent changes the target parameter range for ISO brightness from the conventional 85-94% down to 30-60%, and sets the Kappa number target at 5-18. This parameter change reflects that adequate absorption properties can be achieved without high brightness, allowing production to proceed without expensive and environmentally harmful bleaching processes
2Illumination intensity
If multiple bleaching steps and chemicals are used to reach desired brightness level, then ISO brightness is improved, but production cost increases and manufacturing complexity increases
Solution Approach 1:
The patent removes the entire bleaching sequence from the production process, eliminating multiple bleaching steps and the associated chemicals (oxygen, hydrogen peroxide, ozone, peracetic acid, chlorine dioxide). This extraction simplifies manufacturing and reduces production cost while achieving adequate properties through controlled delignification to Kappa number 5-18
Solution Approach 2:
Instead of following the conventional approach of over-bleaching to achieve high brightness (85-94% ISO) and then accepting the cost penalty, the patent inverts the approach by targeting moderate brightness (30-60% ISO) and adequate delignification (Kappa 5-18) from the outset, eliminating the need for extensive bleaching and thereby reducing production cost
3Illumination intensity
If bleaching processes are used to remove lignin and colored compounds, then brightness is improved, but environmental impact worsens and resource consumption increases
Solution Approach 1:
The patent converts the conventional approach of using harmful bleaching chemicals into a beneficial process by using controlled oxygen delignification to achieve adequate brightness (30-60% ISO) and Kappa number (5-18) without the environmental harm of extensive bleaching. The moderate delignification level achieved is sufficient for absorption applications while avoiding the environmental damage associated with strong bleaching chemicals
Solution Approach 2:
The patent extracts and eliminates the harmful bleaching chemicals (oxygen, hydrogen peroxide, ozone, peracetic acid, chlorine dioxide) from the production process. By removing these environmentally harmful substances and replacing them with a controlled delignification process targeting Kappa number 5-18, the invention significantly reduces environmental impact while maintaining adequate product performance
4Illumination intensity
If extensive bleaching is used to achieve high brightness, then appearance is improved, but energy consumption increases
Solution Approach 1:
The patent changes the target brightness parameter from high (85-94% ISO) to moderate (30-60% ISO) and targets a Kappa number of 5-18 through delignification. This parameter change eliminates the need for energy-intensive bleaching processes while achieving adequate properties for absorption applications, thereby significantly reducing energy consumption
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
Achieves fluff pulp with desired properties such as Kappa number, ISO brightness, specific volume, and absorption time, while significantly reducing resource consumption and environmental impact.
Implementation Method 1
oxygen delignification
Data Source
AI summary
The present invention is directed to fluff pulp having a Kappa number in the range of from 5 to 18 and having, when in the form of a dry sheet, ISO brightness in the range of from 30 to 60% and having a specific volume in the dry defibrated state of at least 19 dm3/kg and having absorption time in the range of from 2 to 4 seconds.