Foam Fiber Suspension Loop for Nonwoven Foam Migration Control
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Solution Overview
Problem
Managing and handling foam in nonwoven material production systems is challenging due to foam migration, leading to process degradations and downtime, as well as the need for additional surfactant and foam addition throughout the system.
Innovation Solution
A system and process that includes a pulper to generate foam, a headbox to displace foam-suspended fiber stock onto a forming wire, and a foam return device to recover foam from the forming wire and return it to the pulper, maintaining uniform fiber distribution and minimizing the need for additional surfactant or foam addition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If foam is used to suspend fiber stock in the pulper, then fiber suspension is improved, but foam migrates to unwanted areas causing process degradation and downtime
Solution Approach 1:
The patent extracts the harmful foam from the system by introducing a defoaming agent that selectively removes foam from unwanted areas (forming wire, press section, dryer) while preserving the foam suspension function in the pulper. This separation allows the system to maintain fiber suspension benefits without suffering from foam migration problems.
Solution Approach 2:
The patent applies different foam management strategies to different locations: foam is maintained in the pulper for fiber suspension, while defoaming agents are applied locally at the forming wire, press section, and dryer to prevent foam-related problems in those specific areas. This localized approach allows simultaneous optimization of suspension and problem prevention.
2Stability of the object's composition
If additional surfactant is added throughout the system to maintain foam, then foam suspension is maintained, but system complexity and chemical usage increase
Solution Approach 1:
The patent implements a foam return system where foam that has completed its function of suspending fibers is collected and returned to the pulper to be regenerated. This self-circulating system maintains foam suspension stability without requiring continuous addition of surfactant throughout the entire system, reducing both chemical usage and system complexity.
Solution Approach 2:
The patent creates a continuous foam circulation loop where foam is constantly regenerated in the pulper and reused after returning from the forming section. This continuous regeneration approach maintains suspension stability more efficiently than discrete surfactant additions at multiple points, simplifying the overall system.
3Stability of the object's composition
If foam is allowed to accumulate in the system, then fiber suspension is maintained, but clean-up time and costs increase
Solution Approach 1:
The patent applies defoaming agents in advance at critical points (forming wire, press section, dryer) to prevent foam accumulation before it becomes problematic. This preliminary action stops foam from building up to levels that would require time-consuming clean-up operations, while the foam return system continuously manages foam levels.
Solution Approach 2:
The foam return system creates a feedback loop that continuously monitors and manages foam levels throughout the system. By returning foam to the pulper and maintaining controlled foam circulation, the system prevents excessive foam accumulation that would trigger clean-up requirements, reducing downtime while maintaining effective fiber suspension.
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 system controls foam spread, reduces clean-up time and costs, and creates a closed-loop system for managing foam, ensuring uniform fiber distribution and reducing surfactant and foam requirements.
Implementation Method 1
a pulper configured to (i) accept surfactant, a liquid and fiber stock and (ii) generate a foam that suspends the fiber stock
Implementation Method 2
a foam return device that removes at least some of the foam from the forming wire and returns the at least some of the foam to the pulper
Data Source
AI summary
A system comprising a pulper configured to (i) accept surfactant, a liquid and fiber stock and (ii) generate a foam that suspends the fiber stock, wherein the foam has a half-life; a headbox configured to receive the foam-suspended fiber stock from the pulper and displace the foam-suspended fiber stock onto a forming wire, wherein a time it takes the foam-suspended fiber stock to move from the pulper to the headbox is less than the half-life; and a foam return device that removes at least some of the foam from the forming wire and returns the at least some of the foam to the pulper.