Absorbent Article Recycling via Swelling and Physical Shock
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Solution Overview
Problem
Existing methods for recycling absorbent articles, such as paper diapers, face challenges in efficiently recovering structural members like films and absorbent body materials due to debris production during disintegration, which complicates separation and reduces recovery rates.
Innovation Solution
A method involving pretreatment with water to swell the absorbent article, followed by physical shock in a rotary drum to disintegrate it into film and absorbent body material while maintaining the film's original shape, and subsequent separation using acidic solutions and solvents to isolate components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the used absorbent article is broken up into chips before disintegration, then the disintegration process can be performed, but debris is produced at the broken sections which mixes with drainage and reduces recovery rate of structural members
Solution Approach 1:
The absorbent article is subjected to swelling treatment with water before disintegration, which causes the article to expand and creates internal stress that facilitates cleaner separation during subsequent disintegration, preventing debris formation at broken sections
Solution Approach 2:
The physical state of the absorbent article is changed by swelling it with water, transforming it from a compact dry state to an expanded wet state, which alters the structural integrity and enables controlled disintegration without producing debris
2Productivity
If the absorbent article is disintegrated in a disintegrating drum, then the pulp components and non-pulp components can be separated, but additional debris is produced from broken sections due to rotational shock
Solution Approach 1:
The absorbent article undergoes preliminary swelling treatment before being subjected to rotational shock in the disintegrating drum, which prepares the structure to disintegrate more cleanly and reduces additional debris production during drum rotation
Solution Approach 2:
The rotational shock that would normally produce debris is converted into a beneficial force by first swelling the article, causing the internal structure to separate along predetermined planes rather than creating random debris at broken sections
3Productivity
If the chips are made smaller to improve disintegration, then the pulp and non-pulp components become more uniform in size, but this makes them more difficult to distinguish and separate
Solution Approach 1:
The disintegration process is made selective by swelling the article first, which causes different components to separate at different rates and to different extents, maintaining size differentiation between pulp and non-pulp components even during thorough disintegration
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
This method allows for efficient recovery of structural members like films and absorbent body materials without breaking up the absorbent article, improving separation efficiency and purity.
Implementation Method 1
a pretreatment step of swelling the used absorbent article with water
Implementation Method 2
a disintegration step of applying physical shock to the swelled used absorbent article to disintegrate the used absorbent article into at least the film and the absorbent body material
Implementation Method 3
allowing the absorbent article to fall by gravity from the upper area to the lower area, thus impacting with an inner wall of the rotary drum
Implementation Method 4
a separating step of separating the disintegrated film and absorbent body material while maintaining the original shape of the film
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3(a)~3(c)
AI summary
A method is provided which, when recycling constituent members of an absorbent article, enables efficiently recovering the constituent members from the absorbent article without rupturing the absorbent article. This method is for recovering constituent members from an absorbent article (1) which is provided with a front surface sheet (2), a back surface sheet (3), and an absorbent body (4) arranged between the front surface sheet and the back surface sheet, wherein the front surface sheet and/or the back surface sheet contains a film as a constituent member and the absorbent body contains an absorbent body material as a constituent member. This method involves a pretreatment step (S1) for soaking and swelling the absorbent article with water, a disintegration step (S2) for applying a physical impact to the swelled used absorbent article to disintegrate the used absorbent article into at least a film and an absorbent body material while maintaining their original shapes, and a separation step (S3) for separating the disintegrated film and absorbent body material while maintaining their original shapes.