Solar Module Enclosing Layer Removal via Mechanical Pre-Processing

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Solution Overview

Problem

Existing solar cell module recycling methods are inefficient, requiring several hours to remove the enclosing layer, which hampers overall recycling efficiency.

Innovation Solution

A method involving mechanical removal of the back sheet and partial mechanical removal of the enclosing layer, followed by immersion in a swelling solution, and subsequent grinding to efficiently separate the enclosing layer from the light-receiving surface layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the module is immersed in peeling liquid to remove the enclosing layer through swelling action, then the enclosing layer can be removed, but several hours to several tens of hours are required, resulting in low recycling efficiency

Engineering Contradiction:
Improveenclosing layer removal completenessVSAvoidrecycling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary mechanical removal (grinding) to remove the back sheet and create openings in the enclosing layer before chemical treatment. This preliminary action exposes the enclosing layer to the peeling liquid through the openings, significantly accelerating the subsequent chemical removal process while ensuring complete removal. The mechanical preprocessing step enables the chemical process to act more effectively and quickly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the enclosing layer removal process into two distinct stages: (1) mechanical removal/grinding stage to remove the back sheet and create openings, and (2) chemical removal stage using peeling liquid through the openings. This segmentation allows each stage to optimize its function, with mechanical methods providing rapid initial removal and chemical methods completing the process efficiently, reducing total time from hours to minutes.

Inventive Principle:
Principle #1Segmentation

2Speed

If mechanical grinding is used to remove the back sheet and form grid slits, then the process can be completed quickly, but the enclosing layer removal still requires lengthy immersion time

Engineering Contradiction:
Improveback sheet removal speedVSAvoidtotal enclosing layer removal time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The mechanical grinding step performs preliminary action by removing the back sheet and creating grid slits/openings in the enclosing layer. This preprocessing is designed specifically to enable rapid subsequent chemical treatment by exposing the enclosing layer to the peeling liquid through the openings, thereby reducing the overall time required for complete enclosing layer removal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The grid slits/openings created by mechanical grinding serve as intermediaries that facilitate the action of the peeling liquid. These openings allow the chemical reagent to penetrate and act on the enclosing layer much more effectively than immersion alone, bridging the gap between mechanical preprocessing and chemical removal to achieve rapid complete removal.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach significantly reduces the time required for removing the enclosing layer, enhancing the overall efficiency of the recycling process and allowing for the reuse of high-purity materials.

Implementation Method 1

immerses the solar cell module in a peeling liquid so as to instill the peeling liquid into the enclosing layer via the slits formed on the surface, thereby causing swelling of the enclosing layer

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP3352227B1Recycling method for solar battery module
Publication Date: 2020.03.25 TOHO KASEI CO LTD
  • EP3352227B1 patent drawingFigure 1
  • EP3352227B1 patent drawingFigure 2
  • EP3352227B1 patent drawingFigure 3(a)~3(f)

AI summary

A method of recycling a solar cell module includes an enclosing layer that encloses a solar cell therein, a light-receiving surface layer laminated on one surface of the enclosing layer, and a back sheet laminated on the other surface of the enclosing layer, the method including: a first removing step of mechanically removing the back sheet; a second removing step of mechanically removing from a side on which the back sheet is removed the entire solar cell and the enclosing layer to such a depth that a part of the enclosing layer having a predetermined thickness remains on the light-receiving surface layer, after the first removing step; and a third removing step of removing the part of the enclosing layer remaining on the light-receiving surface layer by immersion in a solution that causes swelling of the enclosing layer, after the second removing step, thereby improving an overall efficiency.