Fluorescent Markers for Plastic Sorting and Equipment Protection

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Solution Overview

Problem

Existing plastic recycling processes are hindered by foreign substances like glass fibers and additives in materials, which cause abrasive damage to equipment and complicate uniform recycling, necessitating early detection and separation.

Innovation Solution

Incorporating fluorescent compounds, such as Anti-Stokes-crystals, into the plastic materials to enable reliable detection and separation through fluorescence excitation and detection, allowing for sorting based on specific excitation energies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If foreign substances are contained in the plastic material, then the material has specific composition requiring separation, but the foreign substances have abrasive effect causing rapid damage to extruder and filter apparatuses

Engineering Contradiction:
Improvematerial composition flexibilityVSAvoidequipment durability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by adding fluorescent markers to the plastic material before recycling processing. This allows the material to be pre-marked with detectable substances that enable early identification and separation of foreign substances, preventing them from causing abrasive damage to equipment during subsequent extrusion and filtration processes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fluorescent compounds serve as intermediaries between the plastic material and the detection system. These markers absorb specific wavelengths of light and emit fluorescent signals that can be detected by sensors, enabling indirect detection of material composition without direct contact between detection equipment and abrasive foreign substances

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If all formulations of plastic material are processed uniformly and jointly for re-use as recycled granules, then economic efficiency is improved, but glass fibres in recycled granules may not be economically desirable or suitable for product strategy

Engineering Contradiction:
Improverecycling efficiencyVSAvoidproduct quality control
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies extraction by using fluorescent markers to identify and separate materials containing foreign substances from the bulk plastic material. This enables selective removal of unwanted materials (such as glass-fibre-reinforced PVC) from the recycling stream, allowing uniform processing of suitable materials while excluding those that would compromise product quality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by enabling different sorting outcomes for different portions of the input material. Materials with fluorescent markers (indicating foreign substances) are separated and directed to different processing paths or rejected, while materials without markers proceed to uniform recycling, ensuring that only appropriate materials are processed together

Inventive Principle:
Principle #3Local quality

3Reliability

If detection and separation of plastic materials containing foreign substances is performed at the earliest possible stage, then equipment damage is prevented, but reliable detection must be achieved without altering material properties or requiring complex settings

Engineering Contradiction:
Improvedetection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or chemical analysis systems with an optical detection system based on fluorescence. The fluorescent markers provide clear optical signals that can be detected by simple sensors, eliminating the need for complex mechanical disassembly or chemical testing while achieving reliable detection at the earliest stage

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes fluorescence (a form of light emission/color change) as a detection mechanism. The fluorescent markers absorb specific wavelengths of light and emit visible fluorescence, providing a clear visual signal that can be easily detected by optical sensors without requiring complex analysis of material properties

Inventive Principle:
Principle #32Color changes

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 use of fluorescent markers ensures reliable and efficient detection and separation of materials containing foreign substances, maintaining equipment integrity and enabling uniform recycling without altering the material's properties or requiring complex camera settings.

Implementation Method 1

the material comprises at least one fluorescent compound

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

the fluorescent compound comprises Anti-Stokes-crystals or -pigments

Methodology Applied
Scientific EffectAnti-Stokes fluorescence: Fluorescence

Data Source

PatentUS10717113B2Material having a marker, and method for sorting a mixture of materials
Publication Date: 2020.07.21 POLYSECURE

AI summary

The present invention relates to a material, preferably a plastic material, comprising foreign substances, characterised in that the material further comprises fluorescent compounds, and a process for sorting a mixture of materials.