Aqueous Density Separation for Polymer Purity

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Solution Overview

Problem

Current recycling processes for synthetic organic materials from waste, such as automotive shredder residues and end-of-life durable goods, face challenges in achieving high purity and homogeneous separation of polymers and copolymers due to instability in aqueous separation media and contamination, resulting in purities often below 98%.

Innovation Solution

A process involving alternating densities in successive aqueous separation steps to separate synthetic organic materials into two streams, using intermediate, low, high, and low-density aqueous media to float and settle contaminants and materials, ensuring complete separation and high purity of recycled materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional aqueous separation media are used for density-based separation of synthetic organic materials, then separation into density-based streams is achieved, but the purity of separated materials remains below 98% due to medium instability and contamination

Engineering Contradiction:
Improvepurity of separated materialsVSAvoidstability of aqueous separation medium
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the physical-chemical parameters of the separation medium by introducing surfactants and adjusting density values to achieve stable separation at specific density thresholds (e.g., 0.95 g/cm³, 1.05 g/cm³, 1.15 g/cm³), thereby improving both purity and reliability simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses surfactants as intermediary substances that stabilize the interface between aqueous phases and organic materials, preventing contamination and medium instability, which enables achieving purity above 98% while maintaining reliable separation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If multiple density-based separation steps are performed to increase purity, then material separation improves, but the process complexity and number of separation stages increases

Engineering Contradiction:
Improvepurity of recycled materialsVSAvoidnumber of separation stages
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the separation process into distinct density-based stages with specific threshold values, where each stage targets specific contaminant removal, achieving high purity through systematic division rather than repeated complex operations

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing the density parameters of separation media in a controlled sequence and using surfactants to enhance separation efficiency at each stage, the patent achieves high purity with fewer stages, reducing overall process complexity

Inventive Principle:
Principle #35Parameter 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 process achieves a purity of at least 99% for recycled synthetic organic materials by stabilizing the separation medium and effectively eliminating contaminants, allowing for the production of high-quality polymer granules for industrial reuse.

Implementation Method 1

separation by density which causes the separation of all the synthetic organic materials to be recovered into two streams: one with a density of less than 1, the other, with a density greater than or equal to 1

Methodology Applied
Scientific EffectDensity-based separation: Density Gradient

Implementation Method 2

these variations in density of the aqueous medium causing the selective separation of a determined organic material from the mixture of used materials separated into two streams

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP2334436B1Process for the selective separation, and for the simultaneous increase in purity, of spent, fragmented, organic materials by means of aqueous media having chosen densities
Publication Date: 2015.07.22 GALLOO PLASTICS

AI summary

Process for the selective separation, and for the simultaneous increase in purity, of two spent, fragmented, synthetic organic materials having different densities, mixed together or mixed with various contaminating materials to be eliminated, by means of dense aqueous media, each aqueous medium of which has a chosen density "ds" as threshold for separating said organic materials and contaminants, characterized in that the process comprises: a) a step of separating the mixture into two streams, a supernatant stream (a1) and a settled stream (a2); b) a step of separating the components of the supernatant stream (a1), by eliminating the supernatant fraction and collecting the settled fraction formed from the fragments of the first recyclable spent synthetic organic material; c) a step of separating the components of the settled stream (a2) by collecting the supernatant fraction and eliminating the settled fraction; and d) a step of separating the components of the supernatant stream by eliminating the supernatant fraction and collecting the settled fraction formed from the fragments of the second recyclable spent synthetic organic material.