Plastic Recycling Melt Homogenization and Filtration

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Solution Overview

Problem

Existing plastic recycling methods often result in end products with compromised mechanical and optical properties due to residual impurities and gas bubbles, which are not effectively removed by conventional filtration and degassing processes.

Innovation Solution

A method and device that sequences processing steps to include homogenization after filtration and before degassing, utilizing intensive shear stress and elevated temperatures to break down and distribute impurities, and introducing cell-forming media to enhance degassing, ensuring a gas-free and agglomerate-free final product.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional filtration and degassing processes are used in sequence, then gas bubbles are removed from the melt, but impurities and agglomerates remain that compromise mechanical and optical properties

Engineering Contradiction:
Improvegas bubblesVSAvoidend product quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by performing homogenization before degassing. The homogenization step breaks down agglomerates and distributes impurities uniformly throughout the melt before the degassing process removes gas bubbles. This sequence ensures that when gas bubbles form during degassing, they are not nucleated around large agglomerates, improving both gas removal efficiency and final product quality.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If filtration is performed before homogenization, then solid foreign matter is removed, but agglomerates and impurities remain distributed unevenly in the melt

Engineering Contradiction:
Improvesolid foreign matterVSAvoiduniform distribution of impurities
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent performs homogenization as a preliminary action after filtration and before degassing. This homogenization step actively breaks down remaining agglomerates and ensures uniform distribution of any residual impurities throughout the melt, creating a stable and homogeneous composition before the final degassing step.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the processing sequence is optimized for gas removal, then degassing efficiency increases, but impurity distribution and product quality deteriorate

Engineering Contradiction:
Improvedegassing efficiencyVSAvoidend product quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary homogenization before degassing to break down agglomerates and uniformly distribute impurities. This preliminary action enhances degassing efficiency by eliminating nucleation sites for gas bubbles, while simultaneously improving end product quality through uniform impurity distribution achieved during homogenization.

Inventive Principle:
Principle #10Preliminary action

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 improves the quality of recycled plastics by effectively removing impurities and gas bubbles, enhancing mechanical and optical properties, and increasing productivity through a continuous, efficient processing chain.

Implementation Method 1

utilizing intensive shear stress and elevated temperatures to break down and distribute impurities

Methodology Applied
Scientific EffectShear stress: Shear Stress

Implementation Method 2

homogenization after filtration and before degassing, utilizing intensive shear stress and elevated temperatures to break down and distribute impurities

Methodology Applied
Scientific EffectHomogenization:

Implementation Method 3

melting of the processed material, at least to the extent that filtration is possible

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

can first be processed in a cutter/compactor at elevated temperature and, if necessary, under a vacuum

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 5

the rest is distributed and crushed in the homogenization section and temperature-sensitive contaminants are caused to decompose by the shear stress that occurs. This gas is eliminated in the subsequent melt degassing

Methodology Applied
Scientific EffectDegassing:

Data Source

PatentEP2853374B1Device for recycling plastics
Publication Date: 2018.01.17 EREMA ENGINEERING RECYCLING MASCHINEN & ANLAGEN GMBH
  • EP2853374B1 patent drawingFigure 1~2
  • EP2853374B1 patent drawingFigure 3a~5

AI summary

The invention relates to a method and an arrangement for recycling plastics comprising the following processing steps: a) preparation of the raw material, wherein the material is, if necessary, crushed and brought into a fluid-like form and, while maintaining its granularity and flowability, heated and continuously mixed, and optionally degassed, softened, dried, its viscosity increased and/or crystallized, b) melting of the processed material, at least to the extent that filtration is possible, c) filtration of the melt to remove impurities, d) homogenization of the filtered melt, e) degassing of the homogenized melt, and f) discharge and/or subsequent processing of the melt, e.g. by granulation, blown film processing, wherein these processing steps follow one another in the specified order (Fig. 2).