Thermal-Mechanical Rubber Granule Devulcanization Process

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for recycling End of Life Tires (ELTs) into rubber granules fail to produce granules of consistent size and purity, leading to polymer degradation and contamination by metals and fibers, making them unsuitable for devulcanization processes and the technical rubber industry.

Innovation Solution

A thermal-mechanical process involving selection, coarse crushing, metal and fiber separation, granulation, curing, and specific sieving and separation techniques to produce high-quality rubber granules that maintain the original polymer composition and remove pollutants, ensuring suitability for devulcanization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing recycling methods are used to produce rubber granules from ELTs, then production cost is reduced, but granule size consistency and purity deteriorate, leading to polymer degradation and contamination

Engineering Contradiction:

Improvegranule size consistency and purityVSAvoidproduction complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The recycling process is divided into multiple sequential stages: pre-treatment (removing beads and treads), granulation with temperature control, magnetic separation for metal removal, and sieving for size classification. Each stage addresses specific requirements to achieve both high precision and feasibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The process controls and adjusts critical parameters including granulator temperature (maintained below 40°C to prevent degradation), rotational speed for size consistency, and magnetic field strength for metal separation. These parameter optimizations enable high-quality output without excessive complexity.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If aggressive mechanical processing is applied to ELTs, then processing speed increases, but polymer degradation and loss of original qualities occur

Engineering Contradiction:

Improveprocessing speedVSAvoidpolymer composition stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The granulation process operates continuously with controlled mechanical action and temperature maintenance, ensuring steady processing without excessive heat generation or polymer degradation. This continuous controlled processing achieves both speed and composition stability.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

Temperature control acts as an intermediary parameter that mediates between mechanical processing intensity and polymer stability. By maintaining temperature below 40°C throughout processing, the system enables faster processing speeds while preserving polymer composition integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If thorough separation processes are implemented to remove metals and fibers, then granule purity improves, but processing time and complexity increase

Engineering Contradiction:

Improvegranule purityVSAvoidprocessing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

Magnetic separation replaces lengthy mechanical screening and manual removal processes for metal extraction. The magnetic field efficiently captures ferromagnetic contaminants in a single pass, significantly reducing processing time while achieving high purity levels.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The process utilizes visual inspection and sorting based on color and texture differences between rubber granules and contaminant fibers. This optical-based separation method quickly removes textile and plastic fibers without adding significant processing time.

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 process produces rubber granules that are chemically and physically stable, free from pollutants, and suitable for devulcanization, enabling their reuse in the technical rubber industry while promoting a circular economy by recycling waste tires effectively.

Implementation Method 1

devulcanization process through a mechanical thermal reaction process

Methodology Applied

Scientific EffectThermal-mechanical reaction: Heating

Data Source

PatentEP4045252B1Process for the production of rubber granules from end of life tires suitable for the devulcanization process through mechanical thermal reactor

Publication Date: 2024.04.03 ECOTYRE SCRL

AI summary

A process is described for the production of rubber granules deriving from "End of Life Tires" (ELTs) suitable for the devulcanization process through a thermal-mechanical process, these ELTs being selected from truck tires and/or agricultural vehicles and/or moving machines - land and/or cars and/or vehicles for light transport, the process comprising the following steps: selection of the ELTs to be treated; coarse crushing of the tire to make a shredded ELT; volumetric reduction of shredded ELT for the production of rough rubber granules; removal of metals from said raw rubber granules; elimination of any textile and/or plastic fibers from said raw rubber granules; selection of rubber granules based on size; curing of rubber granules.