Frictional Disc Compactor for Mixed Plastic Recycling
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Solution Overview
Problem
Existing methods for recycling waste materials, such as disposable diapers and mixed plastics, face challenges due to the degradation of materials and contamination issues, especially when using screw mixers and varying melting temperatures, leading to environmental impact and loss of commercial value.
Innovation Solution
A system employing frictional heating and a dry compaction process using a knife mill and frictional disc compactor, with controlled temperature and rotation speed, to recycle compound materials without degrading them, and a cooling system that maintains the discs' temperature below polymer degradation points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If screw mixers are used to process mixed plastics, then the materials can be mixed and processed, but the materials undergo degradation due to varying melting temperatures and mechanical stress
Solution Approach 1:
The patent replaces the screw mixer mechanical system with a friction-based heating system using heated plates or drums. This substitution eliminates the mechanical degradation caused by screw mixing while maintaining the ability to process mixed plastics with varying melting temperatures through controlled thermal exposure.
Solution Approach 2:
The patent controls the temperature parameters of the heating surfaces to match the melting points of different plastics being processed. By adjusting and maintaining specific temperature ranges, the system enables processing of mixed plastics without exceeding degradation temperatures, thus preserving material integrity while achieving effective mixing.
2Ease of operation
If wet processing methods are used for compaction, then the material can be processed more easily, but water contamination occurs affecting environmental quality
Solution Approach 1:
The patent extracts and eliminates water from the compaction process entirely. By using dry friction-based heating and compression methods, the system achieves effective material processing without introducing water contamination, thus resolving the contradiction between processing ease and environmental protection.
3Productivity
If high temperatures are used to process plastics with different melting points, then processing efficiency increases, but material degradation occurs
Solution Approach 1:
The patent applies different temperature zones or controlled temperature surfaces that correspond to the melting points of different plastics being processed. This localized temperature control allows each plastic type to melt and process efficiently at its optimal temperature without exposing all materials to excessively high temperatures that would cause degradation.
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 effectively recycles mixed plastics and cellulose-based materials, reducing environmental contamination and enabling the production of raw materials for extrusion, injection, and rotational molding processes, while avoiding material degradation and water usage.
Implementation Method 1
the proposed system comprises the following equipment: a chopper, a mill for homogenization of particle size, a compactor and a cooler of particles by means of circulation of cold water inside the discs
Implementation Method 2
a cooler of particles by means of circulation of cold water inside the discs
Data Source
AI summary
This description relates to the reuse of waste materials based on synthetic resins and, more specifically relates to the reuse of disposable diapers, plastic packaging (PVC, PP, PET, and so on), for the production of raw material for extrusion, lamination, injection and rotational molding processes, among others. A system comprises a chopper, a mill for homogenization of particle size, a disc compactor employing frictional heating between a fixed disc and a rotating disc and cooling by circulation of cold water inside the discs.