Polypropylene Recovery Process Using Cold Mechanical Compaction
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Solution Overview
Problem
Existing processes for recovering plastic materials, such as polypropylene, often require hot steps that compromise the chemical-physical quality of the recovered material and result in high energy consumption, making them costly and inefficient.
Innovation Solution
A process that treats plastic waste as flakes mixed with air, compacting and extruding them without water, using a sequence of steps that includes forced flow and extrusion to achieve high productivity with limited energy consumption, thereby avoiding hot thickening and optimizing chemical-physical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hot thickening process is used to increase specific weight and obtain compliant Secondary Raw Materials, then the material meets standard requirements, but the chemical-physical characteristics of the recovered material deteriorate and energy consumption increases
Solution Approach 1:
The invention changes the temperature parameter from hot (traditional process) to cold (innovative process), transforming the thickening process from thermal to mechanical. This parameter change maintains compliance with UNIPLAST UNI 10667 Standard while preserving the chemical-physical characteristics of the recovered polypropylene material.
Solution Approach 2:
The invention replaces the thermal system (hot thickening with water and heat) with a mechanical system (cold thickening through mechanical action). This substitution eliminates the need for thermal energy while achieving the same thickening effect, thereby maintaining standard compliance without degrading material quality.
2Quantity of substance
If hot thickening process is used to thicken plastic waste, then the material reaches required density, but energy consumption increases significantly
Solution Approach 1:
The invention replaces the thermal system (heating to achieve thickening) with a mechanical system (cold thickening through mechanical action). This substitution eliminates the need for thermal energy while achieving the same thickening effect, thereby maintaining required specific weight without significant energy consumption.
Solution Approach 2:
The invention changes the energy type parameter from thermal energy to mechanical energy, transforming the thickening mechanism. This parameter change achieves the required specific weight through mechanical action rather than thermal input, significantly reducing overall energy consumption.
3Stability of the object's composition
If cold working process is used to maintain chemical-physical characteristics, then material quality improves, but the ability to achieve required thickness and density is compromised
Solution Approach 1:
The invention changes the thickening mechanism parameter from thermal to mechanical, enabling cold working that both preserves chemical-physical characteristics and achieves required specific weight and thickness through enhanced mechanical action.
Solution Approach 2:
The invention applies preliminary mechanical preparation to the plastic waste before thickening, which facilitates subsequent cold thickening. This preliminary action enables the material to reach required density and thickness through mechanical means while maintaining its chemical-physical characteristics.
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 reduces energy requirements by at least 30% compared to traditional methods, while improving the quality of the recovered plastic material by eliminating hot steps and maintaining better chemical-physical characteristics through cold working.
Implementation Method 1
US2002/0125600 A1 teaches a plastic recycling system including a first granulator for reducing plastic waste to a first particle size and a second granulator for reducing plastic waste to a second size. The above known system provides a frictional melting structure for melting the first particles and the second particles.
Implementation Method 2
a compaction cell (15) arranged to compact the flakes
Implementation Method 3
a forced flow cell (16) arranged to receive the compacted flakes at an inlet, and force the compacted flakes towards an outlet
Implementation Method 4
the extruder (18) is arranged to mix the flakes with additives and mineral fillers
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
A process (100) for recovering plastic material, in particular polypropylene plastic material, comprising in sequence at least the steps of: shredding and reducing the material to be recovered into flakes of predetermined dimensions (120), transporting the flakes in the shape of flakes mixed with air (130), mixing the flakes mixed with air (210), transport and weigh the flakes mixed with air (220), compacting and dosing the flakes mixed with air (230), realizing a forced feeding of materials comprising compacted flakes free of air, process materials and additives (240), extruding both the materials exiting the forced feeding step (240) and mineral fillers provided to complete the recovery process of the plastic material. The invention also relates to a plant for carrying out the process (100).