Recycled Plastic Sorting and Marker Control System
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Solution Overview
Problem
The challenge lies in ensuring accurate control and proportioning of recycled material in plastic products, particularly due to the need for consistent marker concentrations and efficient sorting of plastics by type and intended use, which existing technologies struggle with, especially in cost-effective and practical terms.
Innovation Solution
A method and system utilizing a transmitter/receiver unit with IR, white light, and UV sources to detect and sort plastics based on their type, color, and intended use, adjusting marker concentrations dynamically, and employing blow-out nozzles for segregation, while ensuring accurate detection without paper labels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed quantity of master batch with predetermined marker concentration is added to recycled material, then the marker concentration control is simplified, but the marker concentration becomes excessive in recycled material over time leading to manipulation concerns
Solution Approach 1:
The system employs a feedback mechanism where the actual marker concentration in recycled material is continuously measured and used to adjust the master batch addition quantity. The control unit calculates the required master batch amount based on the difference between target and actual marker concentrations, ensuring precise control while preventing excessive marker accumulation over time.
Solution Approach 2:
The system transitions from a static fixed-quantity addition approach to a dynamic adjustment approach. The master batch addition quantity is continuously adapted based on real-time marker concentration measurements, allowing the system to respond to variations in recycled material batches and maintain precise marker concentration control.
2Measurement precision
If infrared cameras are used for plastic sorting, then sorting accuracy is improved, but the cost and complexity of the system increases significantly
Solution Approach 1:
The system replaces expensive infrared cameras with more cost-effective optical detection devices. While infrared cameras provide high sorting accuracy, they are prohibitively expensive for many applications. The patent uses alternative optical methods that achieve sufficient sorting accuracy at a much lower cost, making the technology accessible for widespread deployment in recycling facilities.
Solution Approach 2:
The system uses optical properties and reflection patterns as substitutes for direct infrared spectral analysis. By analyzing the way different plastics reflect light in the visible and near-infrared ranges, the system can identify plastic types without requiring expensive thermal infrared cameras, effectively creating a lower-cost copy of the high-accuracy sorting capability.
3Measurement precision
If multiple detection units are added to monitor marker concentration throughout the manufacturing process, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The monitoring system is divided into discrete detection units positioned at different stages of the manufacturing process. Each detection unit independently measures marker concentration at its specific location, and the control unit integrates these segmented measurements to achieve comprehensive monitoring with high precision while keeping individual unit complexity low.
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 enables precise control of recycled material proportions, cost-effective sorting of plastics, and prevents contamination by ensuring accurate identification and segregation of plastics by type and intended use, reducing marker accumulation and enhancing operational efficiency.
Implementation Method 1
a first detection unit (508) for detecting a concentration of marker particles (M) in the fed first plastic raw material (506) by means of an intensity of luminescence
Implementation Method 2
the wavelength range used is divided into several transmission bands (optical windows), and the transmission and reflection within each optical window are detected
Implementation Method 3
employing blow-out nozzles for segregation
Data Source
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AI summary
The invention relates to various systems and methods for sorting plastics and for producing plastic material on the basis of sorted recycling material. According to one aspect, a type of plastic object is determined by detecting the intensities of reflected light in the infrared range at different wavelengths, and then the plastic objects are sorted according to the types in question. According to another aspect, a concentration of a marker in a plastic material (502) made from recycled plastic raw material is determined and, on the basis thereof, a suitable quantity of additional markers is introduced in order to obtain a constant marker concentration.