Identification and waste sorting in recycling by NIR technology

Recycling has become a major industry in all developed countries, to reduce ecological damage and save valuable resources. Municipal waste management strategies incorporate the collection of useful materials like plastic packaging, used paper, glass and electronic scrap in addition to household waste. In the industrial recycling process, all these material streams must be processed further for thermal utilisation or for re-entering the cycle. The following applications describe different recognition and identification of different materials in sorting processes by using NIR technology:

Identification and sorting of plastics from household waste

Identification of plastics from household waste in recycling
Identification of plastics from household waste in recycling

The NIR spectrometer KUSTA1.9MPL-24V and NIR cameras KUSTA1.7MSI & KUSTA1.9MSI in combination with module idHwaste

The analytical software module idHwaste is optimised for the material and requirements for the identification and sorting of household waste. The software identifies all plastics, which are used as food packages and frequently appearing technical polymers e.g. polyamide (PA).

Due to the high spectral resolution of the device KUSTA1.9MPL-24V plastic composites, e.g. PET bottles with PVC foil labels are identified reliably. Therefore, the application module is ideally suited for the PVC elemination in Bottle-to-Bottle recycling.

The hyperspectral cameras KUSTA1.7MSI and KUSTA1.9MSI are preferred for applications requiring a high spatial and temporal resolution. For frame rates of up to 795 Hz, KUSTA1.9MSI also identifies small material fractions with high reliability at high conveyor belt speeds.

Comparison NIR-measurement equipment in plastic recycling

NIR technology
KUSTA1.9MPL-24V KUSTA1.7MSI KUSTA1.9MSI
Size of plastic parts > 30 mm > 2 mm > 2 mm
Number of measurement tracks 64 318 192
Probe line / illumination Probe line PMAmpl Illumination PMAmsi Illumination PMAmsi
Conveyor belt width Up to 2800 mm Up to 2000 mm* Up to 2000 mm*
Optionals RBG sensor,
hand scanner,
single measurement positions
Mirror unit,
installation bridge,
RGB-camera
Mirror unit,
installation bridge,
RGB-camera
Paper sorting/
PVC-identification
Yes /
Yes
Yes /
No
Yes /
Yes
Process interface TCP/IP, UDP, RS232 TCP/IP, UDP TCP/IP, UDP

* Optional possible are double-camera setups up to 2800 mm width.


Technical data

Identification and sorting of waste electronic plastics (WEEE)

Identification and sorting of electronic plastic (WEEE)
Identification and sorting of electronic plastic (WEEE)

The NIR spectrometer KUSTA1.9MPL-24V and NIR cameras KUSTA1.7MSI & KUSTA1.9MSI in combination with module idEwaste

The analytical software module idEwaste was developed for sorting of technical plastics (Waste Electrical and Electronic Equipment WEEE). The software module contains all technically relevant plastics and blends and is optimised for the recycling of the plastics in electronic waste. For sorting and recycling of printed circuit boards idPCB should be used.


The identification module idEwaste is offered in two versions:
the KUSTA1.9MPL-24V standard version for fraction sizes from 30 mm and
KUSTA1.7MSI and KUSTA1.9MSI
high-speed version idEwaste (flakes) for smaller fraction sizes.
In this case, the high spatial and temporal resolution of the KUSTAx.xMSI spectrometer allows sorting of shredded flakes2 mm in size.


Technical data

Recycling and sorting of printed circuit boards (PCB)

Sorting & recycling of printed circuit boards
Sorting & recycling of printed circuit boards

The NIR spectrometer KUSTA1.9MPL-24V and NIR camera KUSTA1.9MSI in combination with module idPCB

The analytical software module idPCB is an enhanced idEwaste for Waste Electrical and Electronic Equipment (WEEE). The module idPCB identifies all technical plastics used in consumer electronics in addition to different sorts of printed circuit boards (PCB). After the sorting process, the valuable raw materials (precious metals) may be recovered.


The module is available in two versions:
■ for KUSTA1.9MPL-24V up to fraction sizes > 30 mm and
■ for KUSTA1.9MSI up to fraction sizes 2 - 30 mm

Technical data

Recycling & sorting of PET flakes

Sorting & recycling of PET flakes
Sorting & recycling of PET flakes

The NIR camera KUSTA1.9MSI in combination with module idPET-Flakes

The analytical software module idPET-Flakes is used to eliminate impurities in Bottle-to-Bottle recycling of PET bottles. In addition to all common household plastics, the module also identifies impurities like PA or silicone. The latter often occurs in gaskets of bottle caps. The software module is optimised for the high frame rates of KUSTA1.9MSI and identifies in particular PVC with the highest sensitivity. After sorting with idPET-Flakes, the material is therefore virtually PVC-free.


Technical data

Input material Shredded PET bottles (flakes)
Belt width 1024 mm
Sorting speed Max. 1 - 3 m/s
Fraction size 3 - 20 mm

Recycling & sorting of waste paper

Sorting & recycling of paper by sensor-based technology
Sorting & recycling of paper by sensor-based technology

The NIR spectrometer KUSTA1.9MPL-24V and NIR camera KUSTA1.9MSI in combination with module idPaper

Waste paper is an important raw material for the production of virgin paper. Non-paper material (e.g. plastics, liquid packing board) as well as objectionable paper sorts (e.g. cardboard, printed packages) need to be eliminated from the material stream prior to deinking. The presently used RGB sensors cannot identify coloured printed packages correctly because the colour characteristics of printed packages and high quality print products (e.g. journals) are identical to each other.

A solution for this problem is offered by the software module idPaper, which established itself in recent years and became a quasi standard. Contrary to visible light, the NIR radiation has a higher depth of penetration (few tenth of a millimetre). The coating of printed cardboards can be penetrated, therefore the layers below can be analysed and identified.

Each paper type has a characteristic NIR spectrum, which is identified by idPaper. The paper is finally classified according to the list of the "European List of Standard Grades of Recovered Waste paper and Board" (EN 643).

The module is available in two versions:
■ the standard version for KUSTA1.9MPL-24V and
■ the high-speed version for KUSTA1.9MSI. In this case, the high spatial and spectral resolution of the NIR camera KUSTA1.9MSI enables the use of extensive object recognition algorithms, increasing the identification accuracy significantly.

Input material Waste paper from household or commercial waste collections
Paper (Deinking) Office paper, magazines, newspapers, catalogues
Papier (No-Deinking) Cardboards, folding box
Optionals Identification of shrinkwrapped brochures, reducing deinking lost
Plastics PET, PE, PP, PS, PVC

Identification and sorting of waste paper in recycling (PDF)

Process optimisation by input monitoring of used-paper

Input monitoring of used-paper by NIR analysis
Input monitoring of used-paper by NIR analysis

The added value of a used-paper sorting plant can be increased significantly by matching important process parameters precisely to the composition of the input material. Hereby the maximum sorting speed and efficiency of the plant can be reached.

The key parameters for system control are the fractions of:
■ deinking material
■ plastic and other unwanted material
■ paperboard and cardboard
■ humidity
in the input stream.

With the imaging NIR hyperspectral camera KUSTA1.9MSI, LLA Instruments GmbH has developed a system, that captures these parameters and provides a network interface to the system controller.

This allows an adaption to the input material with regard to the:
■ plant throughput
■ programs of sensor-based sorting aggregates
■ settings to disc or drum screens

A documentation and quality control of various suppliers is also now possible with the system.

Example: analysis of the used-paper composition for process optimisation

Process image of used-paper analysis by NIR

Sorting & identification of extraneous material in C&D recycling

Sorting & identification of extraneous material in C&D recycling
Sorting & identification of extraneous material in C&D recycling

The NIR hyperspectral imaging camera KUSTA2.2MSI and NIR spectrometer KUSTA2.2MPL-24V in combination with module idDebris

Sorting & identification of fractioned RC-construction material in C&D recycling

Identification of fractioned RC-construction material in C&D recycling
Identification of fractioned RC-construction material in C&D recycling

Identification & detection of asbetos in recycling

Analysis of plastics in recycling by NIR hyperspectral camera KUSTA1.9MSI