Sensores y equipos de laboratorio para el reciclaje y procesamiento de plásticos y el reciclaje de textiles

Seamless color measurement inline, mobile, and in the lab – based on the same measurement principle and the very same technology, using the 0°/45° color measurement system SPECTRO-3-FIO-MSM-ANA-DL in combination with the sensor frontend KL-D-0°/45°-85-…-D-S-A3.0

Increasing use of recycled materials
The increased use of recyclates worldwide is of great importance for several reasons:

• Environmental protection
• Reducing waste
• Circular economy
• Energy saving
• Legal requirements

Achieving perfect color consistency – one of the major goals in modern plastics recycling
The goal of plastics recyclers is to achieve a quality level as close as possible to virgin material. One of the key criteria in this context is color. Detecting color deviations as precisely as possible – ideally inline during the production process – is therefore essential. Accurate inline color measurement of recyclates starts with selecting the right measurement location within the production process. Challenging conditions, such as high material temperatures, moving pellets, and elevated humidity require robust and high-performance sensor technology.

Real-time color control of recyclates – both inline during production and in the lab
To enable a rapid assessment of the recyclate quality with regard to color, the measurement should be carried out immediatelly after pelletiting. The measurement can either be performed directly on the vibrating conveyor or through a sight glass at the silo. In addition, a sample can, of course, be taken from the ongoing production process and subsequently analyzed in the laboratory.

Color measurement of recyclates during production
The color of the recyclate is an important quality criterion, as it can serve as an indicator of possible contamination. Darker or uneven colors may indicate that the recylate has not been completely cleaned or that it consists of different types of plastic. A uniform and appealing color is crucial for many end products. Recyclates that have a uniform color improve the appearance of the end product.

Inline recyclate color measurement in a recycling plant
The first way which the color of recyclates canbe measured is immediately after the extrusion process. The color sensor system is directed at the recyclate flow conveyed on a vibrating chute. Thanks to the robust design of the sensor system, reliable measurements can be made even at high recyclate temperatures, turbulently moving pellets and elevated humidity.

Inline color measurement at the vibratory drying system
The vibratory dryer is located directly downstream of the recyclate pelletizing process. At the rear end of the vibratory conveyor, the pellets are already dry enough to perform inline color measurement. However, it must be taken into account that the material is transported rather turbulantly along the vibratory conveyor and that varying material flow heights have to be expected.
→ KL-D-0°/45°-85-2000-A3.0                   
    + SPECTRO-3-FIO-MSM-ANA-DL
    + SI-PPC-500-15“ (monitoring system)

Inline color measurement system featuring additional sensors for distance control, temperature monitoring, contamination detection, and polymer type identification
An enhanced measurement system that can also be installed at the vibratory dryer is a combination of a color measure-ment system and a polymer type identification system operating in the NIR range.
→ NIRCOL-SYS-85

The compact inline color measurement system COL-SYS-85-CL for the vibrating
The COL-SYS-85-CL system is a simplified inline version designed exclusively for color measurement. Here as well, the pellet stream height required for acurate measurement is defined by means of a flat plate acting as a pellet shield. Calibration is performed directly on the height-regulated pellet stream.
→ COL-SYS-85-CL

Inline color measurement of pellets through a sight glass mounted on a pellet dryer
The color of plastic pellets can be measured inline through a sight glass mounted directly on the pellet dryer. This non-contact measurement approach enables continuous monitoring of the pellet color during the production process without interfering with the material flow.
→ SPECTRO-3-0°/45°-MSM-INLINE-ANA
     + SI-PPC-500-15“

Stabilization of the pellet color by controlling the dosing of additives at the dosing units directly upstream of the extruder
Volumetric dosing units can be controlled relatively easily by external signals (0V to 10V or 4mA to 20mA). An electric motor drives the feeder screw ofthe dosing unit, whereby 0V corresponds to a standstill of the screw and 10V represents the maximum dosing rate.

The closed-loop control system for stabilizing the color of recycled material
A typical recipe for producing recycled material contains information about which masterbatches or additives are used in the respective dosing units and the quantities to be added.

Measurement accuracy and comparability of color values
In many recycling plants, the L*a*b* color value of a recyclate is already measured in the laboratory. The color value measured inline should match the color value determined in the laboratory as closely as possible. In many cases, an injection molding machine is used to produce an injection-molded plate from recycled material taken from production and the color value is then determined.

Display and recording of the color values determined inline
The DOCAL Windows® software is used to display the L*a*b* color values numerically and graphically, as well as their deviation dL*da*db* from the target value. At the same time, the data is stored in a file on the panel PC and the data can also be transmitted via fieldbus (ProfiNet) or Ethernet.

Determining the recyclate color values using a mobile color measurement system
The mobile color measurement system can be used to obtain color measurement data more quickly than in the laboratory, even without an installed color sensor system. A recyclate sample can be taken on site from production and fed into the mobile unit (hopper capacity: 11 liters). The mobile color measurement system is calibrated in the same way as the inline unit.
→ SPECTRO-3-0°/45°-MSM-MOBILE-ANA-P

Determination of the recyclate color values in the laboratory
The L*a*b* color value of a recyclate sample can also be determined with high accuracy (dE < 0.3) using the color laboratory device, without the need to first produce an injection-molded plate from recyclate at great expense.
The high color accuracy is achieved by measuring the recyclate flow and continously averaging the measured values. This eliminates the influence of the random position of the individual granules in the light spot of the measuring device.
→ SPECTRO-3-0°/45°-MSM-LAB-ANA-LF

Calibration using the DOCAL software SPECTRO3-MSM-DOCAL-Scope VX.X
With the aid of the calibration wizard, calibration of the system is designed to be extremely simple. First, the user is prompted to select a suitable RAL card for white balancing purposes (for example RAL 9010).

Compact laboratory system for measuring the color of recyclates
A very compact and inexpensive color measurement system was created using a measuring table top and an optomechanical rail. The recyclate samples are filled into the supplied trays and moved laterally under the light spot in a figure-of-eight movement. This also achieves an accuracy comparable to inline measurement.
→ SPECTRO-3-0°/45°-MST

Color measurement of recyclates in the plastics processing industry
Due to the increasing use of recyclates in the processing industry, it is advisable to carry out an incoming inspection in order to prevent any fluctuations in the quality of the recycled material.
The SPECTRO-T-4-10-DIF-VISNIR enables color verification of the recyclate at various stages throughout the production process:
• At the silo
• At the material feed container
• At the dosing unit
→ SPECTRO-T-4-10-DIF-VISNIR

Recyclate color measurement at the silo
A sight glass is placed at a suitable location on the granulate silo and a suitable color sensor (0°/45° or d/0° method) is then installed. The color values are also evaluated using the DOCAL Windows® software.
→ SPECTRO-T-4-INLINE-VISNIR

Recyclate color testing during material feeding
and dosing
A recyclate color check can also be carried out at the material feed container. The system operator is informed about the color quality of the recyclate used at an early stage. Furthermore, color measure-ment data can be transmitted to the quality assurance department in real time.

One sensor. Three worlds. 
Mobile. Lab. Inline.
SPECTRO-T-4 brings the same proven technology from incoming goods inspection to the laboratory and directly into production. Check pellets immediatelly upon delivery – even inside a big bag. No sampling, no delays, no compromises.

One sensor platform –
Lab, Inline, and Mobile
Measure with the same sensor technology everywhere and compare results with confidence. Whether in the laboratory, directly on the production line, or with a mobile device, you always work with a consistent measurement principle.

All measurement intelligence is
built directly into the sensor
The integrated electronics and firmware handle the entire measurement process, while the panel PC serves as a convenient interface for visualization, monitoring, and data logging.
In addition to delivering precise L*a*b* color values and their deviations (dL*, da*, db*) from a selected reference, the SPECTRO-T-4 simultaneously provides measurement data in the near-infrared N*i*r* space, including the corresponding deviations (dN*, di*, dr*).
(...)
 

Highly accurate detection of color and polymer type for optimized quality assurance
Inspired by nature, we’ve equipped our color sensor systems with NIR technology – now they don’t just see color, they recognize the very identity of plastics.

It’s not just about extending vision from visible to NIR – it’s about taking the same sensor from mobile to lab to inline.With SPECTRO-T-4-MOBILE you can test pellets right after delivery – even in the big bag. Drop the sensor into the granulate, kick off the measurement on the portable PC, and sweep the head in a figure-eight. You’ll hit dE and dNir values down to 0.3, and thanks to the extra battery in the portable unit, the sensor keeps going for hours.
→ SPECTRO-T-4-MOBILE-VISNIR

Same sensor in lab, inline, or mobile – results you can truly compare. Pellets are measured on the fly, always through a sight glass that shields the optics from the stream. A key advantage of measuring pellets in motion is that the random orientation of each pellet in the light spot is effectively averaged out. Over just a few seconds, as the granulate flows from the hopper, this results in a stable mean – achieving a dE and dNir value of 0.3. Just hit the button and let it measure.
→ SPECTRO-T-4-LAB-VISNIR

Inline, the SPECTRO-T-4 sensor system can be mounted to a dosing unit via a sight glass. The measurement data reveals whether the recyclate can be used 1:1 or if virgin material needs to be added to stay within tolerance limits. The sensor data can also be fed directly to the dosing unit to close the control loop. Pellets just delivered? Whether in the silo, day silo, or bag emptying station, recyclate quality can be checked on the spot – with sensor data sent over Ethernet or fieldbus right to QA.
→ SPECTRO-T-4-INLINE-VISNIR

The sensor does it all – electronics and firmware take care of the measurement, the panel PC is just the window for viewing and logging.Alongside the color values L*a*b* and their deviations dL*, da* and db* from a chosen reference, the SPECTRO-T-4 also delivers measurement data in the near-infrared N*i*r* spectrum, including the differences dN*, di* and dr* relative to the set reference. It doesn’t just save L*a*b* and N*i*r* with their reference deviations – the system also logs the raw X,Y,Z values in the visible, plus NIR1, NIR2, and NIR3 in the infrared.

In the shop floor it’s the trend that counts, in QA it’s the limits – and both sides get the data instantly, from production to office.If a reading goes off course, the trend makes it visible early on – a big win for the operator. At the same time, the sensor can push its data over serial links to a master controller, which directs the dosing unit on how to react when tolerances are exceeded. Cross a tolerance limit, and it pops right out: a colored frame in the trend view and a bold background highlight in the delta display.
→ SPECTRO-T-4-10-DIF-VISNIR