The New Techpap NIR spectroscopy for Recycled Paper Bales Inspection Speaker: Didier Rech (Techpap) Authors: -Alain Cochaux (CTP – France) -Pascal Borel (CTP – France) -Guy Eymin Petot Tourtollet (CTP – France) - Didier Rech (Techpap)
Content of the presentation • General presentation of topic : problems & solutions proposed • NIR spectroscopy • First trials in laboratory with NIR spectroscopy • Our industrial “recovered paper bales quality control” sensors • First industrial trials in a mill : procedures & results obtained • Last industrial trials ... completed ! 2 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
1.1 Problem: recovered paper bales quality control • Increasing necessity for papermakers to control, at delivery, recovered paper bales to ensure raw material quality & to pay the “right price” • Crucial interest for papermakers: • Measurement of moisture • Detection of possible presence of unusable materials (metals, plastics, etc) • Distinction of different raw materials (paper / board) for coherence with EN643 standard (1.04, 1.05 …) 3 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
1.2 Current control procedures used • Generally speaking, they are : • Manually made • Very long and tiresome for operators � example : core sampling & traditional measurement of moisture • Limited objectivity � example : visual and/or manual controls • Consequence : Low efficiency � so papermakers certainly “lose money” … 4 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
1.3 Solution proposed • The objective of MONITOR project is to develop an easy- to-use sensor: • Direct, rapid, objective, reliable, low cost • To control in recovered paper bales at delivery: � Moisture � Unusable materials � Grades • To do that, we have developed a sensor based on a new approach : Core-drilling device & Near Infra-Red (NIR) Spectroscopy 5 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
2. NIR spectroscopy (in a few words …) • Already used since several years in different sectors (food processing, chemicals, drugs …) to study the composition of samples (in particular: moisture measurement) • Papermaking sector: « emerging » and « promising » technology for the future • Main advantages: • powerful technique to precisely study samples composition • no need of sample preparation • low price • very rapid (~ 50 ms / spectrum) � ~ 200 measurements in only 10 seconds 6 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
2. NIR spectroscopy (in a few pictures …) Light source with 800nm < λ < 2500nm Reflected photons NIR Spectrometer Sample to study Black Box Composition of Black Box sample Black Box = Multi-Linear statistics models (for predictions) obtained by “calibration / learning” 7 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
3. First trials in laboratory with NIR spectroscopy • Development of a “lab prototype” to simulate the behaviour of a coring device used with our NIR equipment: Fibre with measurement head Displacement of Measurement window sample 8 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
3.2 Moisture measurement • Samples (cores) were made with different moisture contents • For each core, we have done: • Acquisitions of NIR spectrum (= inlet data X) • An accurate traditional measurement of moisture: weighing, complete oven drying, re-weighing (= outlet data Y) 9 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
20 % � Two « λ bands » seem 18 % interesting (around 1440 and 1940 nm) 13 % 12 % � Dynamic more important 10 % around 1940 nm 8 % 7 % • Using statistical methods, several moisture prediction models were built and tested : Δ = « accuracy » of the prediction model = ± 0.35 % 10 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
3.3 Unusable & raw materials measurements Same “procedure” as for moisture : making of cores with different compounds, building of prediction models ( = calibration) & tests • Choice of the different compounds to take into account � Aluminium (metals), 3 kinds of plastics (types:PP, PE, PET), paper and corrugated board • Acquisitions of core spectra with 100% of each compound (for calibration) • Acquisitions of core spectra with blends of several compounds (for tests) � 8 “blends cores” were made with random % 11 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
� Using this « λ band », the system is able to distinguish the different compounds 1700 nm < λ < 2150 nm Plastics Water / Papers Papers 12 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
Conclusion of these first laboratory studies The first results obtained in lab with the NIR spectroscopy have allowed us to check the use and the discriminant capability of this approach for moisture and unusable materials that we would like to characterize (metals, plastics) vs raw materials (paper, board) Manufacture of an industrial prototype 13 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
4. Our industrial sensor for “recovered paper bales quality control” • Two versions of the sensor have been developed: • An “embedded” version : to instrument an industrial coring device, in order to perform direct control at delivery on trucks. This sensor was made to be fixed directly on the output pipe of any coring device. • A “transportable” version : less precise and efficient than the first one, but also much less expensive (no need of a coring device). This sensor is hand-held and it has to be introduced in a hole done with a “simple” drill. 14 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
4.1 Our monitor sensor: “embedded” version screen control buttons control buttons optical fiber / power wire measurement Synopsis of our head complete sensor: PC Spectrometer Light source power coring device Industrial rack 15 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
Some details about the measurement head … pipe with optical fibre measurement reflected signal NIR light & power wire head collection source • The head is very light and very rigid • Total length of the head = 20 cm • Inside the head : optical device to optimize the light illumination & the signal collection in the optical fibre 16 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
4.2 Our MONITOR sensor: “transportable” version • All the acquisition and data processing device is the same as for the embedded version, except for the measurement head which is longer (1m), to be introduced directly in a hole done with any perforating device 17 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
5. First industrial trials in a mill: procedures & results obtained • We have used an industrial coring device with our MONITOR sensors for industrial trials programs • Trials have been carried out on ~ 70 bales (= ~ 150 cores), and for each bale core: • NIR spectra acquisition • Recording of the corresponding outlet data wanted Black Box Moisture spectra % of unusable / raw materials Black Box Black Box EN643 classification (1.04 / 1.05) 18 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
5.1 Results obtained: Moisture prediction « accuracy » of the prediction model = ± 0.75 % 19 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
5.2 Results obtained: Unusable materials prediction • For metals prediction : we can’t conclude with the data obtainable (because only 5 values are not 0 % and the max. value is “only” 0.5 %) • For plastics prediction : « accuracy » of the prediction model = ± 0.45 % 20 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
6. Last industrial trials performed • After the first encouraging trials in a mill, different adaptations (mechanic, hardware, software interface) were done on our prototype to fit it to an autonomous and continuous use in mill by operators 21 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
6. Last industrial trials performed • A new trials program (still in progress) has started for a long duration period with one of our industrial partners • These trials have allowed us to identify and to correct some adverse industrial conditions relevant to the industry (clogging, mechanical constraints, …) • Now, the sensor seems to work well, and we are beginning to obtain interesting results … 22 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
6. Last industrial trials performed (still in progress) : a few results … Moisture prediction « accuracy » of the model = ± 1 % Plastics prediction « accuracy » of the model = ± 0.5 % 23 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
the “recovered paper bales quality control” sensor • 2 versions available : • Easy-to-use • Direct • Rapid • Objective • Reliable • Short pay-back 24 8 th Research Forum on Recycling, Niagara Falls , septembre 2007
Recommend
More recommend
