December 12th, 2022
One Step Ahead in GLT - Tobacco Webinar
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Discover our last scientific research and publications, to get to know more about TEWS innovations and the high potential of microwave resonance.
In continuous grain drying fluctuations of the moisture content at dryer entrance are still a major problem resulting in under- or over-drying due to uneven moisture distribution at the discharge and, hence, lead to quality and economic losses.
Recently, grain dryer producers increasingly apply direct on-line grain moisture measuring systems to improve dryer control. In the present study results of laboratory measurements of grain moisture content are presented based on the microwave resonator technique.
These measurements carried out with wheat as test material are aimed to develop a new on-line grain moisture measuring system for dryer control.
We present results on a microwave resonance method providing moisture measurements of single tablets and utilizing a calibration based on multiple products (4 in this study). We compare the results against a standard Karl-Fischer titration method and assess the method accuracy, robustness and linearity. The multi-product calibration covers the moisture range of 0.8-8.4% w/w. We demonstrate a method accuracy of 0.16% w/w, and STD repeatability of below 0.05% w/w. Utilization of a product specific calibration increases the accuracy by a factor of 2-5 but for the price of more labor and narrower covered moisture ranges.
The above together with the method practicality and maintenance-free usage provides substantial benefits in terms of time, material and resource savings compared to the standard Karl-Fischer method.
Company: TEWS Elektronik GmbH & Co. KG
Type of unit: Laboratory Moisture Analyzer with
Microwave Resonance Technology
(MW 4300 & MW 4310)
Written by: Gerald Gallitz
With this new measurement technique it is possible to detect contaminated rods in cigarette production. “Contaminated” means that the rod contains foreign bodies like plastic, rubber, wood, whole stems, metals, lumps of glue, residues of coal and additives of the tobacco process, independent of the colour of these foreign bodies. The detection is based on the application of microwaves, which are electromagnetic waves with a wavelength in the range of 10 cm. Because microwaves penetrate the paper of a cigarette easily, this method can be applied at the rod formation in a cigarette making machine, where no further contamination may occur. The different interaction between microwaves and the tobacco rod in absence and presence of foreign bodies allows to apply a microwave sensor, which was designed for the online measurement of the rod density and moisture as a replacement of the conventional nucleonic sensors. During the last years this technique has proven it’s high precision and long-term stability for the on-line weight control. The signals of this microwave sensor can be used for the foreign body detection, because any foreign body in the rod which moves through the measuring zone, changes especially the moisture signal.
Roller compaction is commonly used in the pharmaceutical and nutraceutical industries to increase and narrow the size distribution of a particulate material, making it easier to process. Both the moisture content of the material and the density of the roller compacted ribbon affect the uniformity and physical properties of the resultant granules. Without process analytical technologies, these parameters cannot be determined on-line or in real-time. In this study, the more commonly used near-infrared spectroscopy was compared and contrasted to microwave resonance for the determination of roller compacted ribbons’ envelope density and moisture content. Results indicate that microwave resonance can offer improved accuracy, robustness, and ease-of-use compared to near infrared spectroscopy for these property measurements.
In the scope of 100% in-line quality control and real-time release of pharmaceutical tablets, the authors present a flexible inspection module for in-line tablet analysis with integrated multipoint near-infrared (NIR) spectroscopy and 3D microwave resonance technology (3D MRT). Via an industrial case study on Diclofenac Sodium tablets, the abilities of this versatile process analytical technology (PAT) tool are presented. It is demonstrated that the combination of Diclofenac concentration prediction via NIR spectroscopy and mass prediction via 3D MRT allow to estimate the dosage of each individual tablet. Single sample repetition tests were performed on 5 tablets, measured 10 times on three different days. A high accuracy and precision of prediction was shown, with an average standard deviation below 0.5 mg. The inspection run demonstrated the added value of such inspection and sorting strategies based on the calculated dosage of individual tablets.