Innovation, intelligence and automation increase precision in weighing equipment for chemical processors
Accurate weighing and dosing are critical to the success of any chemical process, because they ensure product quality, safety and resource optimization. Fortunately, innovative technologies, intelligence and automation are helping processors boost accuracy and precision in their weighing operations. Here, industry experts “weigh” in on the benefits of these developments.
“Whether used in food, pharmaceuticals, chemicals or other industries, accurate ingredient weighing is a critical component in assuring product quality, consistency and safety,” says Joe Schobel, sales engineer for chemicals with AZO (Memphis, Tenn.; azo-inc.com). “Each ingredient’s proportion within a mixture contributes to the product’s finished quality, so any deviation can offset the delicate balance of a precise formulation.”
Keith Melton, sales manager for the battery industry with Coperion K-Tron (Niederlenz, Switzerland; coperion.com), agrees: “High feeding accuracy is of paramount importance in a range of chemical manufacturing applications, including production of battery active materials and pharmaceutical manufacturing.
“First, it ensures the consistency and quality of the final product by maintaining precise proportions of the various chemical components. This is crucial, as even slight deviations can lead to significant changes in product properties,” Melton continues. “Second, it enhances efficiency by minimizing waste of raw materials, thus reducing production costs. Additionally, high feeding accuracy is vital for safety reasons, as incorrect proportions can lead to hazardous reactions or the production of harmful byproducts. Therefore, accurate weighing and feeding systems are indispensable in chemical production applications for ensuring product quality, cost effectiveness and safety.”
Addressing weighing challenges
There are a variety of challenges and needs when trying to provide high-accuracy weighing performance in the chemical process industries (CPI). Vibrations are one of the greatest challenges, while precision in minor and micro dosing, development of new technologies for emerging battery applications and more modernized laboratory weighing equipment are also on the list of demands, according to the experts. As a result, weighing technology providers are working on equipment innovations and enhanced intelligence and automation designed to help minimize challenges and fulfill the requirements of weighing technologies for chemical processes.
Managing vibration. “Environmental factors, such as vibrations from nearby operating equipment, can impact the ability of the weighing system to provide an accurate weight signal,” says Coperion’s Melton. “Recognizing that the weighing system must be able to understand the difference between environmental influences and the actual weight to be measured has led to the development of a number of solutions that address these issues.”
To help the feeder control discriminate between actual weight data and the contaminating effects of inertial forces resulting from ambient vibration, the Coperion Smart Force Transducer (SFT) weighing technology (Figure 1) and KCM feeder control modules were developed. “The SFT weighing technology ensures precise and accurate measurements, which are crucial for maintaining optimal productivity and reducing waste,” says Melton. “At the same time, our KCM feeder control modules play a pivotal role in controlling and managing the feedrate. Together, these two components ensure our systems operate efficiently and effectively, delivering high-quality results consistently, even in difficult plant environments.”
FIGURE 1. Coperion K-Tron’s Smart Force Transducer (SFT) technology delivers high-precision weighing, even in difficult plant environments
Also addressing vibration in weight-based control of highly integrated and stand-alone applications is Hardy Process Solution’s 6850 weight controller (Figure 2). “It’s the first weighing instrument of its kind featuring dual core processing,” says Tim Norman, senior product development manager with Hardy Process Solutions (San Diego, Calif.; hardysolutions.com). “It was designed this way so one core can be used to run an application, such as dispensing or filling, and the other core is dedicated to digital signal processing, to eliminate the effects of mechanical vibrations on a scale system. This is important because vibrations contribute to inaccuracies, therefore eliminating vibration improves not only the process, but product quality, as well.”
FIGURE 2. Hardy’s 6850 series weight controllers are suitable for a variety of weight-based applications. The weight controller features a dual-core processor and combines direct process control with fast, accurate and stable weight data, which is essential to profitable manufacturing operations
Higher accuracy in smaller doses. Because inaccuracy in micro and macro weighments can have a significant influence on reactions or alter a product, there has been a demand for more accuracy in these measurements, says AZO’s Schobel. Fortunately, innovation and automation can provide solutions for these applications. AZO’s Componenter (Figure 3) batching equipment offers a highly accurate, automated dosing and weighing system for minor and macro ingredients. Raw materials are fed into the top of the Componenter system and stored. The middle of the system is where the metering, dosing and weighing of ingredients takes place and the bottom of the system is where ingredients are fed into the next processing step.
FIGURE 3. AZO’s Componenter batching equipment offers a highly accurate, automated dosing and weighing system for minor and macro ingredients
“Whether you produce food, pharmaceuticals, chemicals or plastics, this batching equipment can automate the process, which helps eliminate errors and inaccuracies associated with manual operations, reduces the risk of contamination in the process and simultaneously weighs and discharges ingredients with high accuracy for faster throughput,” says Schobel.
Also recognizing a similar need for precision weighing of small components, especially in the rubber and tire industries, Zeppelin Systems (Friedrichshafen, Germany; zeppelin-systems.com) offers the Automated Small Components Weighing System (ASCW) for fully automated weighing of granular or powdery bulk materials with different densities and flow characteristics and for providing mixtures of bulk materials, which are required in rubber blends.
“The ASCW is available with up to 40 different material hoppers mounted in a row, and is suitable for big-bag and bag feeding,” explains Nicole Werner, product and technology manager with Zeppelin Systems. “Equipped with a double dosing screw with a shut-off valve or vibrating chute with a catch gate and GiW [gain-in-weight] scales integrated in a surrounding roll conveyor, the roll conveyors move multiple batch-collecting buckets prepared with bag inlays along the row of material hoppers. The buckets stop below the material hoppers, are lifted and then balanced by the corresponding scale below. All materials get dosed and weighed into the buckets at the same time until the set values are reached. The clocked dosing will repeat until the first bucket reaches the ejection position, where a bag inlay is removed and the bucket moves onto the bag insertion to start a new dosing cycle.
“Optional features, such as automated bag insertion, bag sealing, labeling and bag handling, are available to fully automate the dosing and weighing process of up to 25-kg batches with a capacity of up to 2,400 batches per day,” she says.
Developments for emerging applications. Battery production is a fast-growing sector, however, the production of battery cathode material is a lengthy and complex process and any fluctuations along the process chain can result in problems, such as subpar end-product quality, plant downtime and wasted material, says Coperion’s Melton. “One parameter that can be controlled is the addition of ingredients. To ensure a steady flow of material, high feeding accuracy is essential or, at the least, high measurability of the added ingredients is desirable.
“The focus is usually less on weighing accuracy and more on the accuracy of the delivered sample, often expressed in terms of two-sigma accuracy,” Melton explains. “For continuous processing, this becomes even more complex, with two-sigma based on a typical sample time of 30 to 60 seconds and increasingly moving towards shorter 5- to 10-second sample times. Naturally, achieving higher accuracies becomes more challenging with shorter sample times, making consistent short-term accuracy of the weighing system crucial.”
On the feeder side, the battery industry has a specific need for dry coating applications. “Accuracy is a crucial factor in this continuous process, because a consistent, thin layer must be applied to achieve the desired result. Dry coating requires a continuous distribution at the outlet, such that the entire width of a calender roll holds the same amount of material. The accuracy is measured across 20- to 50-mm increments, based on the two-sigma/time model, and presents a significant challenge not only for the weighing system but also for the mechanical device,” says Melton. “Coperion has developed a completely new type of feeder to answer this need. Called the Coperion K-Tron Roller Feeder, it will be launched in the new year.”
Similarly, Zeppelin Systems is developing sustainable and digitalized machinery for battery production with a focus on a feeding and dosing unit that ensures a constant and evenly distributed feed of premixed and conditioned dry battery mass to the calender, says Werner.
For dry battery production of battery electrodes, the pre-treated anode or cathode bulk material mixtures must be transferred into the inlet of a calender, she explains. In general, a calender consists of several rotating cylindrical rollers that press the bulk material into a thin film, which is then laminated onto a metal foil to subsequently create the battery electrode. Normally, the flow behavior of the solid mixtures is rather poor. The finished electrode material is difficult to handle due to the binder content and smaller particle diameter. The electrode materials are very sensitive, so even minimal external forces, pressure and increased temperatures may cause the materials to compact into pasty lumps. Because of this, no standard solutions for storage and feeding to the calender can be used.
“However, with the newly developed Feeding & Dosing Unit (FDU) (Figure 4), Zeppelin Systems has solved a challenging task by developing a system that ensures a constant and evenly distributed material flow to the calender,” says Werner. “Thanks to a special design and constant level control, the unit provides a fully automated solution to connect to upstream processes and to allow material storage without risk for bridging.”
FIGURE 4. With the Feeding & Dosing Unit, Zeppelin Systems has developed an automated system that ensures a constant and evenly distributed material flow to the calender to enhance battery production
Modern laboratory weighing
Modern weighing technologies are also evolving to address the growing complexity and demands of CPI laboratories, according to Lucas Foerster, product manager, laboratory weighing applications, with Sartorius AG (Göttingen, Germany; sartorius.com). “Several advancements stand out for their ability to overcome challenges and satisfy user needs.”
Among them are sensor and software innovations. “New lab balances are equipped with advanced sensors and software to monitor ambient conditions, such as temperature, humidity and air pressure, that can affect weighing accuracy,” says Foerster. “These systems either compensate for adverse effects or alert users when conditions might compromise results, ensuring reliable performance, even in suboptimal lab environments.”
Modern weighing technologies, such as those found in the Sartorius Premium Lab Balance Cubis II Portfolio (Figure 5), enhance both product quality and laboratory productivity by providing faster and more stable measurements and reducing inaccuracies, even in challenging conditions. And, the seamless software integration and guided protocols allow laboratories to streamline workflows, maintain efficiency and focus on critical analysis.
FIGURE 5. The Sartorius Premium Lab Balance Cubis II Portfolio enhances both product quality and lab productivity by providing faster and more stable measurements and reducing inaccuracies, even in challenging laboratory conditions
“Further, product quality can be significantly enhanced by using balances that comply with 21 CFR Part 11 requirements. These balances feature robust capabilities, such as user management, electronic signatures, alibi memory for secure storage of every weighing value and comprehensive audit trails,” says Foerster. “These functions ensure data integrity by safeguarding all generated data against manipulation, ultimately supporting high product quality and regulatory compliance.”
Innovation and automation
While every weighing operation differs based on the product being produced and the process environment, modern weighing, feeding and dosing systems that include innovative technologies and automation to enhance accuracy provide significant benefits to weighing applications.
Precise weighing delivers accurate ingredient proportions, which ensures consistency and quality. Automation removes the element of human error from the process and eliminates quality variations due to inconsistent ingredient ratios. “In addition,” says Hardy’s Norman, “Today’s equipment can include advanced diagnostics. When the ability to predict that a scale might need to be calibrated or checked for issues is combined with advances in edge computing and smarter algorithms, users can monitor scale conditions for trouble before issues become critical and adversely affect the process.”
Modernization and automation also boost efficiency and speed up the production process in several ways. Automation allows processes to run 24/7, if needed, and production never has to stop due to lack of ingredients. In addition, modern equipment offers faster response times to changes in weight, says Hardy’s Norman. “The scales of yesterday would update a weight measurement every second or so, but today we are able to read signals from sensors at 4,800 signals per second. This means the weight data sent to control systems can be used to make real-time decisions, such as opening or closing a valve in a process, at precisely the right time. This leads to increased efficiency, as well as better product consistency, less waste and ultimately higher product quality.”
System optimization is also possible with advanced intelligence options. “Controllers are now able to ‘learn’ from the data that is collected during operation of the system and apply this to improve the process,” explains Coperion’s Melton. “One challenging aspect of this involves determining how to use accurate weighing data effectively. This requires not only real-time monitoring but also the integration of past experience values, making a controller truly intelligent. While we haven’t yet incorporated AI [artificial intelligence] into feeding, we offer a variety of smart features.”
Melton says controllers are programmed to manage not only general control and process performance, but also to manage unexpected events, thereby preventing disturbances from causing weighing errors and subsequent poor quality in the final product.
Higher levels of accuracy presented by automation are also minimizing waste in the industry. “More accurate weighing involves not just controlling, but also precisely measuring process parameters. It’s also important to eliminate environmental influences that could affect the accuracy of these measurements,” says Melton. “By doing so, waste can be significantly reduced, leading to more efficient operations, lower costs and higher productivity.”
Production flexibility is also enhanced with modern automated systems. As they are adaptable to diverse production needs, automated weighing systems can accommodate changes in batch sizes and material variations. Flexibility is critical in new product formulations or in environments where fluctuations in material characteristics due to humidity or clumping during storage occur, say the experts at AZO.
Joy LePree