Packaging

How load cells and weighing electronics turn containers into scales

Wednesday 18. October 2023 - Open, close. Open, close. Again and again, the small flaps of the containers weighing tons open for a few seconds. Fine quantities of powder quietly trickle into narrow jars. One jar after the other fills up, all at high speed.

System integrators and process vessel manufacturers face ever-increasing demands for precision, efficiency and quality in today’s industrial landscape. The integration of load cells n as an OEM (Original Equipment Manufacturer) solution offers these companies a versatile and powerful way to provide process safety to their customers while optimising their own products and services.
Find out in this article what advantages integrated load cells from Minebea Intec offer in combination with innovative weighing electronics in container weighing for level control as well as in filling and dosing processes.
Open, close. Open, close. Again and again, the small flaps of the containers weighing tons open for a few seconds. Fine quantities of powder quietly trickle into narrow jars. One jar after the other fills up, all at high speed. The atmosphere in the production hall is one of precision and perfection. An employee in a lab coat moves through the aisles, his gaze fixed firmly on the control screen. On it, he can reliably follow the automated filling and dosing proces-ses. The hall is peppered with impressive production facilities and yet it is an inconspicuous element that makes this high-precision production process possible: the load cell in combination with its smart electronics. Hidden under the huge containers is this small but fine technology, which plays a decisive role not only in the production halls of the pharmaceutical industry but they also have a firm place in the food, plastics and cosmetics industries, where precision is just as important in the dosing of ingredients as in the production of medicines. From the filling of fine spices to the pro-duction of food supplements: Load cells are indispensable helpers that ensure the quality of the manufactured products.
The proof: High-precision weighing solution for Pharmatec GmbH
An example from the pharmaceutical industry shows how suc-cessfully Minebea Intec’s weighing technology works. The Synte-gon subsidiary Pharmatec from Dresden, a manufacturer of ultra-pure media systems and process plants, commissioned Minebea Intec with the implementation of six hopper scales. At Pharma-tec’s customer, liquid medicines were to be dosed from tanks with a capacity of several tonnes with gram accuracy and the weighing results recorded reliably and reproducibly. In addition to the pro-cess requirements, the local conditions also posed an extended task for the application and required several visits from Minebea Intec’s specialist personnel for the design planning alone.
Pharmatec benefited here from the sophisticated Minebea Intec technologies: The Novego weighing module offers an integrated, infinitely variable height adjustment of up to 8 cm, allowing diffe-rent installation heights. “The most difficult part of load cell instal-lation is mounting the load cells in the correct position and the associated protection from external forces, such as horizontal forces and the resulting lifting forces,” says Yannick Salzmann, Global Product Manager. “First and foremost, it is about making the system accuracy as high as possible through our installation kits and know-how. In addition, without secure mounting kits, the container can tip or even fall down . In many cases, installation kits also provide overload protection for the load cell.” For Phar-matec, the specialists from Minebea Intec chose the Novego weig-hing module with an integrated installation kit: 360° restraint, anti-lift device and anti-tilt protection eliminate the need for time-consuming constrainer alignments.
Further selection criteria were the weighing module’s special re-sistance to lateral forces and its hygienic design, which is so im-portant for the pharmaceutical industry. In a production plant in the pharmaceutical industry, easy and residue-free cleaning must be guaranteed for maximum sterility. The weighing modules from Minebea Intec are made of stainless steel 1.4418 and therefore have an extremely high corrosion resistance. This makes the weighing modules insensitive to dirt, water and even aggressive cleaning agents.
Fill level under control: load cells are the optimal solution
The second field of application for load cells in container weighing is level control. The choice of the right technology for this applica-tion is crucial, as it has a direct influence on the accuracy and re-liability of the measurements. Compared to other technologies such as ultrasonic and free-radiating radar, load cells offer several key advantages. Firstly, load cells provide very accurate weight and level measurements regardless of the material, which is parti-cularly important in industries with strict quality standards. Se-condly, they are very robust, which leads to a long service life and thus a high level of investment security. Another advantage is that the load cells are mounted below the container, which avoids per-foration of the container and thus significantly improves hygiene.
Link E weight transmitter for quick and easy weight recor-ding
In order to be able to use the weight values efficiently in the pro-duction processes, the signals from the analogue load cells must be determined and passed on to the production control system. These tasks are performed by weighing transmitters. “With the Link E weighing transmitter, Minebea Intec offers simple process integration, intuitive operation and precision at an affordable pri-ce,” says Yannick Salzmann. “This weighing electronics is current-ly the only product on the market that has a high-contrast touch display on which the status and all functions can be read directly.” Using a standard web browser, the Link E can be easily configured by entering the IP address without any additional software instal-lation. “For security, this data is password-protected and can addi-tionally be saved on the PC. The well-known ‘Smart Calibration’ also enables adjustment completely without weights,” says Yan-nick Salzmann. With these functions, installation and access times are reduced to a minimum and mechanical errors are detected.

The Link E weighing transmitter also impresses with its variety of interfaces. No less than nine common interfaces and fieldbuses – including Profibus, ProfiNet or Ethernet/IP – are available for easy integration into automation systems, so that every user worldwi-de can find the right connection for their production processes. For integrators and plant engineers, this has the advantage that they do not have to change manufacturers and familiarise them-selves with other weighing systems. This ensures fast and direct integration into higher-level systems and avoids errors. Three digital inputs and outputs are available for simple control tasks.
Minebea Intec offers a wide portfolio of load cells
Minebea Intec offers a complete range of components for weig-hing a wide variety of container and silo types, from very small process containers to very large outdoor silos. From entry-level products such as the Pancake load cell for container weighing as an alternative to level sensors to premium solutions such as the high-precision Novego weighing module , the company offers different solutions depending on the requirements. However, Mi-nebea Intec not only stands for a broad and high-quality product portfolio in the field of weighing and inspection technologies, but is also a competent partner for its customers throughout the ent-ire planning process: from initial consultation to commissioning and maintenance. This holistic approach ensures that they receive the best possible solution for their individual requirements and can thus increase their efficiency and ensure the quality of their products – be it cosmetics, food or even medicines.