Research and trial production by the National Research Institute of Mechanical Engineering show that automating production lines helps enterprises optimize production costs.

Requirements from practice

Given the risk factors and dangers from chemicals directly affecting people and the working environment, a requirement has been set to automate production lines, particularly in the production of laundry detergent and cleaning agents. This helps enterprises reduce dependence on labor, increase productivity and ensure safety during cargo handling.

With this objective, a group of scientists from the National Research Institute of Mechanical Engineering (Ministry of Industry and Trade) invested in cooperation and resources to gradually master the calculation, design, and integration of automation systems for units under the Vietnam Chemical Industry Group.

Image of large weighing station (inside) and small weighing station (outside) in operation (Photo: Narime)

Through this, the National Research Institute of Mechanical Engineering designed, manufactured, and integrated an automation system using robots (in the packaging and palletizing stages) for LIX Detergent Joint Stock Company, contributing to the completion of the automated production line of this unit.

Accordingly, the detergent production process goes through three stages: detergent processing, detergent packaging, and palletizing & transportation.

Currently, in detergent manufacturing enterprises, the detergent processing stage is already carried out with automatic equipment, with humans playing a role in setting parameters, operating, and monitoring the system.

For the bag packaging stage, in practice, detergent is transferred to the bag packaging stage in various weights. Product dosing for packaging relies on a dosing weighing system. This stage requires high accuracy, directly affecting the efficiency and production costs of the enterprise. With traditional manual methods such as non-automatic scales or automatic scales with old technology, errors in detergent packaging weight are often large and output productivity is very low, resulting in high labor costs and difficulty meeting expansion needs.

As for the palletizing and transportation stage, cartons containing detergent bags are palletized onto pallets for convenient transport and storage. In detergent manufacturing enterprises, the number of product types and weight ranges of products are often very diverse, so the packaging cartons come in many different sizes along with different palletizing specifications. Currently, most of these units use manual labor for palletizing work, which affects palletizing productivity and quality.

Proposing solutions for production line automation

Dr. Phan Dang Phong – Director of the National Research Institute of Mechanical Engineering and Head of the Research Group, stated: As analyzed above, at the detergent packaging stage and the palletizing and transportation stage, most current systems do not meet enterprise requirements in terms of accuracy, quality, productivity, and human resources. These systems have high scientific content and high applicability in manufacturing plants in Vietnam. Therefore, the National Research Institute of Mechanical Engineering (NARIME) has conducted research, calculation, design, and manufacturing of automation solutions including dosing weighing systems and automatic palletizing robots.

Specifically, in the packaging stage, the dosing weighing system will be responsible for controlling the weight of detergent placed into bags per product type. The product dosing weighing system includes mechanical structure, load cells, pneumatic assembly, motors, and a control electrical cabinet directly connected to existing equipment at the plant.

Because the system operates in a chemical environment with corrosive and destructive properties, to ensure durability and long-term stability, all proposed solutions use equipment and scales made of stainless steel (SUS 304, SUS 316). PVC conveyor belts are abrasion-resistant, chemical-resistant, and especially flexible to increase accuracy when weighing small quantities.

Automatic palletizing robot system at LIX plant (Photo: Narime)

Detergent is discharged into the supply hopper assembly and 03 conveyor belts. To ensure productivity and weighing accuracy, the feed conveyor belt will be programmed (with inverter control, servo motor) at multiple speed levels (fast feed, slow feed). The initial discharge into the dosing hopper will be fast – rough weighing (high-speed conveyor), then the conveyor speed is reduced – fine weighing (low conveyor speed). For each product type (bag weight), the conveyor speed will be set and programmed accordingly.

In the palletizing and transportation stage, to completely replace humans, the group of scientists proposed a solution using an automatic palletizing system integrated with a robotic arm. The use of robots brings flexibility to the automatic palletizing system with an increasingly diverse range of product types. A robotic arm can be programmed to handle packages of different sizes or arrange them onto pallets in various ways without requiring changes to the pre-existing design.

The palletizing robot system will fully automate the palletizing and pallet transportation process, including the following main components: Industrial robot arm: performs the task of stacking cartons according to a predefined pattern; the programming of the robot will be done by the project team itself; Pallet dispenser, stretch wrapper, label applicator; conveyor system for transporting cartons, empty pallets, and loaded pallets. Additionally, the palletizing robot system also includes other components such as: electrical-automation equipment system (sensors, pneumatics, etc.), electrical cabinet, and safety fencing.

Opportunity for localization of industrial automation systems

Accordingly, scientists from the National Research Institute of Mechanical Engineering have successfully researched, manufactured, and integrated an automation system using robots for the production line at LIX Detergent Joint Stock Company.

Specifically, the dosing weighing system includes weighing stations designed and manufactured to work with different packaging weights of detergent bags: small weighing stations for sizes 100-1500 grams, large weighing stations for sizes 2-7 kilograms, ensuring a powder dosing error of 0.5% to 0.7%. Additionally, the packaging speed for detergent bags reaches up to 65 bags/minute (for 350g bags), requiring mechanical mechanisms and electrical equipment to operate sequentially and continuously at high speed.

“This is considered a challenge for the Institute’s team of engineers during the calculation, design, and equipment selection for the system.” Dr. Phan Dang Phong said, “Currently, the dosing weighing system has been connected to other systems on the plant’s detergent production line, operating continuously during shifts with a productivity of 3 tons/hour for each small weighing station and 10 tons/hour for each large weighing station.”

For the palletizing and transportation process at LIX Detergent Joint Stock Company, many difficulties arose compared to conventional automatic palletizing systems, such as: limited working space, production line productivity, and carton stacking specifications. These challenges directly affected the system design process.

To address these difficulties, Dr. Phong shared: “The space around the system has been optimally renovated to ensure stable robot operation and save floor space. The arrangement of the carton feeding conveyors has also been cleverly organized to reduce the load on the robots. The gripper mechanism and robot program have also been designed by the Institute’s engineers to suit various stacking specifications at the plant.”

To date, the automatic palletizing robot system at LIX Detergent Joint Stock Company is operating to serve carton stacking onto pallets, palletizing, and transportation for 8 production machines at the plant, with up to 6 different product stacking patterns simultaneously and a machine speed of up to 15 cartons/minute. Monitoring shows that the average daily output of the automatic palletizing robot system is about 500 tons/day, operating continuously for 24 hours.

Dr. Phong affirmed that they successfully researched, designed, manufactured, integrated, and officially put into operation the automation system using robots in the two stages of packaging and palletizing at LIX Detergent Joint Stock Company. Since December 2023, the system has been operating stably, meeting production requirements and is highly appreciated by the user unit.

Designing, manufacturing, and putting into operation automation systems in production is an urgent requirement, on the one hand to serve production needs and save foreign currency, on the other hand to contribute to the development of the domestic industrial automation system manufacturing industry. The successful operation of the automation system using robots for the detergent production line at LIX Detergent Joint Stock Company has contributed to affirming the success in localizing industrial automation systems, serving as a basis for expanding implementation and application to other manufacturing industries in Vietnam.

Source: Cong Thuong Newspaper