Feb 1, 2024
In early 2023, Valmet provided for Liansheng's Zhangpu site BM1 coated board and PM3 paper machines. On May 1, the BM1 successfully started up, half a month ahead of schedule. On June 8, PM3 started up smoothly in one go and started production. All the products met the quality inspection on the next day and received positive feedback from the market. In October, the average speed of PM3 already reached 1650 meters/min, with an annual output of 50,100 tons. One month later, it reached 1701 meters/min.
Both BM1 and PM3 are equipped with extensive automation packages from Valmet, including Machine controls (MCS), Quality Controls (QCS), Profilers, Condition Monitoring, Machine Vision and additional Analyzers on PM3. The automation system has proven to be a critical part to monitor and maintain product quality as well as production efficiency.
Efficiency – this is the word mentioned many times by Mr. MingChao Liu, Automation Manager for BM 1.
Extensive Automation Package brings efficiency in all aspects
Valmet DNA Automation System provides a unique single-system approach in the industry and stands out as a user-friendly and easily operable system. A unified platform with built-in MCS, QCS, and Machine Condition Monitoring enables Liansheng Zhangpu’s operators to focus on the most meaningful and manage larger process areas. Valmet DNA simplifies mill automation and eliminates the need for excess hardware and data communication between processes becomes more efficient. The clarity and reliability of the system have enabled efficient project commissioning and reduced startup time.
“If we use three different systems, we will need three operators. Now with MCS, QCS, and Machine condition monitoring under one Valmet DNA frame, only one operator is needed. This is a great saving for manpower, especially in the current situation where paper mills have difficulties recruiting people. Besides, the operation is also more efficient.” Says Mingchao Liu, Automation Manager for BM 1.
Having one unified platform also leads to better reliability and significant savings in spare parts costs. Since all key parts of automation systems are delivered by Valmet, fewer spare parts categories are needed. With optimized inventory and more efficient planning, Liansheng has achieved considerable savings in maintenance costs.
Better end-product quality, higher machine speed, and enhanced efficiency
The BM 1 utilizes Valmet IQ Machine Vision to quickly identify defects and help prevent web breaks using advanced AI. This leads to higher machine speed, improved quality, and enhanced efficiency. Both lines are equipped with Valmet IQ Machine Vision and the results are very satisfactory. “Currently we have 52 cameras in our Web Monitoring System (WMS) that can meet daily needs. We are very happy with the performance so we plan to add more so that we can take faster action when defects occur. The new Web Inspection System (WIS) has shown outstanding results compared to other WIS suppliers. Even blade scratches can be detected. There are very few suppliers who can do this in the market.” Says Mingchao Liu, Automation Manager for BM 1.
By utilizing advanced lighting, ultra-fast cameras, and industry-leading software technologies, the Valmet IQ Web Inspection System can instantly identify defects, even at high production speeds. It also allows BM1 to fast detect the quality issue in the early phase, identifying defects coming from the wire section before sizing. The early detection allows for corrective actions to be taken at a very early stage.
“Another benefit arises when defects information is communicated to winder. We can lower the speed on time to avoid breaks. This also improves our production efficiency.” Says Naicong Wang, Automation Manager for PM3.
Valmet is an industrial leader in quality control solutions. On this machine line, Liansheng relies on IR-based direct coat weight measurement technology, which is superior in accuracy for coated board grades. Contactless caliper measurement provides precise profile information to manage important final quality parameters such as stiffness. Also, compared to traditional contacting caliper measurements, the optical design helps to avoid defects and marking on the premium side of the product. Valmet IQ Quality Management System reliably manages quality and improves process performance by speeding up the grade changes and reaching the on-specification quality after startups and break recoveries.
Early machine fault detection has prevented unplanned shutdowns
At Liansheng Zhangpu, several hidden faults have been identified through Valmet DNA Condition Monitoring. The developing faults could have caused significant shutdowns and thereby preventing potential production time losses and economic impacts is significant. The system generates real-time machine health information for effective planning and scheduling of maintenance operations.
“When a paper machine is running at high speed, it becomes very difficult for operators to detect faults in the press section if the roll is vibrating. However, DNA Condition Monitoring detected this abnormal situation and triggered an alarm to avoid one unplanned shutdown” Says Mingchao Liu, Automation Manager for BM 1.
With increasing competition in the paper industry, a high focus on energy efficiency, and difficulties in recruitment, the path towards optimized and autonomous mills is inevitable. With Valmet’s automation solutions, Liansheng already built a solid foundation and readiness to move toward the future.