With the rapid penetration of industrial automation technology, the long-standing reliance on manual operations in the film casting industry, resulting in low efficiency and poor precision, urgently needs to be addressed. Our team has successfully implemented the "PLC and AC servo motor controlled film casting production line" technology. This intelligent control combination automates the entire process from unloading to receiving, providing a replicable solution for industry transformation. This achievement, through the synergy of core technologies and modular design, has reduced the manual intervention rate in traditional film casting production to less than 10% and improved production accuracy by 40%, garnering widespread attention in the industry.
Core Technology Partnership: PLC "Brain" Linked to Servo "Hands and Feet"
The core competitiveness of this intelligent production line stems from the precise coordination of a programmable logic controller (PLC) and AC servo motors. As the industrial "intelligent brain," the PLC boasts strong anti-interference capabilities and operates stably in dusty and high-frequency vibration factory environments. It performs the core tasks of signal reception, logical operations, and command transmission. The Siemens 1515-2 PN PLC selected for this project supports Ethernet expansion and boasts high computing speed. It can simultaneously process signals from 12 devices, providing the computing power necessary for multi-unit collaboration.
AC servo motors act as the production line's "precision hands and feet," boasting speed and position control accuracy of 0.01 rad, 30% lower operating temperatures than traditional motors, and a 60% reduction in failure rates. The team employed a Siemens S120 series servo system, compatible with a variety of devices, including synchronous and linear motors. Linked to the PLC via the PROFINET high-speed industrial network, signal transmission latency is kept to under 0.1ms, ensuring real-time command execution. "Like the perfect coordination of an athlete's brain and muscles, PLC commands are instantly translated into precise motor movements," explained the project's technical lead.
Six Major Units Create a Closed Loop: A 20-meter Storage Rack Solves the Problem of Material Runouts
The production line utilizes a modular design, with six major functional units forming a complete closed loop from raw material input to finished product output. Each unit embodies ingenious intelligent control. The unwinding unit utilizes a dual-station pneumatic shaft design, adaptable to both 3-inch and 6-inch cores, and capable of carrying a maximum of 800 kg raw material rolls with a diameter of 800 mm. The PLC calculates the roll diameter in real time, automatically alarming when the remaining material is insufficient, improving roll-changing efficiency by 50%. The unwinding, traction, and storage units are crucial for ensuring continuous production. The traction mechanism prevents material slippage by regulating the pressure between steel and rubber rollers. A 20-meter-long storage rack acts as a "material buffer zone." When the unwinding unit changes rolls, the rack automatically refills, completely eliminating the efficiency losses caused by roll breakage during roll changes in traditional production. The servo-powered main traction unit pre-treats the raw materials before they enter the core process. Through three steps of static elimination, web correction, and dust removal, the cleanliness level of the raw materials is elevated to 99.2%, laying the foundation for subsequent coating quality.
The coating unit, a core process, innovatively features a membrane head adjustment mechanism with a dial. Workers can precisely adjust the membrane head height and tilt through a human-machine interface, maintaining a coating thickness tolerance within ±2 microns. The coated raw materials enter the water trough unit for final cleaning. An adjustable wiper at the outlet adjusts the pressure in real time based on the raw material's moisture content, ensuring a stable moisture content in the finished product. The lifting and exhaust units are designed with safety and environmental considerations in mind. Wireless remote-controlled lifting equipment simplifies maintenance operations, and the exhaust system increases volatile gas collection to 95%, meeting the latest environmental standards.
Visual control + data accumulation: Worker training is shortened to 3 days.
The production line's user-friendly design is reflected in comprehensive optimization of the operator interface. The visualization system on the industrial computer integrates eight types of operating interfaces, including an overview screen, frequency conversion parameters, and servo status. Once logged in, workers can intuitively view operating data for each unit, including 16 key indicators such as production speed, tension, and motor temperature. When equipment anomalies occur, an alarm system accurately displays the fault location and cause, reducing maintenance response time from 40 minutes to less than 10 minutes.
This intelligent design significantly reduces the operational barrier to entry. Traditionally, production line workers required 15 days of training before they could begin work. However, with pre-set parameters and one-touch start and stop functions, the new system allows new workers to operate independently after just three days of training. The system automatically stores three months of production data and supports export and analysis. Data traceability allows companies to quickly identify the root causes of quality issues, reducing scrap rates from 8% in traditional production to below 3%. A representative from a film material company using this technology revealed, "Since the production line went live, our daily output has increased from 800 square meters to 1,500 square meters, while labor costs have decreased by 60%."
The industry's demonstrative effect is evident: paving a new path for intelligent discrete manufacturing.
The successful implementation of this production line not only addresses pain points in the cast film industry but also provides valuable experience for the automation transformation of discrete manufacturing. Its "PLC + servo motor + industrial computer" architecture is flexibly adaptable to various industries, including packaging and printing, and the core control logic can be reused without major modifications. Experts from the China Automation Association stated, "This intelligent transformation solution, focused on specific scenarios, offers a 30% higher return on investment than general-purpose production lines, making it particularly suitable for adoption by small and medium-sized manufacturing enterprises."
The team has applied for three utility model patents for this technology. The next step is to optimize the PLC program algorithm to increase motor response speed by another 15%, while also developing mobile monitoring capabilities. With the continuous iteration of technology, the combined application of PLC and AC servo motor is expected to become the core driving force for the traditional manufacturing industry to transition from "manual operation" to "intelligent manufacturing".