With the rapid development of the food packaging industry, the demand for bags made of materials such as plastic composite films is also increasing. Three-side seal bag making machines (as shown in Figure 1) are used to produce various plastic-plastic and paper-plastic composite materials. They are widely applicable to three-side seal bags made of plastic composite films, aluminum-plastic composite films, and paper-plastic composite films, making them ideal for various center-seal and three-side-seal bags. They are also suitable for manufacturing stand-up pouches, embossed buckle bags, zipper bags, and other irregularly shaped bags.
This system utilizes a Weichuang motion controller + servo bag-making machine system, employing four 1.3KW material pulling servos, one 0.75KW rear feeding frequency converter, and one 4KW main unit frequency converter. The Weichuang high-performance V5 motion controller (hereinafter referred to as V5) serves as the control mechanism, with an HMI for human-machine interaction. The temperature control module uses solid-state relays to control thermocouple heating to achieve the customer's heat-sealing temperature. Normal operating speed can reach 120-150 bags/minute (200mm bag length).
Figure 1: Three-side sealing bag making machine
II. Equipment Structure
The three-side sealing bag making machine mainly consists of the following parts:
The rear feeding mechanism is controlled by a frequency converter and a magnetic powder clutch to control the feeding tension.
The heat sealing mechanism is driven by a frequency converter and moves up and down reciprocatingly. The thermocouple heats the sealing knife to achieve the effect of sealing the bag. It consists of a horizontal seal and a vertical seal. The horizontal seal heats the two sides of the bag, and the vertical seal heats the bottom edge of the bag, which is the so-called three-side seal.
Feeding mechanism: A servo-driven feeding roller achieves the feeding purpose. It ensures that the plastic bag of the set length is fed through the heat-sealing mechanism before it leaves and re-enters the cutting roller. The servo near the cutter operates in two modes: a fixed-length mode, where it stops after a set number of pulses; and a calibration mode, where it searches for the mark at low speed after a set number of pulses, stopping when the color mark photoelectric sensor receives a signal. The other three servos operate synchronously with it.
Cutting mechanism: cuts open the heat-sealed bags;
The structure of the three-side sealing bag making machine is shown in Figure 2 below.
Figure 2: Structure of a three-side sealing bag making machine
III. System Implementation
1. The VEICHI products and hardware configuration used in the system are shown in the following figure (Figure 3).
Figure 3: System Hardware Configuration
2. Solution Implementation:
The high-performance V5-MC104 motion controller from Weichuang is used as the host controller. The output pulses control the position of four material pulling servos. The V5 has a unique 4-axis high-speed output design with a maximum output frequency of 3MHz. The axis ports have separate dedicated connection cables with the SD700 series servos, eliminating the need for external wiring and making installation simple and convenient.
V5 communicates with the inverter via RS485 for speed control, eliminating the need for analog output and saving the need for an analog output module; it also communicates with the HMI RS422 to enable data interaction between the HMI and the controller.
It adopts a dual serial port HMI, with the other serial port communicating with the temperature control module via RS485. This allows for real-time, efficient, and stable temperature control.
IV. System Advantages
1. The whole machine adopts our V5 motion controller, with a dual-CPU hardware architecture for faster underlying processing speed, centralized control via human-machine interface, stable performance, easy operation and maintenance, and the operation interface can be switched between Chinese and English.
2. All parameters are displayed in real time via the human-machine interface, and can be preset with bag making speed, bag making length, temperature, counting, etc.
3. Temperature is PID controlled, adjustable from 0 to 300℃, with contactless automatic control and centralized settings via human-machine interface.
4. Pneumatic multi-functional automatic punching, automatic scraping and collection, equipped with static electricity elimination device.
V. Summary
Weichuang's three-side sealing bag making machine system boasts advantages such as high efficiency, good stability, and strong anti-interference capabilities. Utilizing a complete set of our products provides an overall solution for the three-side sealing system. It is simple to operate, requires minimal parameter adjustments, and is easy to maintain. The system can meet customers' requirements for bag making of different materials and specifications, effectively improving production efficiency and increasing capacity while ensuring the overall stability of the system's performance, thus satisfying customers' comprehensive requirements for bag making systems.
