Page 57 - 《橡塑技术与装备》英文版2026年1月

NEW TECHNOLOGIES AND PRODUCTS

1.1 Digitization and informatization of To equip the unit with information management
equipment capabilities, a digital upgrade of its existing control system is
1.1.1 Equipment introduction required. Without affecting the normal operation of the unit
As shown in Figure 1, it is a photo of the existing CHT- for experiments, hardware devices such as data acquisition
30B/600-11-48 twin-screw extruder in the laboratory. This unit modules, PLC controllers, and communication gateways
consists of a host machine, a feeding system, a cooling water were added to enable the collection, storage, monitoring, and
tank, a dryer, and a granulator. Its control electrical system real-time analysis of core operational data. The operating
adopts a traditional electrical control scheme primarily relying parameters of the unit are shown in Table 1, encompassing two
on relays, which does not meet the basic conditions for device parts: heating and cooling, and motor operation. There are four
information management. categories: current, voltage, switch status, and temperature,
totaling 59 characteristic data points. Among them, real-time
temperature and set temperature are directly collected to the
PLC controller via 485 communication. Motor and heater
current, as well as system voltage, are collected through
4~20 mA analog conversion. The on/off status of the cooling
solenoid valve is indirectly connected to the digital input
port of the PLC via an intermediate relay, using the output
Figure 1 Twin-screw extrusion unit
signal from the temperature controller. All collected data is
aggregated into the PLC controller.
1.1.2 Data and collection methods

Table 1 Unit operation data collection
Data category Data source Collection Method Signal type
Set temperature, actual temperature Machine barrel and head of Zone 11 Temperature sensor Digital quantity
Cooling state Machine barrel in Zone 11 Thermometer output Discrete signal
Main motor, feeding motors, water pump, vacuum pump, dryer,
Current Current transducer 4~20 mA analog quantity
granulator
Main motor, main feeding motor, upper-stage side feeding
Voltage Voltage transmitter 4~20 mA analog quantity
motor, pelletizer
1.1.3 Informatization transmission transmission bandwidth, enabling real-time data visualization
After completing data acquisition, the PLC controller display and sensitive fault warning response. Specifically,
transmits data through both on-site and remote channels. within the laboratory's on-site network environment, data
On the one hand, the data is integrated into the on-site data transfer between the PLC controller and the single-board
management system, enabling real-time monitoring of on-site computer is achieved using the Node-RED open-source IoT
data. On the other hand, the data is uploaded to the server cloud platform. Furthermore, a real-time data visualization system
platform via an intelligent gateway, facilitating data storage has been developed using its control panel tool, as illustrated in
and remote monitoring. Additionally, through the analysis Figure 2.
and processing by a real-time fault analysis application, fault 1.2.2 External network
diagnosis is achieved. The external network primarily serves remote data
1.2 On-site and external network configuration monitoring. Specifically, the intelligent gateway accesses the
1.2.1 On-site network laboratory network environment via Ethernet and provides
The laboratory site is equipped with both wired and external network data services. To ensure stable data collection
wireless network access methods. Since the on-site access and provide necessary redundant network resources, the
devices are within the network range of the same high- gateway can also access the mobile 4G network through
speed router, the on-site equipment enjoys high-speed data cellular network.

Vol.52，2026 ·11·