the Intelligent-control Coating System for Composites Rollers
Tianjin University Tianjin, China email@example.com
Abstract—The paper describes an Intelligent-control
Coating System for resin rollers. The system is divided into five subsystems, the Host-computer Control System, the Slave-computer Control System, the Quantitative Coating System, and so on. The host-computer Control System collects PLC signals, vacuum signals and temperature signals through MCGS, and completes real-time monitoring. PLC is the main unit of the Slave-computer Control System, and it controls servo-motors and metering pumps of the Quantitative Coating System. And an arbitrary proportion of raw materials can be achieved. The system combines PLC, MCGS and servo motors. It runs steadily and even replacing raw materials is very easy. It provides a convenient for diversification of rollers production and is a highly cost-effective control system. It has also achieved satisfactory operating results in tests and in practical applications. Keywords- composites roller; coating system; intelligent-control system; quantitative coating; MCGS
Figure 2. The vacuum polyurethane coating machine.
Wang Hongmei, Hu Ming
Tianbo Science & Technology Co. Ltd. Tianjin, China firstname.lastname@example.org
Rollers, as one of the key components of the printing machine, play a very important role. It directly affects printing quality and product grade. Rollers made of composite materials have significant advantages compared with ones made of traditional stainless-steel materials and polyurethane materials in mechanical properties and oil resistance. Its making method is the vacuum polyurethane coating technology, different with traditional manual coating and machine coating. The vacuum polyurethane coating machine is shown in Figure 1 and Figure 2.
It requires that devices stir, degas, mix on-line and coat in according to the set proportion continuously for 38 hours of work. The whole process achieves continuously allautomatic intelligent operation. Its features are as following: a. Pre-processing and processing of composite materials are done under totally-enclosed conditions. b. Synchronous metering-pump system can achieve the proportion adjustment from 100:10 to 100:40, metering accuracy ≤0.5%. c. Dynamic mixing system adopts online mixing technology, and the two components are homogeneously mixed in mixer. Once stilling more than five minutes, the mixed material may react. d. All-automatic continuously work for more than 38 hours.
Figure 1. The worksite manufacturing composites rollers.
The coating amount is adjusted by moving distance of the metering plungers. They are controlled by high-precision servo motors. Coating process is as following: A cylinder and B cylinder of metering pump respectively measure resin A and harder B according to certain weight ratio. As the plungers driven by metering system go down, resin A and harder B are respectively inpressed into the mixer. The two components are fully mixed. The mixture flows into vacuum chamber and coated through the spray nozzle.
Figure 4. The structure of the intelligent-control coating system.
An arbitrarily adjustable proportion of raw materials is the main feature of the Intelligent-control Coating System. This performance is mainly implemented by the PLC, MCGS and the Quantitative Coating System. Its principle is as following:
1. Vacuum pump 4. Stirring Chamber B 7. Mixer 10. Pressure Valve 13. Outlet Valve 16. Delivery Pump 19. Water Pump 2. Stirring Chamber A1 5. Motor 8. Filter 11. Release Valve 14. Cleaning Chamber 17. Position Sensor 3. Stirring Chamber A2 6. Air Compressor 9. Inlet Valve 12. Vacuum Valve 15. Manual Valve 18. Cleaning Valve
Figure 3. Working principle of the coating system.
We make two same specifications metering pumps, each with a servo system which drives plunger of metering pump. As the speed of servo motors can be set arbitrarily, servo motors run the same time and metering pumps will discharge materials according to the set proportion as long as the speed of servo motors is set in accordance with coating proportion. Coating proportion is set in user interface of MCGS. And servo motors are controlled by PLC. A. Introduction of MCGS MCGS, which is based on a Windows platform, is the configuration software for rapid construction and generation of PC monitoring system. It provides the intact scheme to solve practical engineering problems from data collected to the data processing, alarm processing, process control, animation display and report output. It makes full use of the advantage of the Windows, such as the complete graphics, good interfaceconsistency and easy to learn and easy to use. Its universality is better than previously industrial control systems developed with a special-purpose machine, and it has more extensive application in the field of automation. 1) User Interface of MCGS In user interface of MCGS, all of parameters, such as the proportion of raw materials, density, coating volume and so on, are set. The user interface of MCGS is shown in Figure 5.
DESIGN OF CONTROL SYSTEM
Generally, the traditional coating system adopts logic circuit. And its function is very simple, for example using onecomponent materials and nonadjustable proportion for composite materials. These disadvantages, to a great extent, limit printing quality and product grade, and make it difficult to meet the diversified demands of today's market. For more than ten years, Tianbo company has been working for the development of high-end coating technology, and eventually developed an intelligent-control coating machine, which use composite materials as coating materials and adjust the proportion of composite materials. This is the breakthrough of coating technology. The structure of this Intelligent-control Coating System is shown in Figure 4. The system is composed of the Hostcomputer Control System, the Slave-computer Control System, the Intelligent Temperature Control System, the Vacuum Control System and the Quantitative Coating System. The Host-computer Control System collects PLC signals, vacuum signals and temperature signals through MCGS (Monitor and Control Generate System), and completes real-time monitoring. At the same time, the Host-computer Control System sends commands to the Slave-computer Control System, the Intelligent Temperature Control System and the Vacuum Control System and controls them running in accordance with established requirements. PLC is the main unit of the Slavecomputer Control System, and it controls the Quantitative Coating System, which is composed of two servo-motors and two metering pumps. The servo-motors controlled by PLC drive the plungers of metering pumps moving, and an arbitrary proportion of raw materials can be achieved.
Figure 5. User interface of MCGS.
A Motor Downgoing Signal
B Motor Downgoing Signal
A Motor Upgoing Signal
B Motor Upgoing Signal
A1 Vacuum Signal
A2 Vacuum Signal
A2 Owing Signal
B Vacuum Signal
A1 Owing Signal
A Outflow Valve
B Outflow Valve
A Initial Position
B Initial Position
B Owing Signal
A End Position
B End Position
M * 60 *1000 ? Td ? Tb Ve GA *M *d A G A + GB = 1.59 * Te 2.25 * D A * G B *VeA * D B GA L + VeA * Te Tb L + VeB * Te1 Tb
A1 Vacuuming Valve
A Motor Running/Pusle Signal 1+
B Motor Running/Pusle Signal 2+
B Motor Direction/Pusle Signal 2+ A1 Pump
B Vacuuming Valve
B Outflow Valve
A Motor Direction/Pusle Signal 1+
Dynamically Stirring Motor
Alarm LED and Bubber
A2 Vacuuming Valve
A1 Stirring Motor
A2 Stirring Motor
B Stirring Motor
A Outflow Valve
VeA VeB =
(2) (3) (4) (5)
Figure 6. Connecting diagram of PLC.
V Ab = VBb =
In formulas, Te : Coating Time, M: Coating Amount, Ve : Coating Velocity, D A : Density of Resin A, DB : Density of Harder B, Td : Delay Time, Tb : Back Time, VeA : Coating Velocity of Resin A, VeB : Coating Velocity of Harder B, GA : Weight Ratio of Resin A, GB : Weight Ratio of Harder B, VAb : Back Velocity of Resin A, VBb : Back Velocity of Harder B, L : Distance between Initial Position and End Position.
3) Perfect Security The user can set the operating authorities of menus, buttons, and so on. It allows privileges operators to operate certain functions and avoid unrelated persons to misuse. For example, weight ratio of Resin A in casting program is set only by administrator. B. the Slave-computer Control System PLC is a special device designed for digital computing applied in industrial environment. It can implement all kinds of operation orders, such as logic instructions, ordering instructions, timing instructions, counting instructions and arithmetic instructions in its internal memories. It can input or output digital/analog signals to control various types of mechanical movement and production processes.
The input contacts of PLC are switching signals and connect with control switches and sensor signals. The former 8 bits of its output contacts are multiplexed signals (switching signals or pulse signals) and connect with servo motors. Other output contacts are switching signals and connect with relays. Supplemented by PLC program, you can achieve the switches controlling peripheral devices, such as servo motors, through PLC and controls the whole equipments running in accordance with user’s requirements. And manual coating, auto coating, pre-solidifying alarm and auto degassing are easily achieved depend on PLC control.
Figure 7. Ladder diagram for motor running.
C. the Quantitative Coating System Servo motors and metering pumps are the key units of the Quantitative Coating System. Servo motors convert electrical signals received to the angular displacement or angular velocity of axis. They smoothly run and can achieve highprecision position control. In the Intelligent-control Coating System, servo motors simultaneously drive the two plungers of metering pump to accurately and placidly discharge. Because the velocity of servo motor is adjusted, the coating velocity is also adjusted and an arbitrary proportion of raw materials can be achieved.
The connecting method of servo motor is very strict. Its power lines and earth line must be in one-to-one correspondence with the connection terminals of servo driver. Otherwise the servo motor can not run. And the servo motor encoder must also be in one-to-one correspondence with the connection terminals of servo driver. Otherwise the driver reports error. The connecting diagram of servo motor is shown in Figure 8.
2) Script Program of MCGS In user interface of MCGS, the proportion of raw materials can be adjusted through modifying script program. The formulas applied in the script program are as following:
QC1 UC N
1.5mm r s R S P U V W
red white black green
14 CN1 16 15 17
Shielded TwistedPair Cable R=2K +24V
Figure 8. Connecting diagram of servo motor. 
SUMMARY AND PROSPECT
The Intelligent-control Coating System is successfully developed depend on the combination of PLC, MCGS and the servo system. The system runs steadily and velocity and the proportion/ratio of raw materials are arbitrarily adjusted. And even replacing raw materials is no longer a difficult task. It provides a convenient for diversification of cots production and is a highly cost-effective control system. It also won development advantage for customers.
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