With the increasing cost of labor and energy as a share of production costs and the impact of environmental pollution on health, how to increase the intelligent feeding of powder raw materials in the PVC pipe extrusion line and reduce the production cost and increase The accuracy of PVC compound has always been the goal we have been pursuing.
In the centralized feeding section for extruder hoppers, the following problems generally exist:
The centralized feeding of PVC raw material in the feeding hopper of the extrusion unit is usually transported to many extruding machines over a long distance by a pipe chain or a spiral type. A level switch is set on each extruder hopper. Once one of the hoppers The lack of material requires the conveyor to operate immediately to feed the material, which results in frequent start / stop of the conveyor, which greatly affects the stability of the equipment. In addition, once any one of the low level switches fails, the extruder stops down. Failure of the high level switch will cause the conveyor to jam because of continuous operation.
Conventional extruder centralized feeding is generally quantitative parallel transfer, PVC powder out of the hopper inside the consumption process, the material level changes greatly in the feeding process is likely to cause "red" and cutting discontinuities (Bridging) phenomenon, leading to easy to break the screw extruder, and more importantly, extrusion molding of plastic products by the uneven quantitative feeding problems lead to product quality problems of uneven wall thickness.
In order to solve the problems existing in the centralized transportation of PVC powder, DSG Group provides users with effective solutions. The feeding system adopts programmable logic controller to control the start of the main motor of each extruder downstream of the whole pipe chain. Speed and other signals collected, and then calculated according to the speed of the extruder signal to control the amount of feed extruder, and then through the feed volume calculated for each production line for the amount of feed, and then feed Volume converted into the conveyor chain speed, in real time on the conveyor chain speed regulation.
When the downstream extruder main motor speed suddenly increases or the number of extruder operation increases, along with the feeding system will immediately detect the speed changes and increase the amount of material, the corresponding increase in feeding speed, and then the corresponding proportion On the other hand, when the speed of the downstream main motor is suddenly reduced or the number of extruders is reduced, the feeding system accordingly reduces the feeding speed and at the same time reduces the proportion of the delivery of the chain speed.
In addition, the feeding system also reads the current and torque parameters of each downstream extruder. When the extruder super torque alarm, the feeding system will automatically shut down the corresponding pipe conveyor pipe of the extruder Discharge port, and stop the feeder, and then ensure that the extruder feed volume is no longer increased, so that the extruder output torque down, effectively protecting the extruder screw.
In the flexible long distance, multi-station powder conveying also has a unique full-material redundant pressure relief mechanical design to ensure that in extreme cases: even if most of the hopper in the extruder is full of material, but also Make sure the tube chain in the operation of "scraper" produced by the effective pressure of the powder without leakage.
In addition, through the control of the stable extrusion volume, the product "rice weight" is relatively constant, so as to ensure uniform product wall thickness. Due to the uniform wall thickness, the quality of the product is guaranteed while saving material consumption.
The entire feed system controller connects downstream 13 extruder systems via Ethernet switches and network cables and establishes communication via MODBUS TCP / IP protocol. For the entire system control provides a reliable connection. Feeding system can also establish a remote operation monitoring system through communication gateway and safety communication module. Thereby increasing the automation of the entire system, the degree of information.
The "Smart Feeding" solution from DSG: Dynamic and uninterrupted operation and timely adjustment of the throughput by collecting a series of critical data from all downstream downstream extruders in real time and assisting in the extrusion of excess hopper in extreme conditions Pressure relief mechanical structure. This can effectively improve production capacity, promote the transformation of traditional enterprises to intelligent enterprises, while reducing costs while greatly improving efficiency, while ensuring product quality, and thus open up a broader market.