| The flannel shearing machine is one of the main equipments in the finishing process of textile. In order to improve the surface feel and comfort of the fabrics, we always fluff them with the raising machine after dyeing and stenter. But the fuzz formed on the fabric is always of various lengths, so we need to cut these fuzz into fixed length with the shearing machine to improve its quality and grade.For nearly a decade, China’s textile industry obtained a great development, and the pace of the industry upgrading becomes faster and faster. As an important part of the textile, dyeing and finishing industry is transforming from scale expansion to technology-intensive. With the rising economic status of China in the international, Chinese enterprises are increasingly involved in international competition. To enhance competitive strength, most enterprises try to improve their product quality and reduce the cost of production. Especially the environmental issues become more and more prominent now and our government is always advocating energy-saving and cost-reducing, dyeing and finishing enterprises urgently need to upgrade their automation level and production efficiency.Qingdao BaoLuLai Knitting corporation engaged in fabric after-treatment processing such as printing, dyeing and shearing. The shearing machine is directly related to the quality of the products, so there must be an efficient and reliable control system. This subject designs the system from three layers based on the understanding of the shearing machine, these layers include "monitoring layer","control layer" and "equipment layer". We use Siemens touch screen as the HMI in monitoring layer and use PLC and distributed I/O equipment in control layer, and these field equipments always include executing agencies such as converters. In another side, we adopt PROFIBUS-DP as the communication network of our system. As the master of the network, Siemens PLC S7-300is responsible for the processing of real time data. Those sub-stations such as ET200L and MM440converters transmit informations with PLC by PROFIBUS-DP network.Siemens MM440converter can be controled by several ways, such as V/F control and Vector control with encoder. In our speed control system, V/F control mode is used for lesss precision motors while Vector control is used for high precision motors.Tension control is an important part of this subject, because it will influence the quality of the production. In connection with the characteristics of the shearing machine and the actual requiement, we can control the tension with "speed chain" in which we can regard the speed of cloth guide roller as the standard speed and other rollers’speed can be controled based on different tension coefficient. Since we can control the speed smoothly, we can control the tension smoothly too.This subject introduces the shearing machine control system mainly from hardware and software. The hardware design mainly includes device selection and configuration, and software design mainly includes PLC program, communication process and HMI configuration. |
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