Automatic screen printing equipment for plastic straightedge based on PLC

YUAN Yun-long1， YUAN Rui-long2， CHENG Hong1
（1. College of Mechanical Engineering， Ningbo University of Technology， Ningbo 315016， China；
2. United Engineering Corporation of China， Hangzhou 310022， China）

Abstract： In order to solve the problems of surface scratch and inefficiency during the screen printing of plastic straightedge，a novel scheme for material feeding was proposed，in which the horizontal upright，longitudinal stack，and longitudinal sucking mode was used. A granary and feed equipment capable of continuous feeding was designed. The surface scratch was eliminated by using pneumatic actuator. Also，a PLC control system was developed for the entire working process. The two steps of sucking disc rotation and printing table rise were controlled independently and thus the parallel operation was achieved. By using this equipment，the transport efficiency of straightedge was improved. Practical application of the proposed equipment shows that the straightedge surface is not scratched and the equipment has a high reliability and production speed reaching 28 rulers per minute.
Key words： screen printing； plastic straightedge； PLC； automatic control