Abstract
Cup transport systems are machines that print on plastic cup, and air nozzles are used to separate, hold, and release the cup. Since air nozzles release high-pressure air into the atmosphere, fluid noises, e.g. 96.3dB from printing mandrel part and 90.8dB from supply spiral nozzle, are generated by the air jet, and it cause to worse work environment. The purpose of this study is to investigate the noise characteristics of the supply spiral nozzle (actual nozzle) used in a cup transport system and to take measures to reduce noise. In the experiment, compressed air was supplied from an air compressor, and the noise level, cup flying distance, and jet velocity were measured. As a result, it was found that the noise level of the actual nozzle tends to become large as the downstream direction, and that the noise was greatly affected by the jet flow from the outer hole compared with that from inner hole. It was also found that the noise increased in proportion to the 4.5th power of the jet velocity and the 4th power of the equivalent diameter of the jet outlet. As a result of the noise reduction measure, 5dB of noise was reduced by using the nozzle with hole diameter of 0.8mm and 6 holes.
