| With the development of functional films in emerging industries such as solar cells,fuel cells,flexible conductive coatings,fuel cell electrode coatings,OLED light-emitting panels and flexible displays,the requirements for functional film preparation technology are also increasing.Compared with traditional pressure spraying and electrostatic spraying,piezoelectric spray coating can effectively improve the uniformity and preparation efficiency of coating preparation,and provide a key driving role for the further development of coating preparation technology,The main research on piezoelectric spraying technology is the research on key components of piezoelectric nozzles and the research of coating preparation system.Firstly,this paper deals with the structural design and theoretical calculation of the core part of the piezoelectric nozzle.In order to overcome the problems of small atomization amount,poor reliability and large spray particle size and uneven atomization in low-frequency piezoelectric nozzles,this paper intends to design a new type of piezoelectric atomizing nozzle.The horn of the nozzle is designed as a step compound type variable amplitude with a large amplification factor and a small stress concentration.so as to achieve a large amount of atomization and a small atomization droplet size,the design frequency of the piezoelectric nozzle is about 100 kHzSecondly,according to the atomization performance of the piezoelectric nozzle,structural design and simulation optimization are performed to determine the overall structure of the piezoelectric nozzle and the size of each component.The theoretical model of the nozzle is established and the simulation is optimized.The modal analysis results show that the natural frequency of the nozzle is 104502Hz,and the design frequency error is within 5%.The harmonic response analysis of the nozzle is carried out.When the frequency of the nozzle is consistent with its natural frequency to reach resonance,the amplitude of the nozzle is 4.68?m,which can meet the atomization requirement.The fan-shaped gas nozzle spray angle designed in this paper reaches about 85°,which can obviously improve the dispersibility and atomization effect of the mist.Again,the performance of the designed piezoelectric nozzle is tested.First,the optimal pre-stress range can be determined by theoretical calculations and actual prototype tests.Then there is the matching test between the piezoelectric nozzle and the power supply.When the power of the power supply is 1.2W,the nozzle can achieve better atomization effect.The atomization particle size test indicates that the average particle size of the piezoelectric nozzle is 22?m to reach the theoretical design requirement,and the proportion of the droplets between 10?m and 30?m is 75.08%,indicating that the atomization performance of the nozzle is good.The flow test shows that the atomization effect of the nozzle is better when the liquid flow rate is controlled between 0.3ml/min and 1.0ml/min.Finally,a functional coating is prepared using the piezoelectric nozzle.This nozzle is used to prepare flexible graphene conductive coating and hydrophobic coating.Graphene coatings of different thicknesses were prepared by adjusting various parameters of the nozzle,and the relationship between the number of layers of the sprayed graphene coating and the thickness,square resistance and light transmittance of the sprayed graphene coating was demonstrated through experiments.The hydrophobic angle of the hydrophobic coating prepared on the textile by piezoelectric spraying reaches about 150°,which indicates that the coating has good hydrophobicity and self-cleaning effect.The test of wear resistance indicates that the hydrophobic coating prepared by using the nozzle has Very good adhesion,... |
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