Electrostatic spraying is to coat polymer coating particles on grounded metal objects by electrostatic adsorption, and then send them into an oven to form a coating with uniform thickness. The corona discharge electrode charges paint particles with a diameter of 5 ~ 30 microns, and under the action of conveying air and electrostatic force, the paint particles fly to the coated object, and the adsorption force between the charges carried by the particles and the induced charges on the coated object makes the paint firmly adhere to the coated object. Generally, the thickness of the coating can reach 40 ~ 50 microns after 2 ~ 3 seconds. Charging, flying and coating of paint particles are important processes in electrostatic spraying process, which determine the quality and efficiency of electrostatic spraying system. (1) charged coating particles. Ion bombardment near the corona discharge electrode charges the coating, which is a function of the electric field intensity near the electrode and the speed of particles flying over the area. The charge performance of coated particles is usually described by the charge-to-mass ratio (Coulomb/kg). In order to achieve firm suction, the average charge-mass ratio should be 5× 10-4 coulombs/kg. ② Transfer of paint. After the paint is charged, it flies to the coated object under the action of conveying air force, and finally attracts its surface by electrostatic force. For any spraying system, high transfer efficiency is expected, which is related to nozzle voltage and paint flow, and should be considered comprehensively in practical operation. Electrostatic spraying technology is widely used in manufacturing instruments and electrical equipment to strengthen insulation, external protection of components and external insulation of conductors. Electrostatic spraying is to charge the paint mist sprayed by the spray gun under the action of high-voltage electrostatic field. This charged paint mist is adsorbed to the surface of the workpiece with different charges and deposited into a uniform coating. The utilization rate of electrostatic spraying paint solution is very high, which can reach 80 ~ 90%. Mainly used in automobile, machinery, household appliances and other industries. Both electrostatic sprayers and electrostatic dusters for spraying pesticides are equipped with electrostatic nozzles. The electrostatic nozzles are charged by a high-voltage DC power supply of hundreds to thousands of volts, so that the liquid medicine or powder particles are charged, while the control target generates charges with opposite polarity through electrostatic induction, so that the liquid medicine or powder particles run towards the control target under the action of electrostatic field. Using static electricity can significantly improve the hit rate, reduce the loss of chemicals and environmental pollution, and spray chemicals on the back of the target to enhance the prevention and control effect. In the spinning process of electrostatic spinning, the fibers are straightened, arranged and condensed by the force of electrostatic field, and play a balancing role when the free end is added, so that the spinning can be carried out continuously. It is a new spinning technology and belongs to the category of open-end spinning. The United States first conducted research in 1949, and now the world is still in the stage of theoretical discussion and experiment, and has not yet reached the scale of industrial production. China started research from 1958, and now a pilot plant has been established, which can stably produce dozens of varieties. The electrostatic spinning device consists of four parts: single fiber supply mechanism, electrostatic field generator, drafting device and winding mechanism. The main technological processes are wet drawing, low-speed carding, air stripping, electric field directional arrangement in closed containers, and high-speed rotary drawing to form yarn. The existing problems are that there are many yarn defects, and the labor productivity and economic benefits can't keep up with the traditional spinning process. But its advantages are high output, large molding, integration of roving, spinning and bobbin, and power saving. Especially in the production of core-spun yarn slubs, colored slubs and blending, it can better reflect the advantages of electrostatic spinning. Electrostatic flocking uses electrostatic field to polarize fluff and arrange it along the direction of electric field, and at the same time, it is absorbed on the substrate coated with adhesive to become fluff products. The device consists of two parallel plate electrodes. Wherein the lower electrode is grounded, and a base material and short fibers are placed thereon; High voltage direct current is applied to the upper electrode plate to form a strong electric field between the two electrodes. Taking suede products as an example, its working process is as follows: connect the negative pole of 35 ~ 60 kV high-voltage power supply to the metal mesh frame filled with fluff, put the substrate coated with adhesive on the metal bracket and connect it to the positive pole of power supply, so that an electrostatic field is formed between the metal mesh frame and the metal bracket. After passing through the metal mesh, the formed fluff enters the electric field and is polarized, so that it rotates parallel to the direction of the electric field, settles on the substrate and is adhered to form flocking products. At present, the main product types are: carpet, cushion, artificial fur, printed flannel and other fiber products; Plastic products, such as decorative cloth, protective sound-absorbing cloth and products that give surface elasticity; Metal products include decorative materials, protective materials and thermal insulation materials; Others are wooden shells and paper shells used for decoration. Electrostatic copying is to use photoconductive photosensitive materials to transfer charges according to the image when exposed, leaving electrostatic latent images, and then get copies through certain dry development, image transfer and fixing. The material used is non-silver photosensitive material. There are two kinds of xerography: direct method and indirect method. The former copies the original image directly on photosensitive paper coated with zinc oxide, also known as coated paper copier; The latter is to first change the original image into an electrostatic latent image on the photoreceptor, and then transfer it to ordinary paper, so it is also called ordinary paper copier. According to whether the developer is dry powder or liquid, it can be divided into dry type and wet type. At present, countries all over the world mainly produce dry indirect electrostatic copiers. Commonly used photocopying materials include inorganic photoconductive materials such as zinc oxide, selenium and cadmium sulfide, and organic photoconductive materials such as polyvinyl carbazole (PVK) and trinitrofluorone (TNF). The process of xerography is as follows: first, the photosensitive layer is uniformly charged; Then use the manuscript for reflection exposure; The electrostatic latent image is formed due to the different charge densities of the photoconductive layer of the lighting part, and is covered with thermoplastic toner for dry development (development); Cover the photosensitive layer with white paper, recharge and transfer the image.