## 1 Introduction  
At present, the situation of China's environmental problems is very serious, and air pollution, as one of the main representatives, is receiving more and more attention. Dust is the main factor of air pollution, especially as the most typical ones are PM\({}_{2.5}\) and PM\({}_{10}\), which can cause a series of environmental problems such as haze, ozone layer destruction, the reduction of atmospheric visibility, and the greenhouse effect [1; 2; 3; 4; 5]. Coal-fired power plants are one of the important sources of dust emissions. The state has issued a series of policies and measures to strictly control the emission of air pollutants from coal-fired power plants. In 2015, the Ministry of Environmental Protection, the Development and Reform Commission, and the National Energy Administration jointly issued a notice on the \"Comprehensive implementation of the work plan of ultra-low emission and energy-saving transformation of coal-fired power plants\", and put forward the requirements of ultra-low emission and ensuring the energy-saving operation of environmental protection equipment for the pollutant control of coal-fired power plants [2; 4]. In recent years, the electrostatic-fabric integrated precipitator and bag filter have achieved good results in the treatment of dust and particulate pollutants, but the filter bags on the market are various and the effect is uneven, so the development of an excellent performance of filter bags has important significance [6; 7; 8; 9; 10; 11].  
Under the increasingly stringent national emission standards, the dust emission of coal-fired boilers has been controlled below 10 mg/Nm\({}^{3}\), but the problem of fine dust emission has not been completely resolved. The removal of fine dust has become one of the mainstream directions of the current development of dust removal technology [5; 12; 13]. The main idea for removing fine dust is to combine fine dust into dust with a large particle size and then remove it. The methods mainly include electric coalescence, magnetic coagulation, steam phase change condensation, chemical agglomeration, etc. Among them, electric coagulation is the most commonly used technical means in coal-fired power plants [14; 15; 16]. As one of the mainstream dust removal technologies for coal-fired power plants in China, the electrostatic-fabric integrated precipitator is also facing technological innovation and upgrading under the background of ultra-low emissions in coal-fired power plants. The focus is to further improve the dust-removal performance of the electrostatic-fabric integrated precipitator while ensuring its low resistance operation [17; 18; 19; 20].  
The bag area is an important part of the electrostatic-fabric integrated precipitator, and the filter bag is the core component of the bag area [21]. The filtering performance of the filter bag directly affects the dust removal efficiency and running resistance of the dust collector [21; 22; 23]. At present, the commonly used basic filter materials are polyphenylene sulfide (PPS), polyimide (PI), polytetrafluoroethylene (PTFE), and so on [24; 25; 26; 27; 28]. In addition to the filter performance of the filter bag being affected by its material, factors such as weight, surface treatment process, and formula are also crucial. However, there is still very little research on filter bags. Therefore, it is of great significance to carry out comparative experiments on the filtering performance of filter materials with different materials, different weights, different surface treatment processes, and different formulations to guide the industrial application of filter bags.