## 2 Experimental Materials and Methods
### Experimental Method  
The experiment uses the FEMA 1-AT (normal temperature type) filter material filtration performance test platform produced by FiIT Eq, Germany (Figure 1), examines several filter materials of different materials and different processing techniques listed in Table 1, and measures their particle collection efficiency under different working conditions (constant pressure soot cleaning resistance, inlet dust concentration, filtering velocity, etc.). The preparation, testing, and calculation of the filter media samples for the experiment were based on the German standard VDI 3926-2004 and the Chinese national standard \"Technical Requirements for Baghouse Dust Collectors\" (GB/T 6719-2009). The test principle is: the dust was supplied through the precision spiral dust collector and introduced into the square vertical tube by the airflow, the dust concentration was 5 g/m\({}^{3}\). The filter media sample was cut to the right size and clamped at the intersection of the horizontal and vertical tube. Under the suction of the vacuum pump, the dust-containing airflow passed through the tested filter media and the dust was trapped by the filter media. The filtering velocity was 2 m/min, the blowing pressure was 500 kPa, the pulse jet time was 50 ms, and the dust used for the test was Pural NF alumina dust produced in Germany with the particle size distribution as shown in Figure 2. The standard test conditions are shown in Table 2. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & **Class** & \begin{tabular}{c} **Gram Weight** \\ **(g/m2)** \\ \end{tabular} & \
\begin{tabular}{c} **Breathability** \\ **(L/dm2\({}^{2}\cdot\)min)** \\ \end{tabular} & **Texture** &
\begin{tabular}{c} **Experimental** \\ **Type** \\ \end{tabular} \\ \hline
1 & PPS fiber & 544 & 148.68 & PTFE & \\
2 & PI fiber & 560 & 192.48 & PTFE & Different \\
3 & PTFE fiber & 730 & 126.44 & PTFE & fiber material \\
4 & PPS fiber & 536 & 167.48 & PPS & Different \\
5 & PPS fiber & 589 & 111.58 & PPS & gram weight \\
6 & PPS fiber by surface & 540 & 178.84 & PTFE & Different surface \\
7 & impregnation & 50\%PPS + 50\%PTFE) fiber & 614 & 109.22 & PTFE & \\
8 & (70\% common PPS + 30\% & & & \\
8 & superfine PPS) fiber & 533 & 129.68 & PTFE & Different mixed \\  & (Blended ultrafine) & & & & formulas \\
9 & (70\% common PPS + 30\% & & & \\
9 & superfine PPS) fiber & 612 & 119.59 & PTFE & \\  & (gradient filter) & & & \\
10 & PPS fiber coating a membrane & 555 & 25.40 & PTFE & \\
11 & (50\% PPS + 50\% PTFE) fiber & & & \\ coating a membrane & 621 & 13.86 & PTFE & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Basic parameters of the experimental sample. Figure 1: Filter material filtration performance test platform. The test process was divided into four stages: cleaning, aging, stabilization, and measurement. The filter media was repeatedly filtered and back blown through these 4 stages. The performance of the filter media in the actual dust removal project was examined through the results of the 4 stages of operation in the system. The test steps were as follows:  
1. Clean filter media sample filtration stage: Install the filter material sample on the filter material fixture, the diameter of the filter material sample was \(\varphi\)150 mm. When the pressure reached 1000 Pa, the pulse valve automatically opened for dust cleaning. The test time was recorded after 30 repetitions, the weight gain of the high-efficiency filter membrane was measured, and the exit dust concentration was calculated. 2. Aging treatment stage: Aging experiments were conducted on the experimental filter media, and back-blowing pulse cleaning was forced at 5 s intervals, with 10,000 repeated blows, and the process lasted for about 14 h. During the aging process, the pulse jet time was 50 ms, and the vacuum pump was kept working. The continuous blowing caused the filter media to repeat the process of tensioning and relaxing under the strong influence of changing airflow, which aggravated the aging of the filter media. 3.