## 3 Results
### Airflow Resistance  
The mean airflow resistance values for the nonwoven composite materials containing zeolite and silica materials are given in Table 6 with the relative results shown in Figure 12. Deterioration of protective and functional properties of the composite materials in relation to the reference sample is marked with negative values, while the improvement of protective and functional with positive values. On the basis of the statistical analysis performed, significant differences for the average air flow resistance values are marked with different letters.  
The lowest airflow resistance was found for the composites PPQ + Na-A HDTMA, PPQ + SM, and PPQ + SM 4A, at 306.25 Pa, 283.50 Pa, and 268.00 Pa, respectively. The corresponding relative airflow resistance values were 17.41, 8.69, and 2.75%, respectively, as compared to the reference  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**No.** & **Variant** & **Mean Airflow Resistance, Pa** & **Standard Deviation** & **Median** & **MAX, Pa** & **MIN, Pa** \\ \hline
1 & PPQ + MCM-41 & 331.50 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 14.38 & 334.50 & 348.00 & 313.00 \\
2 & PPQ + Na-A & 648.00 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 73.39 & 655.00 & 747.00 & 489.00 \\
3 & PPQ + Na-P1 & 537.14 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 40.37 & 520.00 & 590.00 & 485.00 \\
4 & PPQ + SM & 268.00 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 4.69 & 266.50 & 275.00 & 261.00 \\
5 & PPQ + SM & 289.50 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 34.32 & 278.50 & 338.00 & 250.00 \\
6 & PPQ + MCM-41 HDTMA & 876.80 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 36.42 & 851.00 & 940.00 & 848.00 \\
7 & PPQ + Na-A HDTMA & 306.25 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 27.49 & 308.50 & 341.00 & 287.00 \\
8 & PPQ + Na-P1 HDTMA & 517.40 [FOOTNOTE:]Footnote : \(\alpha\)= 0.05; [PERSON]’s test, \(\alpha\) = 0.05).[ENDFOOTNOTE] & 73.48 & 539.00 & 593.00 & 386.00 \\
9 & Pure PPQ reference sample & 260.83 & 8.82 & 260.50 & 272.00 & 248.00 \\ \hline \hline \end{tabular}  
* statistically significant differences were found for the mean values marked with different letters (ANOVA, \(\alpha\) = 0.05; [PERSON]’s test, \(\alpha\) = 0.05).  
\end{table}
Table 6: Mean airflow resistance values for nonwoven composites containing zeolite and silica materials (descriptive statistics).  
Figure 12: Relative change in airflow resistance for nonwoven zeolite and silica composite.  
sample. The introduction of additives during the nonwoven production process resulted in a slight increase in airflow resistance relative to the reference sample. In the case of the composite containing PPQ + MCM-41, airflow resistance increased by 27.1%.  
The highest airflow resistance was found for the nonwoven composites containing zeolites Na-A and Na-P1, and modified silica MCM-41 HDTMA at 648.00 Pa, 537.14 Pa, and 876.80 Pa, respectively, with the corresponding relative changes of 148.43, 105.93, and 236.15%. The increased airflow resistance is associated with clogging by zeolite and silica particles, which filled the interfiber spaces. According to the EN 149:2001+A1:2009 clogging test, airflow resistance must not exceed 700 Pa at a flow rate of 95 L/min. The above criterion was not met for the composite containing the modified silica material MCM-41 HDTMA.