## 3 Results and Discussion
### Evaluation of the Test Series to Determine the Immersion Frequency and Dwell Time
#### 3.1.1 Light Microscopic Analysis of the Textiles  
The applied finish is recognisable at a magnification of 10\(\times\) under an optical microscope. The individual particles of the flame-retardant finish look spherical and darker than the textile \"KlevoGlass 550\". The shape of the particles of the flame-retardant finish makes it possible to compare the amount of flame retardant on the glass fibre filaments of the fab  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Trial**} & \multirow{2}{*}{**Surface Weight [g/m\({}^{2}\)]**} & **Average Surface Weight [g/m\({}^{2}\)] (Incl. Flame Retardant and PU-Based Adhesive)** \\ \hline
1.1 & 644 & \\
1.2 & 633 & 639 \\
1.3 & 641 & \\ \hline
2.1 & 636 & \\
2.2 & 644 & 649 \\
2.3 & 666 & \\ \hline
3.1 & 636 & \\
3.2 & 637 & 643 \\
3.3 & 655 & \\ \hline
4.1 & 647 & \\
4.2 & 654 & 653 \\
4.3 & 659 & \\ \hline
5.1 & 649 & \\
5.2 & 644 & 646 (only adhesive) \\
5.3 & 644 & \\ \hline \hline \end{tabular}
\end{table}
Table 8: Surface weights of the samples of the final test series with adhesive on the anchor peptides (samples 4.1–5.3 are different batches of the adhesive with the same formulation).  
rics. The samples were analysed by optical observation and comparison of the photographs taken by optical microscopy. Figure 3 shows representative microscopy images from the series of tests to determine the dwell time. Magnifications of 10\(\times\) and 20\(\times\) are shown side by side. The images are arranged vertically at different parameter levels. The images are compared in terms of the quantity of flame-retardant particles and the distance between the flame-retardant particles and the glass fibre filaments.  
Compared to the other samples in Figure 3, the largest amount of flame retardants can be seen on the surface of sample \"5-60\". The smallest amount of functionalised flame retardants is present on sample \"20-30\". The dark dots in the figures are the functionalised anchor peptides. It can be clearly seen that there are more dark dots on the glass fibre filaments in the marked areas of sample \"5-60\" than in the marked areas of sample \"20-30\"; see Figure 4.  
A comparison of samples \"5-60\" and \"5-30\" as well as samples \"20-60\" and \"20-30\" shows that after a longer dwell time (60 min), more functionalised flame retardants can be seen on the surface of the textile than with a shorter dwell time (30 min). The dwell time has a positive influence on the finishing with anchor peptides.  
A comparison of the microscopy images of the fabric samples \"5-60\" and \"20-60\" as well as \"5-30\" and \"20-30\" shows that the immersion frequency of the textiles has a slight negative influence on the amount of functionalised flame retardant on the surface of the fabrics. The amount of flame retardant on the surface of the textiles is greater at a lower immersion frequency (0.14 Hz) of the textile than at a higher immersion frequency (0.56 Hz).  
The textile finishes are further assessed by comparing the impregnated textiles with each other. The assessment is made in three categories: strong/high (1), moderate (0.5) and low (0). The results are summarised in Table 9.  
Figure 3: Microscopy images from the test series to determine the dwell time and the immersion frequency at 10\(\times\) and 20\(\times\) magnification. Flame retardants are highlighted; 1-5: Pulled off once; 5-30: 5 Hz motor frequency, 30 min dwell time; 5-60: 5 Hz motor frequency, 60 min dwell time; 20-30: 20 Hz motor frequency, 30 min dwell time; 20-60: 20 Hz motor frequency, 60 min dwell time.