**3.1 Thickness**

248 Thermoplastic Elastomers

**Collector vacuum (%)** 

**Die air pressure (psi)** 

**Extruder pressure (psi)** 

**Fabric No Collector drum** 

**speed (ft/min)** 

Table 2. Sample codes and production parameters of PP nonwovens

Thickness was tested by using SDL Thickness Gauge according to TS 7128 EN ISO 5084 standard, with 20 cm2 measurement area under 200 g weight. Air permeability test was performed by using FX 3300 Air Permeability test device according to TS 391 EN ISO 9237 standard, with 20 cm2 measurement area and 100 Pa air pressure. Fiber diameter was measured by using Leica DM EP light microscope with 400 zoom. Tensile properties were tested according to TS EN ISO 13934-1 standard by using Zwick Z010 Universal tensile

The results were evaluated statistically by using SPSS software. To evaluate the differences between the subgroups in the collector drum speed, the collector vacuum and the die air pressure Student-Newman-Kleus test were performed. For the investigation of the effect of

strength with 200 mm measurement distance and 100 mm/min measurement speed.

the extruder pressure 2-Tailed Pearson Correlation tests were performed.

The results obtained from the thickness measurements were presented in Figure 1. The statistical analysis have shown that thickness of polypropylene meltblown nonwovens were effected mostly by the drum speed and the collector vacuum. An increase in the drum speed and an increase in the vacuum caused a decrease in the thickness. In other words, thicker surfaces were obtained with lower collector drum speeds and lover vacuum values. The highest values were obtained with 10 ft/min drum speed and %15 vacuum.

Fig. 1. Thickness values of polypropylene meltblown nonwovens

Statistical analyses also proved that the drum speed and collector vacuum on the thickness of meltblown nonwovens were statistically significant. The results of the tests between subgroups were shown in Table 3 and Table 4. As it can be seen in Table 3 and Figure 1, as a general trend the thickness increased with decreasing collector drum speed. Even though the thicknesses of the samples produced with 30 ft/min which were 0,0278 cm on average are slightly higher than the ones produced with 20 ft/min which were 0,0197 cm, the main trend did not change. The highest results were obtained with 10 ft/min as 0,0789 cm and the lowest results were obtained with 20 ft/min as 0,0197 cm.

As it can be seen in Table 4 and Figure 1, the effect of collector vacuum on the thickness was found to be statistically significant and the thickness increased with decreasing collector vacuum. The highest thickness results were obtained with 15% as 0,0602 cm and the lowest results were obtained with 60 ft/min as 0,0254 cm.

Investigation of the Production Parameters and

**Extruder pressure (psi)** 

**Thickness (cm)** 

on to the thickness

**3.2 Basis weight** 

Physical Characteristics of Polypropylene Meltblown Nonwovens 251

**Correlations Extruder** 

Table 6. 2-Tailed Pearson Correlation test results related with the effect of extruder pressure

The results obtained from the basis weight measurements were given in Figure 2. The basis weight of the polypropylene meltblown nonwovens were effected mostly by the die air

\*. Correlation is significant at the 0.05 level (2-tailed).

Fig. 2. Basis weight values of polypropylene meltblown nonwovens

30 45 137,033

20 45 190,824

10 45 239,769 Sig. 1,000 1,000 1,000

Table 7. Student-Newman-Keuls test results related with the effect of the collector drum

**Collector Drum** 

Alpha = 0,05

speed on to the basis weight

**Speed (ft/min) N** 

pressure, collector drum speed and collector vacuum.

Pearson Correlation 1 ,197\* Sig. (2-tailed) ,022 N 135 135

Pearson Correlation ,197\* 1

N 135 135

**Subset**  1 2 3

Sig. (2-tailed) ,022

**Pressure Thickness** 


Table 3. Student-Newman-Keuls test results related with the effect of collector drum speed on to the thickness


Table 4. Student-Newman-Kleus test results related with the effect of collector vacuum on to the thickness

The effect of air pressure on the thickness was also found to be statistically significant, when the difference between 6 psi and 8 psi were considered. Student-Newman-Keuls test results showed that an increase in the die air pressure caused the increase in the thickness. The results of the tests between subgroups were presented in Table 5. As it can be seen in Table 5, the thickness value increased from 0.362 cm to 0.431 cm by the increase of the die air pressure from 6 psi to 7 psi. Similarly, when the pressure increased to 8 psi, the average thickness increased to 0,047 cm.


Table 5. Student-Newman-Keuls test results related with the effect of die air pressure on to the thickness

The results obtained from the 2-Tailed Pearson Correlation test were given in Table 6. The results showed that there was a positive correlation of 19,7% between the die air pressure and the thickness, which means that increase in the die air pressure caused an increase in the thickness in 19,7%.


Table 6. 2-Tailed Pearson Correlation test results related with the effect of extruder pressure on to the thickness
