**3.2 Basis weight**

250 Thermoplastic Elastomers

**Subset** 

**1 2 3** 

**Subset** 

**1 2 3** 

**Subset 1 2** 

**Collector DrumSpeed** 

Alpha = 0,05

**Collector Vacuum** 

Alpha = 0,05

**(%) N** 

60 45 ,0254

**Die Air Pressure (psi) N** 

Alpha = 0,05

6 45 ,0362

7 45 ,0431 ,0431 8 45 ,0470 Sig. ,061 ,287

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

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

on to the thickness

the thickness

the thickness

the thickness in 19,7%.

thickness increased to 0,047 cm.

**(ft/min) N** 

20 45 ,0197

30 45 ,0278

30 45 ,0407

10 45 ,0789 Sig. 1,000 1,000 1,000

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

15 45 ,0602 Sig. 1,000 1,000 1,000

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

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 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 pressure, collector drum speed and collector vacuum.

Fig. 2. Basis weight values of polypropylene meltblown nonwovens


Table 7. Student-Newman-Keuls test results related with the effect of the collector drum speed on to the basis weight

Investigation of the Production Parameters and

**3.3 Air permeability** 

on the basis weight was not statistically significant.

permeability results were presented in Figure 3.

Fig. 3. Air permeability values of polypropylene meltblown nonwovens

values were obtained with 8 psi as 275,444 g/m2/l.

**Die Air** 

Alpha = 0,05

on to the air permeability

**Pressure N** 

8 45 275,444

7 45 330,789

6 45 347,056 Sig. 1,000 1,000 1,000

Table 11. Student-Newman-Kleus test results related with the effect of the die air pressure

As it can be seen in Table 11, the die air pressure had a significant effect on the air permeability of the polypropylene meltblown nonwovens. Table 11 and Figure 3 showed that the air permeability increased with increasing die air pressure. It can be also said that the air permeability was effected by the weight of the sample and it increased by decreasing weight. The highest results were obtained with 6 psi as 347,065 g/m2/l, whereas the lowest

> **Subset 1 2 3**

Physical Characteristics of Polypropylene Meltblown Nonwovens 253

there was not any significant correlation, which means that the effect of extruder pressure

Air permeability is an important property for meltblown nonwovens, that effect their performance in many applications especially in filtration. The air permeability property of the meltblown nonwovens are mostly effected by the die air pressure, the collector drum speed, the collector vacuum and extruder pressure. The results obtained from air

Table 7 and Figure 2 showed that the basis weight increased gradually with decreasing collector drum speed. The highest values were obtained with 10 ft/min collector drum speed as 239,769 g/m2 on average and the lowest values were obtained with 30 ft/min collector drum speed as 137,033 g/m2 on average.

As it can be seen in Figure 2 and Table 8, basis weight increased also with increasing die air pressure. The highest values were obtained with 8 psi as 322,711 g/m2, whereas the lowest values were obtained with 6 psi pressure as 31,411 g/m2.


Table 8. Student-Newman-Keuls test results related with the effect of the die air pressure on to the basis weight

Student-Newman-Keuls tests have also shown that the collector vacuum had a significant effect on basis weight and also that when the vacuum increased the weight also increased. So the highest values were obtained with 60% vacuum as 220,720 g/m and the lowest values were obtained with 15% vacuum as 171,902 g/m as it can be seen in Table 9 and Figure 2.


Table 9. Student-Newman-Kleus test results related with the effect of the collector vacuum on to the basis weight


Table 10. 2-Tailed Pearson Correlation test results related with the effect of extruder pressure on to the basis weight

The results of the 2-Tailed Pearson Correlation test applied to see the relationship between the extruder pressure and the basis weight were given in Table 10. The results showed that there was not any significant correlation, which means that the effect of extruder pressure on the basis weight was not statistically significant.
