**3.4 Fibre diameter**

254 Thermoplastic Elastomers

Figure 3 and Table 12 show that, the air permeability increased with increasing collector drum speed. This result was thought to be related to the decrease in thickness and basis weight. The highest results were obtained with 30 ft/min as 452,267 g/m2/l, whereas the

> 30 45 452,267 Sig. 1,000 1,000 1,000

Table 12. Student-Newman-Kleus test results related with the effect of the collector drum

Regarding the effect of the collector vacuum on the air permeability, it can be said that the air permeability increased with decreasing vacuum. This can be due to the increase in the basis weight with increasing vacuum. The highest results were obtained with 15% as 382,156

The results of the statistical subgroup analysis about the effect of the collector vacuum on

15 45 382,156 Sig. 1,000 1,000 1,000

Table 13. Student-Newman-Kleus test results related with the effect of the collector drum

**Correlations Extruder** 

Table 14. 2-Tailed Pearson Correlation test results related with the effect of the extruder

Table 14 shows the correlation test results regarding the effect of the extruder pressure on the air permeability. As it can be seen in the table, the correlation was found to be statistically

Sig. (2-tailed) ,044

**Subset 1 2 3** 

**Pressure**

Pearson Correlation 1 -,174\* Sig. (2-tailed) ,044 N 135 135

Pearson Correlation -,174\* 1

N 135 135

**Air Permeability**

**Subset 1 2 3** 

lowest values were obtained with 10 ft/min as 184,122 g/m2/l.

10 45 184,122

20 45 316,900

g/m2/l, whereas the lowest values were obtained with 60% as 255,689 g/m2/l.

30 45 315,444

**Collector Drum Speed N** 

c. Alpha =0,05

the air permeability were presented in Table 13.

**Collector Vacuum N** 

Alpha = 0,05

60 45 255,689

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

speed on to the air permeability

speed on to the air permeability

Extruder\_pressure

Air\_permeability

pressure on to the air permeability

Fibre diameter of meltblown nonwovens plays a critical role in some physical properties of the meltblown nonwovens, as it determines the surface area, which is a very important parameter for such applications as filtration and cleaning. Better filtration and cleaning performances are achieved with smaller fibre diameter, due to the increased surface are. Fibre diameter was effected by the collector vacuum and the extruder pressure. Figure 4 showed the fibre diameter properties of polypropylene meltblown nonwovens. In this study meltblown nonwovens with fibre diameter of 5-9 m were achieved.

Fig. 4. Fibre diameter values of polypropylene meltblown nonwovens

As it can be seen in Table 15, results of the statistical analysis have shown that the die air pressure did not have a significant effect on the fibre diameter. It is also possible that the effect was not clear since the die air pressure values were very close to each other.


Table 15. Student-Newman-Kleus test results related with the effect of the die air pressure on to the air fibre diameter

Investigation of the Production Parameters and

breaking load.

Physical Characteristics of Polypropylene Meltblown Nonwovens 257

because orientation of the fibre were more towards the production direction around the

collector drum and therefore the strength was more enhanced in this direction.

Fig. 5. Breaking load values of polypropylene meltblown nonwovens

Fig. 6. Elongation values of polypropylene meltblown nonwovens

Figure 6 shows the elongation values in the production and the width directions. As it can be seen in Figure 6, the elongation results in production direction were slightly lower than the results in the width direction. In general, the elongation decreased with increasing

The effect of the collector vacuum on the fibre diameter was found to be statistically significant. As it can be seen in Table 16, the fibre diameter slightly increased from 6,89 m to 7,15 m, when the collector vacuum increased from 15% to 30%. The reason of this increase might be the increasing pressure on the fibres. It can also be seen in Figure 4 and Table 15 that the fibre diameter did not change significantly with an increase in the collector vacuum from 30% to 60%. The highest results were obtained with 60% as 7,345 m, whereas the lowest values were obtained with 15% as 6,900 m.


Table 16. Student-Newman-Keuls test results related with the effect of the collector vacuum on to the fibre diameter

Table 17 shows the correlation between the extruder pressure and the fibre diameter. As it can be seen in the table, the correlation was not found to be statistically significant, so the fibre diameter of the meltblown nonwovens investigated in this study were not influenced by the extruder pressure.


Table 17. 2-Tailed Pearson Correlation test results related with the effect of the extruder pressure on to the fibre diameter

#### **3.5 Tensile properties**

Breaking load and % elongation were investigated to evaluate the tensile properties of the meltblown nonwovens. The results of the measurements have shown that the breaking load and the elongation were significantly affected by the collector drum speed, collector vacuum, die air pressure and extruder pressure in production direction, where a the extruder pressure did not appear to be a significant factor for the tensile properties in the width direction.

Figure 5 shows the breaking load values of the polypropylene meltblown nonwovens in production and width directions. It can be seen in Figure 5 that the breaking load results in production direction were slightly higher than the results in the width direction. This was

The effect of the collector vacuum on the fibre diameter was found to be statistically significant. As it can be seen in Table 16, the fibre diameter slightly increased from 6,89 m to 7,15 m, when the collector vacuum increased from 15% to 30%. The reason of this increase might be the increasing pressure on the fibres. It can also be seen in Figure 4 and Table 15 that the fibre diameter did not change significantly with an increase in the collector vacuum from 30% to 60%. The highest results were obtained with 60% as 7,345 m, whereas

**Subset** 

**Pressure Fibre Diameter** 

**1 2** 

the lowest values were obtained with 15% as 6,900 m.

**Collector** 

Alpha = 0,05

on to the fibre diameter

by the extruder pressure.

Extruder Pressure

Fibre Diameter

**3.5 Tensile properties** 

width direction.

pressure on to the fibre diameter

**Vacuum N** 

**Correlations Extruder** 

\*\*. Correlation is significant at the 0.01 level (2-tailed).

15 45 6,900

30 45 7,159 60 45 7,345 Sig. 1,000 ,140

Table 16. Student-Newman-Keuls test results related with the effect of the collector vacuum

Table 17 shows the correlation between the extruder pressure and the fibre diameter. As it can be seen in the table, the correlation was not found to be statistically significant, so the fibre diameter of the meltblown nonwovens investigated in this study were not influenced

> Pearson Correlation 1 ,025 Sig. (2-tailed) ,769 N 135 135

Pearson Correlation ,025 1

N 135 135

Sig. (2-tailed) ,769

Table 17. 2-Tailed Pearson Correlation test results related with the effect of the extruder

Breaking load and % elongation were investigated to evaluate the tensile properties of the meltblown nonwovens. The results of the measurements have shown that the breaking load and the elongation were significantly affected by the collector drum speed, collector vacuum, die air pressure and extruder pressure in production direction, where a the extruder pressure did not appear to be a significant factor for the tensile properties in the

Figure 5 shows the breaking load values of the polypropylene meltblown nonwovens in production and width directions. It can be seen in Figure 5 that the breaking load results in production direction were slightly higher than the results in the width direction. This was because orientation of the fibre were more towards the production direction around the collector drum and therefore the strength was more enhanced in this direction.

Fig. 5. Breaking load values of polypropylene meltblown nonwovens

Figure 6 shows the elongation values in the production and the width directions. As it can be seen in Figure 6, the elongation results in production direction were slightly lower than the results in the width direction. In general, the elongation decreased with increasing breaking load.

Fig. 6. Elongation values of polypropylene meltblown nonwovens

Investigation of the Production Parameters and

**Collector Drum Speed N**

Alpha = 0,05

**Collector Drum Speed N** 

Alpha = 0,05

production direction and as 2,212 N in the width direction.

20 45 3,787 2,212

speed on to the breaking load in the production and width directions

direction and as 37,675% in the width direction.

**Subset (production direction)** 

10 45 14,952 20 45 37,675 20 45 18,355 10 45 38,199

speed on to the elongation in the production direction and width directions.

30 45 19,780 30 45 50,539 Sig. 1,000 ,185 Sig. ,656 1,000

Table 21. Student-Newman-Kleus test results related with the effect of the collector drum

30 45 4,400 3,254

10 45 12,408 7,211 Sig. 1,000 1,000 1,000 1,000 1,000 1,000

Table 20. Student-Newman-Kleus test results related with the effect of the collector drum

The effect of the collector drum speed on the elongation can be seen in Figure 6 and Table 21. The increase in collector drum speed caused an increase in the elongation both in the production and width directions, due to the decreasing basis weight and breaking load. In the production direction significantly lower elongation results were obtained with 10 ft/min compared to the other drum speeds. The difference between the results obtained with 20 ft/min and 30 ft/min were not found to be statistically significant. In the width direction significantly higher elongation results were obtained with 30 ft/min compared to the other drum speeds, whereas the difference between the results obtained with 10 ft/min and 20 ft/min were not found to be statistically significant. The highest values were obtained with 30 ft/min as 19,780% in the production direction and as 50,539% in the width direction, whereas the lowest values were obtained with 10 ft/min as 14,952% in the production

> **Collector Drum Speed N**

**1 2 1 2** 

**Subset (width direction)** 

Physical Characteristics of Polypropylene Meltblown Nonwovens 259

Table 20 shows the effect of collector drum speed on the breaking load in production and width directions. For both of the directions as a general trend the breaking load decreased with increasing collector drum speed, due to the decrease in the basis weight. It can be seen both in the production and the width directions that when the collector drum speed increased from 10 ft/min to 20 ft/min the breaking load decreased sharply and slightly increased again when the collector drum speed increased to 30 ft/min. The reason of this slight increase was thought to be the increase in fibre strength due to the drawing with higher speed. The highest values were obtained with 10 ft/min as 12,408 N in the production direction and as 7,211 N in the width direction, whereas the lowest values were obtained with 20 ft/min as 3,787 N in the

> **Subset (production direction) Subset (width direction) 1 2 3 1 2 3**

It can be seen in Figure 5 and Table 18 that the breaking load increased with increasing die air pressure both in the production and the width directions. This was caused by the increase in basis weight and thickness. The highest values were obtained with 8 psi as 9,904 N and the lowest values were obtained with 6 psi pressure as 3,859 N in the production direction, whereas highest values were obtained with 8 psi as 5,555 N and the lowest values were obtained with 6 psi pressure as 2,252 N in the width direction.


Table 18. Student-Newman-Keuls test results related with the effect of the die air pressure on to the breaking load in the production and width directions

Table 19 shows the effect of the die air pressure on elongation both in production and width directions. It can be seen in Table 19 and Figure 6 that elongation decreased with increasing die air pressure in the production direction, due to incresing breaking load. The difference between 6 psi and other die air pressures were found to cause a statistically significant difference in the elongation whereas the difference between 7 psi and 8 psi were not found to be statistically significant. In the width direction this trend was not valid; increasing pressure caused an increase in the elongation in this direction. The highest values were obtained with 6 psi as 20,640 % in the production direction and as 44,040 % in the width direction, whereas the lowest values were obtained with 8 psi as 15,310 % in the production direction and as 40,993 % in the width direction.


Table 19. Student-Newman-Keuls test results related with the effect of the die air pressure on to the elongation in the production direction and width directions.

It can be seen in Figure 5 and Table 18 that the breaking load increased with increasing die air pressure both in the production and the width directions. This was caused by the increase in basis weight and thickness. The highest values were obtained with 8 psi as 9,904 N and the lowest values were obtained with 6 psi pressure as 3,859 N in the production direction, whereas highest values were obtained with 8 psi as 5,555 N and the lowest values

**Subset (production direction) Subset (width direction)** 

**1 2 3 1 2 3** 

were obtained with 6 psi pressure as 2,252 N in the width direction.

6 45 3,859 2,252

on to the breaking load in the production and width directions

**Subset (production** 

**direction) Die Air** 

6 45 20,640 8 45 44,040 Sig. ,090 1,000 Sig. ,742 1,000

Table 19. Student-Newman-Keuls test results related with the effect of the die air pressure

8 45 15,310 6 45 40,993 7 45 17,137 7 45 41,380

on to the elongation in the production direction and width directions.

**Pressure N** 

**1 2 1 2** 

**Subset (width direction)** 

direction and as 40,993 % in the width direction.

7 45 6,832 4,870

8 45 9,904 5,555

Sig. 1,000 1,000 1,000 1,000 1,000 1,000

Table 18. Student-Newman-Keuls test results related with the effect of the die air pressure

Table 19 shows the effect of the die air pressure on elongation both in production and width directions. It can be seen in Table 19 and Figure 6 that elongation decreased with increasing die air pressure in the production direction, due to incresing breaking load. The difference between 6 psi and other die air pressures were found to cause a statistically significant difference in the elongation whereas the difference between 7 psi and 8 psi were not found to be statistically significant. In the width direction this trend was not valid; increasing pressure caused an increase in the elongation in this direction. The highest values were obtained with 6 psi as 20,640 % in the production direction and as 44,040 % in the width direction, whereas the lowest values were obtained with 8 psi as 15,310 % in the production

**Die Air Pressure N** 

Alpha = 0,05

**Die Air Pressure N** 

Alpha = 0,05

Table 20 shows the effect of collector drum speed on the breaking load in production and width directions. For both of the directions as a general trend the breaking load decreased with increasing collector drum speed, due to the decrease in the basis weight. It can be seen both in the production and the width directions that when the collector drum speed increased from 10 ft/min to 20 ft/min the breaking load decreased sharply and slightly increased again when the collector drum speed increased to 30 ft/min. The reason of this slight increase was thought to be the increase in fibre strength due to the drawing with higher speed. The highest values were obtained with 10 ft/min as 12,408 N in the production direction and as 7,211 N in the width direction, whereas the lowest values were obtained with 20 ft/min as 3,787 N in the production direction and as 2,212 N in the width direction.


Table 20. Student-Newman-Kleus test results related with the effect of the collector drum speed on to the breaking load in the production and width directions

The effect of the collector drum speed on the elongation can be seen in Figure 6 and Table 21. The increase in collector drum speed caused an increase in the elongation both in the production and width directions, due to the decreasing basis weight and breaking load. In the production direction significantly lower elongation results were obtained with 10 ft/min compared to the other drum speeds. The difference between the results obtained with 20 ft/min and 30 ft/min were not found to be statistically significant. In the width direction significantly higher elongation results were obtained with 30 ft/min compared to the other drum speeds, whereas the difference between the results obtained with 10 ft/min and 20 ft/min were not found to be statistically significant. The highest values were obtained with 30 ft/min as 19,780% in the production direction and as 50,539% in the width direction, whereas the lowest values were obtained with 10 ft/min as 14,952% in the production direction and as 37,675% in the width direction.


Alpha = 0,05

Table 21. Student-Newman-Kleus test results related with the effect of the collector drum speed on to the elongation in the production direction and width directions.

Investigation of the Production Parameters and

Extruder Pressure

Breaking Load

Extruder Pressure

Breaking Load

Extruder Pressure

Elongation

Extruder Pressure

Elongation

\*\*. Correlation is significant at the 0.01 level (2-tailed).

pressure on to the elongation in the production direction

\*\*. Correlation is significant at the 0.01 level (2-tailed).

**Production** 

**Width Direction** 

**Production** 

**Width Direction** 

**4. Conclusion** 

**Direction** 

**Direction** 

Physical Characteristics of Polypropylene Meltblown Nonwovens 261

Sig. (2-tailed) ,000

Sig. (2-tailed) ,979

Table 24. 2-Tailed Pearson Correlation test results related with the effect of the extruder

Table 25 shows the correlations between the extruder pressure and elongation of the meltblown webs in the production and the width directions. As it can be seen in the table, there was a significant negative correlation of 30,5% between these two factors in the production direction, which means that the elongation decreased with increasing extruder pressure in this direction. The correlations between the extruder pressure and elongation

Sig. (2-tailed) ,000

Sig. (2-tailed) ,153

The MB technique for making nonwoven products has been forecast in recent years as one of the fastest-growing in the nonwovens industry. With the current expansion and interest, a

Table 25. 2-Tailed Pearson Correlation test results related with the effect of the extruder

pressure on to the breaking load in the production and width directions

were not found to be statistically significant in the width direction.

**Correlations Extruder Pressure Breaking Load** 

Pearson Correlation ,333\*\* 1

Pearson Correlation 1 -,002 Sig. (2-tailed) ,979 N 135 135

Pearson Correlation -,002 1

**Correlations Extruder Pressure Breaking Load** 

Pearson Correlation -,305\*\* 1

Pearson Correlation 1 ,124 Sig. (2-tailed) ,153 N 135 135

Pearson Correlation ,124 1

N 135 135

N 135 135

Pearson Correlation 1 -,305\*\* Sig. (2-tailed) ,000 N 135 135

N 135 135

N 135 135

Pearson Correlation 1 ,333\*\* Sig. (2-tailed) ,000 N 135 135

The effect of the collector vacuum on the breaking load was shown in Table 22 and Figure 5. The breaking load increased with increasing vacuum in both directions, due to stronger bounding of the fibres in the web as a result of the increasing air pressure applied to the web by the vacuum. The highest values were obtained with 60% as 8,309 N in the production direction and as 5,654 N in the width direction, whereas the lowest values were obtained with 15% as 4,613 N in the production direction and as 2,994 N in the width direction.


Table 22. Student-Newman-Kleus test results related with the effect of the collector vacuum on to the breaking load in the production direction.

Table 23 shows the effect of collector vacuum on the elongation in the production and the width directions. As it can be seen in Figure 6 and Table 23, the elongation increased with increasing collector vacuum in both directions, even though there has been a slight decrease in 30% in the width direction. The highest values were obtained with 60% vacuum as 20,253% elongation in the production direction and as 49,139% elongation in the width direction, whereas the lowest values were obtained with 15% vacuum as 15,978% elongation in the production direction and as 37,181% elongation in the width direction.


Alpha = 0,05

Table 23. Student-Newman-Kleus test results related with the effect of the collector vacuum on to the elongation in the production direction and width directions

The correlation test results regarding the effect of the extruder pressure on the breaking load in the production and the width directions were presented in Table 24. As it can be seen in the table, there was a significant positive correlation of 33,3% between the extruder pressure and the breaking load in the production direction, whereas the correlation in the width direction was not found to be statistically significant. In other words, in the production direction the breaking load increased with increasing extruder pressure, but it did not have a significant effect in the width direction. Since the fibres were oriented more towards the production direction, the increase in the extruder pressure caused an increase in the fiber strength and it was reflected to the strength of the web in the production direction, but not in the width direction.

The effect of the collector vacuum on the breaking load was shown in Table 22 and Figure 5. The breaking load increased with increasing vacuum in both directions, due to stronger bounding of the fibres in the web as a result of the increasing air pressure applied to the web by the vacuum. The highest values were obtained with 60% as 8,309 N in the production direction and as 5,654 N in the width direction, whereas the lowest values were obtained with 15% as 4,613 N in the production direction and as 2,994 N in the width direction.

15 45 4,613 2,994

on to the breaking load in the production direction.

**Subset (production** 

30 45 7,673 4,029

in the production direction and as 37,181% elongation in the width direction.

**direction) Collector** 

30 45 16,856 10 45 40,094

15 45 15,978 20 45 37,181

on to the elongation in the production direction and width directions

60 45 8,309 5,654 Sig. 1,000 1,000 1,000 1,000 1,000 1,000

Table 22. Student-Newman-Kleus test results related with the effect of the collector vacuum

Table 23 shows the effect of collector vacuum on the elongation in the production and the width directions. As it can be seen in Figure 6 and Table 23, the elongation increased with increasing collector vacuum in both directions, even though there has been a slight decrease in 30% in the width direction. The highest values were obtained with 60% vacuum as 20,253% elongation in the production direction and as 49,139% elongation in the width direction, whereas the lowest values were obtained with 15% vacuum as 15,978% elongation

**Vacuum N** 

60 45 20,253 30 45 49,139 Sig. ,412 1,000 Sig. 1,000 1,000 1,000

Table 23. Student-Newman-Kleus test results related with the effect of the collector vacuum

The correlation test results regarding the effect of the extruder pressure on the breaking load in the production and the width directions were presented in Table 24. As it can be seen in the table, there was a significant positive correlation of 33,3% between the extruder pressure and the breaking load in the production direction, whereas the correlation in the width direction was not found to be statistically significant. In other words, in the production direction the breaking load increased with increasing extruder pressure, but it did not have a significant effect in the width direction. Since the fibres were oriented more towards the production direction, the increase in the extruder pressure caused an increase in the fiber strength and it was reflected to the strength of the web in the production direction, but not

**1 2 1 2 3** 

**Subset (width direction)** 

**Subset (production direction) Subset (width direction) 1 2 3 1 2 3** 

**Collector Vacuum N**

Alpha = 0,05

**Collector Vacuum N** 

Alpha = 0,05

in the width direction.


\*\*. Correlation is significant at the 0.01 level (2-tailed).

Table 24. 2-Tailed Pearson Correlation test results related with the effect of the extruder pressure on to the breaking load in the production and width directions

Table 25 shows the correlations between the extruder pressure and elongation of the meltblown webs in the production and the width directions. As it can be seen in the table, there was a significant negative correlation of 30,5% between these two factors in the production direction, which means that the elongation decreased with increasing extruder pressure in this direction. The correlations between the extruder pressure and elongation were not found to be statistically significant in the width direction.


\*\*. Correlation is significant at the 0.01 level (2-tailed).

Table 25. 2-Tailed Pearson Correlation test results related with the effect of the extruder pressure on to the elongation in the production direction
