Page 527 - Handbook of Properties of Textile and Technical Fibres

500 Handbook of Properties of Textile and Technical Fibres

Box plot (flex fatigue)
1.4e6

1.2e6
1e6

8e5

6e5

4e5
Nonoutlier max
2e5
Nonoutlier min
75%
0 25%
Median
Extremes
–2e5
A B C D E Outliers
Figure 13.38 Box plot summarizing FC data for all samples (FC are on the y-axis) (Militký
et al., 2011).

13.6 Conclusions

In this review the basic information about chemistry, fabrication technology and struc-
ture of PET, and modified PET fibers are collected. The main approaches to the
modeling of tensile behavior of polymeric fibers focused on PET are presented.
Despite the fact that PET and modified PET fibers have been widely investigated
there are still no fully described phenomena for the prediction of the mechanical
behavior and tensile failure based on the structure or manufacturing parameters.
One main reason is the complex character of changes during fiber manufacturing
and modifications of structure during influence of stress field, temperature, time,
and environmental factors. There exists a continuous effort for the investigation of
structural changes of fibers online but the information data are only indirect and global.
In fact, most of mechanical and failure properties are dependent on the local structure
and therefore the use of statistically averaged information is speculative. A deeper un-
derstanding can be obtained from the distribution of data or replacing the mean values
by suitable quantities (Meloun et al., 1992).

References

Ahzi S, Makradi A, Gregory RV, Edi DD: Modeling of deformation behavior and strain induced
crystallization in Poly (ethylene terephthalate) above the glass transition temperature, Mech
Mater 35:1139e1148, 2003.
Aizenshtein EM: World production and consumption of polyester fibers and yarns, Fibre Chem
39:355e362, 2007.