Influence of the calender temperature on the crystallization behaviors of polylactide spun-bonded non-woven fabrics

Abstract

In this paper the influence of calender temperature on the crystallization behavior of polylactide (PLA) non-woven fabrics during their manufacturing by the spun-bonding technique is described. Non-woven samples were studied by wide-angle X-ray diffraction, differential scanning calorimetry and birefringence. In addition, physical–mechanical properties of the non-woven fabrics were determined. The results are discussed in terms of structural changes of PLA and meso-phase content during the calendering process in the temperature range 70–130℃. The rebuilding of the supermolecular structure of the investigated samples of PLA fabrics under the influence of increasing calender temperature is observed in terms of the disorder-to-order phase transition (ά to α form) during heating around 110℃, and increased degree of crystallinity up to 100℃. The presented structural rebuild of PLA explains observed changes of physical–mechanical properties of the non-woven fabrics obtained at different calendering temperatures. During calendering above 100℃, thermal degradation of PLA occurs at the point of contact between the non-woven fabrics and the calender rollers.

Fabrication of Plga/Hap and Plga/Phb/Hap Fibrous Nanocomposite Materials for Osseous Tissue Regeneration

“…According to the Hindelen and Lorentz method, the experimental data were approximated by theoretical crystalline, mesomorphous peaks and an amorphous halo as Gaussian and Lorentzian functions using the WAXS program. The shapes and 2θ position of the crystalline, amorphous peaks and the mesomorphous halo were selected according to Stoclet et al [46,47].…”

Investigation on the Melt Processing of Biodegradable Aliphatic-Aromatic Polyester into Fibrous Products

“…The anisotropy of tenacity of nonwoven calendered at a temperature in the range of 50 -65 °C probably ensues from thermal degradation of the nonwoven at the point of contact with the calender. The same proceeds in the nonwoven made of polylactide [21].…”

Effect of processing variables on the thermal and physical properties of poly(L-lactide) spun bond fabrics

“…The obtained results agree with those presented in a previous report, confirming the crystallization of PLA in the form below the critical temperature of 100 C and the formation of crystals at higher temperatures. 26 It is worth noting that the dspacing depends insignificantly on the take-up velocity up to 1257 m/min. …”

“…[21][22][23][24] Therefore, it is important to analyze the molecular ordering and the formation of the or forms of commercially available PLA during technological processes, 25 for example, the production of spun-bonded non-woven fabrics. 26 Previously, only the influence of the calender temperature on the meso and crystalline phase formation and an estimation of the critical temperature of the disorder-to-order transition were presented. 26 A more direct analysis of the technological process of spunbonded non-woven production shows that other factors besides the calender temperature may affect the molecular ordering and crystallization.…”

“…26 Previously, only the influence of the calender temperature on the meso and crystalline phase formation and an estimation of the critical temperature of the disorder-to-order transition were presented. 26 A more direct analysis of the technological process of spunbonded non-woven production shows that other factors besides the calender temperature may affect the molecular ordering and crystallization. The present study focused on the influence of different technological conditions on the microstructure of PLA, especially the combined effect of the different pressures in the downstream spinning block resulting from the different air attenuator widths and the calender temperatures.…”