Application of corona discharge to modify the surface layer of polyester textiles

Abstract

Zastosowanie wy³adowañ koronowych do modyfikowania warstwy wierzchniej w³ókienniczych materia³ów poliestrowychStreszczenie -Przedstawiono wyniki badañ oddzia³ywania wy³adowañ koronowych, generowanych przez skonstruowany przez nas zestaw urz¹dzeñ (PZU) do modyfikowania warstwy wierzchniej w³ókienniczych materia³ów polimerowych, na w³aoeciwooeci warstwy wierzchniej tkaniny poliestrowej (PET). Oceniono wp³yw jednostkowej energii (Ej) tych wy³adowañ na k¹t zwil¿ania i swobodn¹ energiê powierzchniow¹, w³oskowatooeae, wybarwialnooeae barwnikiem testowym, ilooeae grup kwasowych i zawartooeae tlenu w warstwie wierzchniej oraz na zmiany struktury geometrycznej powierzchni w³ókien badanego materia³u. Stwierdzono, ¿e wy³adowania koronowe pochodz¹ce z PZU powoduj¹ znaczn¹ poprawê zwil¿alnooeci modyfikowanej tkaniny, zwiêkszenie swobodnej energii powierzchniowej, a zw³aszcza jej sk³adowej polarnej oraz wzrost w³oskowatooeci. Wy³adowania te stymuluj¹ równie¿ powstawanie grup kwasowych oraz zwiêkszaj¹ zawartooeae tlenu w warstwie wierzchniej, a tak¿e wp³ywaj¹ na wyraŸne rozwiniêcie powierzchni w³aoeciwej w³ókien, nie zmniejszaj¹c przy tym w istotnym stopniu ich wytrzyma³ooeci mechanicznej. Badania potwierdzi³y s³usznooeae przyjêtej koncepcji konstrukcyjnej i funkcjonalnej zestawu urz¹dzeñ do wy³adowañ koronowych (PZU) umo¿li-wiaj¹cej uzyskanie efektów modyfikowania bez istotnych uszkodzeñ w³ókien modyfikowanego ma-teria³u. S³owa kluczowe: w³ókiennicze materia³y polimerowe, modyfikowanie warstwy wierzchniej, wy³adowania koronowe, urz¹dzenia do wy³adowañ koronowych, w³aoeciwooeci. APPLICATION OF CORONA DISCHARGE TO MODIFY THE SURFACE LAYER OF POLYESTER TEXTILESSummary -The results of investigations of the effects of corona discharge, generated by a tool set (PZU) constructed by us to modify the surface layers of polymeric textiles, on the properties of surface layer of polyester (PET) fabric are presented. The effects of unit energy (Ej) of corona discharge on the following factors were evaluated: contact angle and surface free energy (Table 1), capillarity (Fig. 1), dyeability with a test dye ( Table 2, Fig. 2), acidic groups' amount ( Fig. 3), oxygen content at a surface layer ( Fig. 4) and changes of geometrical structures of the fibers' surfaces of a material tested (Fig. 5). It was found that corona discharge coming from PZU caused a significant improvement in wettability, increase in surface free energy, especially its polar component, and growth in capillarity of the fabric modified. The corona discharge stimulated also the formation of acidic groups and increase in oxygen content in the surface layer. It also caused a significant specific surface development of a fiber without visible deterioration of mechanical strength. The investigations results confirmed that the design and functional quality of our corona discharge set were appropriate and the set made possible the modification of the fibers without substantial damages of the fibers of material modified.

Surface energy of corona treated PP, PE and PET films, its alteration as function of storage time and the effect of various corona dosages on their bond strength after lamination

“…The maximum value of PE‐LD film with 43 mN/m is below the value of 46 mN/m stated by Földes et al . Similarly, the maximum surface energy of 52 mN/m for PET‐BO is below the value of 57 mN/m reported for PET . The values for PE‐LD are higher than for PP‐BO.…”

Corona Treatment

“…Value of activation energy and surface thickness of the charge accumulated in the upper layer are correlated with each other (Brzezi nski et al, 2009;Czaja, 2008). Lubricants and other additives migrate to the upper layer of the polymer and prevent from treatment of the material.…”

“…If it is not bound with the substrate permanently, then it may cause problems with adhesion and lead to problems with blocking during printing of the material (Brzezi nski et al, 2009;Chan, 1999;Kusano, 2014;Stepczy nska & _ Zenkiewicz, 2014;Tuominen et al, 2010). Kinetic energy of electrons, which emerge during discharge in electrode space, amounts from few to several electron-volts.…”

“…It may also be obtained by using neutral gases during the process (Stepczy nska & _ Zenkiewicz, 2014). The increase in electron density and the curvature of the electrode's wire cause the increase in density of positive ions (Brzezi nski et al, 2009;Kim, 1996;Kulumbaev et al, 2011;Ozdemir et al, 1999;Skalny, Luknárová, & Dindo sová, 1988;Sparavigna & Wolf, 2006;Stasyuk & Pyatetskii, 1993;_ Zenkiewicz & Lutomirski, 2001). Therefore, in order to obtain a higher level of activation, one should reduce the speed of the process (Stasyuk & Pyatetskii, 1993).…”

“…oxidation of upper layer, emerging of polar groups on the surface; cleaning the surface of the material and improvement of its roughness, modification of the geometric structure (achieved by the highest E j values); development of proper surface without changing mechanical properties of the whole material; preparation of polymer for graft polymerization and possible initiation of the process; examination of accelerated aging of the material; sterilization and disinfection of the packages and medical materials under the impact of ozone; preparation of intermediate product used for producing the final material: for example, fibers used in composites improving the compatibility between compounds (integration between the fiber and polymer matrix) and mechanical and thermal properties of composite; cleaning the waste gases (Brzezi nski et al, 2009;Ozdemir, Yurteri & Sadikoglu, 1999;Pekárek, 2010;Ragoubi et al, 2012;Sparavigna & Wolf, 2006;Stepczy nska, 2014;_ Zenkiewicz, 2008).…”