I am interested to characterize one layer of co-extruded polymer film at different stages of thermal degradation; heat sealing.
which characterization methods can show the damage on the film structure ? when the film is overheated/burned by the sealing process, does it impact the structure?
Thanks in advance for your feedback
Typical method for assessing thermal degradation of plastic films include tensile testing, FTIR (transmission and ATR from both sides), OIT (oxygen index testing) by DSC. With some consideration these methods can be used also for coextruded (multilayer) films. Optical microscopy of cross sections may also be useful. In practical applications, however, the best is always to measure the target property (e.g. sealing in your case) after various aging times.
Hi
I think you can find the method for characterization of the polymer film structure in " Characterization of amorphous and nanocrystalline carbon films " paper which was published by Paul K. Chu.
Hi,
AFM or other microscopes can be applicable to probe the structural damage of one given layer in your layered systems subjected to thermal or mechanical deformation. X-ray tests might also work there. (Ref. Macromol. Symp. 2010, 294-I, 33–44)
When the layered films are overheated, layer rupture/breakup or dewetting might occur accordingly. Nevertheless, we need to bear in mind that the presence of layer rupture or not should also depend on the properties of constituent polymers, and their interactions, physico-chemical... (Ref. Polymer, 2016, 90, 156-164; Polymer, 2005, 46, 3043–3055; PRL, 2001, 86, 24)
Typical method for assessing thermal degradation of plastic films include tensile testing, FTIR (transmission and ATR from both sides), OIT (oxygen index testing) by DSC. With some consideration these methods can be used also for coextruded (multilayer) films. Optical microscopy of cross sections may also be useful. In practical applications, however, the best is always to measure the target property (e.g. sealing in your case) after various aging times.
Dear Imane, FT-IR technique with ATR accessory before and After sealing can be ok To study surface modification. Trasmittance FT-IR can be done to study the full multilayer ( if it is transparent and not too much thick). Regards
Dear Imane,
I don’t know the details regarding your experimental study, but I believe that could be nice to have comparative information about the changes of considered polymer (layer) in the different steps of processing. In some cases implying small number of layers, using some experimental artefacts, you can separate the component layers. Then, it is possible to perform their analyses following the different methods indicated by other RG colleagues. But maybe here there is not this possibility…
However, I assume that the wrong welding parameters could lead to polymer degradation (is it possible to check the decrease of molecular weights?), changes in the morphology, thermal, and mechanical properties of films, cracks, bubbles, etc. Please consider some information from literature for eventually help and for some new ideas.
Good luck in your study and best regards,
Marius
Hernandez-Izquierdo, et al., (2009), Thermal transitions and heat-sealing of glycerol-plasticized whey protein films. Packag. Technol. Sci., 22: 255–260. doi: 10.1002/pts.847
Beatriz Ribeiro Nogueira et al., The influence of electron-beam irradiation on some mechanical properties of commercial multilayer flexible packaging materials, July 2009, Radiation Physics and Chemistry 78(s 7–8); DOI10.1016/j.radphyschem.2009.03.041
https://www.ipen.br/biblioteca/2009/14934.pdf
Heat Sealing Fundamentals, Testing, and Numerical Modeling
https://web.wpi.edu/Pubs/E-project/Available/E-project-042915-173630/unrestricted/Heat_Sealing.pdf
Y. Hashimoto et al., Effect of heat sealing pressure on mechanical properties and molecular structure at heat-sealed parts of poly (Lactic Acid) plastic film, January 2012, Journal of Packaging Science and Technology 21(2):115-123
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