Adhesion improvement of LLDPE/PA tubular foil used as sausage casing after a very short atmospheric-pressure roll-to-roll plasma treatment
| Authors | |
|---|---|
| Year of publication | 2022 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | This research aimed to optimize the diffuse coplanar surface barrier discharge (DCSBD) roll-to-roll (R2R) treatment of multi-layer tubular foil as a very efficient plasma technology using several types of rollers differing in material resistance. Multi-layer tubular foils are commonly utilized in the meat processing industry as sausage or ham casings. The effect of ambient air plasma generated by coplanar and volume dielectric barrier discharge, so-called “industrial corona”, on the surface characteristics of tubular foil formed from the outside by polyamide and from the inner side by linear low-density polyethylene (LLDPE) was studied. During the roll-to-roll treatment, the plasma acts from outside of the LLDPE/PA tubular foil, whereas the inside LLDPE surface is affected by plasma as well in dependence on the material of the roller used in combination with the DCSBD plasma unit. Various rollers differing in their electrical properties (conductivity, resistance) were utilized for experiments and compared. Based on these findings, the utility model “Device for plasma treatment of tubular foils” focused on DCSBD plasma in the roll-to-roll arrangement was registered [1]. It has been experimentally verified that a non-conductive roller constructed from plastic does not allow the surface discharge to be superimposed by microfilaments generated perpendicular to the film surface. This finding clarified the different effects of plasma treatment achieved using plastic and metal-rubber roller on the surface properties of LLDPE foil. Applied exposure times of DCSBD treatment were in the range of 0.5–2 seconds. Evident wettability improvement of LLDPE foil surface after the plasma treatment was observed with the naked eye, while the pristine LLDPE foil surface repelled water solution of methylene blue used to visualize the plasma effect. The desired increase in peel resistance in the case of 0.5 s exposure time when comparing plastic and metal-rubber roller was three times higher for the second one. Peel resistance of untreated LLDPE foil was so low that it was unmeasurable. Best results were obtained for 2 s plasma exposure, where the peel resistance achieved using the metal-rubber roller was 31 % higher than for the plastic roller. The industrial corona treatment of the LLDPE/PA tubular foil was less effective compared to the DCSBD treatment under the same working conditions (exposure time, square power density of plasma). DCSBD plasma treatment in the roll-to-roll arrangement can improve the adhesion properties of the outer (better printability, dyeability) and the inner surface (enhanced adhesion of the meat mixture) of LLDPE/PA tubular foil simultaneously in combination with the appropriate roller. |
| Related projects: |