The Efficiency Evaluation of the Reactive Extrusion Process for Polyethylene Terephthalate (PET). Monitoring of the Industrial Foil Manufacturing Process by In-Line Rheological Measurements

Abstract

The main topic of the presented work is the evaluation of the in-line viscometer (VIS) operation installed on the industrial line for polyethylene terephthalate (PET) foil production. The tests were performed during the regular operation of the machine, which results from the need to maintain production continuity. Polymer viscosity control is of particular importance in the production of degradable materials and recycled polymers. The processing of PET film is, therefore, a particularly difficult issue due to the presence of both of these problems at the same time. The conducted research had a two-pronged character: assessment of the correct operation of the viscosity measurement system and testing of the effectiveness of reactive additives during the extrusion process. Measurements were carried out with the use of several types of input materials, including recycled blends. The key tests were carried out with the addition of viscosity modifiers. Measurements conducted during the extrusion process confirmed the effectiveness and high sensitivity of the in-line system (VIS), while clear changes in the polymer flow characteristics were observed only after the addition of chain extenders. The in-line measurements revealed that the addition of 1% of the reactive compound increased the viscosity from the initial 150 Pa∙s to over 350 Pa∙s. The most significant increase in viscosity for the additive based on pyromellitic dianhydride (PMDA) confirms the effectiveness of the reactive extrusion method and the suitability of the used measuring. During further analysis, the obtained films were also tested. The results showed no negative effects of the reactive extrusion on the mechanical performance of the foil; however, for recycled materials, the average values of tensile strength and elongation at break have deteriorated. A positive aspect of the use of reactive additives was the greater uniformity of mechanical properties. For some materials, there was a significant increase in the haze factor (transparency), which should be considered a disadvantage.

Utilization of Multilayered Polyethylene Terephthalate (PET)-Based Film Packaging Waste Using Reactive Compatibilizers and Impact Modifier

“…However, it should be emphasized that in the last decade, the issue of recycling polymer products has begun to be treated more seriously by many packaging manufacturers. Among all varieties of packaging materials, particularly effective recycling systems have been implemented for PET-based materials (polyethylene terephthalate) [7][8][9][10]. This is particularly the case due to the characteristics of PET used in the packaging industry, where transparent products with a very low content of fillers, dyes, or modifiers predominate.…”

Mechanical behavior analysis of polypropylene composites with waste PET felt fibers

“…The appearance of the 2915 cm −1 ‐peak in the FTIR spectrum of the PP–PET composite indicates good interaction between the two materials 26,27 . Furthermore, the spectral peaks of the PP–PET sample showed the characteristic absorption bands of PP, including 2917 and 2838 cm −1 for the asymmetric stretching of –CH 2 and –CH 3 , respectively, and the sharp peaks at 1453 and 1376 cm −1 attributed to –CH 2 – and –CH 3 bending, respectively 14 further supports the well‐bonded interactions between PET ff /PP. The CH 2 group in the PP backbone connected to the CH 3 group of the PET backbone through van derwalls forces.…”

“…PP and PET fiber composites can be used in a wide range of applications because of their desirable properties, such as high strength, low density, and resistance to moisture and chemicals. Increasingly, researchers are exploring the use of PP and PET in self‐reinforced polymer composites, which have the potential to outperform traditional composites 14,15 . During PET fiber orientation, the folded chain crystal lamellae undergo rotation, breakup, unfolding, and ultimately form aligned chain crystals, resulting in an enhancement of mechanical properties 16 .…”

“…Increasingly, researchers are exploring the use of PP and PET in selfreinforced polymer composites, which have the potential to outperform traditional composites. 14,15 During PET fiber orientation, the folded chain crystal lamellae undergo rotation, breakup, unfolding, and ultimately form aligned chain crystals, resulting in an enhancement of mechanical properties. 16 The study tensile modulus of the over-molded composites was significantly higher than that of the self-reinforced PET sheets alone.…”

The Use of Recycled Polymers for the Preparation of Self-Reinforced Composites by the Overmolding Technique: Materials Performance Evaluation

“…The main reason for that is the lack of fillers, pigments, or other additives used during the manufacturing of PET-based products, like bottles, foils, and other types of packaging. The research on the use of recycled PET (or rPET) as a component of technical blends has been known for many years, also on an industrial scale [37][38][39][40]; however, a literature review shows very few examples where the polymer system also contains a recycled PC component [41,42]. The obvious reason for that is the high susceptibility of PC to hydrolytic degradation.…”