journal article·2025-07-24

Adhesion with purpose: The value of primers in sustainable flexible packaging

YONG ZHENG

TAPPI Journal· Volume 24· Issue 7
Publisher page

Abstract

Primers play a crucial role in flexible packaging by providing adhesion, enhancing performance, and improving the overall quality of packaging structures. As the packaging industry shifts towards more sustainable solutions, it brings new challenges for meeting adhesion requirements. Different types of sustainable materials, with their complicated physical and chemical properties, usually result in poor adhesion in extrusion coating or extrusion lamination, whether this is due to fast crystallization, secondary crystallization, low processing temperature, lack of functional groups, or a combination thereof. Water-based primers ensure that these innovations meet both functional and environmental standards for the packaging of tomorrow. Conventional water-based primers, including polyethyleneimine (PEI) and ethylene acrylic acid (EAA), offer significant advantages in sustainable packaging design by chemically modifying the surface of the substrate to enhance adhesion. In this study, we will discuss adhesion issues in three case studies involving sustainable packaging materials: (1) extrusion coating of polyvinyl alcohol (PVOH) on paper; (2) extrusion lamination of paper and metallized film with starch biopolymer; and (3) extrusion coating of polyhydroxyalkanoates (PHA) on paper. These cases represent three adhesion challenges related to sustainable materials, namely fast crystallization rate, low processing temperature, and secondary crystallization. A three-step adhesion improvement procedure was employed to identify the proper primer in each case study. This procedure included a wetting-out test with primer, an adhesion test, and an extrusion test with priming. In our results, strong fiber tearing or destructive bonds were achieved in each case with the help of water-based primers. These results demonstrate the value of water-based primers in enabling the transition to more sustainable packaging structures without compromising performance.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Advanced Sensor and Energy Harvesting Materials · Nanocomposite Films for Food Packaging · biodegradable polymer synthesis and properties

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (14)

Show source-provided references
1. Wu, F., Misra, M., and Monhanty, A.K., Prog. Polym. Sci. 117: 101395(2021). https://doi.org/10.1016/j.progpolymsci.2021.101395.10.1016/j.progpolymsci.2021.101395 ↗
2. Bohlmann, G.M., Environ. Prog. 23(4): 342(2024). https://doi.org/10.1002/ep.10053.10.1002/ep.10053 ↗
3. Rydz, J., Musioł, M., Zawidlak-Węgrzyńska, B., et al., “Present and future of biodegradable polymers for food packaging applications,” in Handbook of Food Bioengineering, Biopolymers for Food Design (A.M. Grumezescu and A.M. Holban, Eds.), Academic Press, Cambridge, MA, USA, 2018, Chap. 14, pp. 431-467.https://doi.org/10.1016/B978-0-12-811449-0.00014-1.10.1016/b978-0-12-811449-0.00014-1 ↗
4. Siracusa, V., Rocculi, P., Romani, S., et al., Trends Food Sci. Technol. 19(12): 634(2008). https://doi.org/10.1016/j.tifs.2008.07.003 .10.1016/j.tifs.2008.07.003 ↗
5. Bentley, D.J. and Singer, F.M., “Chemical primers for extrusion coating,” in Extrusion Coating Manual (W. Durling, Ed.), 5th edn., TAPPI Press, Peachtree Corners, GA, USA, 2017, Chap. 4, Sect. 18.
6. Twomey, J., Pap. Synth. Conf., Proc., TAPPI Press, Atlanta, 1975, p.331.
7. Lee, L.H., Ed., Adhesive Bonding, 1st edn., Plenum Publishing, New York, 1991.10.1007/978-1-4757-9006-1_1 ↗
8. Zheng, Y. and Meadows, D., “Extrusion coating with PVOH to produce high-barrier paper-based packaging,” TAPPI Flexpack PLACE Conf., TAPPI Press, Peachtree Corners, GA, USA, 2024.
9. Meadows, D., “Using Aquapak’s Hydropol polymer in extrusion coating for functional packaging design and multiple end of life options,” 18th Bienn. TAPPI Eur. PLACE Conf., TAPPI Press, Peachtree Corners, GA, USA, 2022.
10. Chacon, D., “Value chain led product innovation,” TAPPI Flexpack PLACE Conf., TAPPI Press, Peachtree Corners, GA, USA, 2024.
11. Choi, S., Hwang, D.K., and Lee, H.S., Carbon Lett. 14(4): 282(2014). https://doi.org/10.5714/CL.2014.15.4.282.10.5714/CL.2014.15.4.282 ↗
12. Hamouda, S.B., Nguyen, Q.T., Langevin, D., et al., C. R. Chim. 13(3): 372(2010). https://doi.org/10.1016/j.crci.2009.10.009.10.1016/j.crci.2009.10.009 ↗
13. Foederer, B.M. and Morris, B.A., “Use of IR technology to model temperature loss in the air gap,” TAPPI PLACE Conf., TAPPI Press, Peachtree Corners, GA, USA, 2014.
14. Eesaee, M., Ghassemi, P., Nguyen, D.D., et al., Biochem. Eng. J. 187: 108588(2022). https://doi.org/10.1016/j.bej.2022.108588.10.1016/j.bej.2022.108588 ↗