Currently, cardboard (paperboard) is the most eco-friendly option for express packaging due to its numerous benefits, such as affordability, ease of recycling, widespread availability, and environmental sustainability. It is used to package a diverse array of consumer products, such as food, beverages, cosmetics, pharmaceuticals, and electronics. However, its lifespan is reduced because of its tendency to absorb water or moisture. This study enhances the water resistance of cardboard by applying a superhydrophobic coating using OTS (octadecyltrichlorosilane) that shields it from water and moisture. The treated cardboard demonstrates outstanding water-repellent properties, with a static water contact angle exceeding 150° and a sliding angle below 10°. The performance of the coated surfaces is evaluated under various conditions, including high temperatures, exposure to acidic and alkaline solutions, and mechanical tests (surface bending, water jet, tape peeling, and abrasion with sandpaper). The modified surface also demonstrated self-cleaning, stain-resistant, and anti-termite properties. Self-cleaning and stain resistance were verified using dye powder, while termite resistance was confirmed through exposure in a termite-prone environment. The coated paperboard’s suitability for food and beverage packaging was validated by storing sugar and tea. After one week of sugar storage, the coated sample showed only a 5% weight increase compared to a 200% gain for uncoated paperboard. In the tea storage test, the uncoated box absorbed 10% of the liquid within one minute, while the coated one showed negligible absorption (~ 0%). Leak-proof performance was further confirmed by immersing dye-filled boxes in water. The exceptional durability and water resistance of the coated cardboard make it highly promising for both domestic and industrial food packaging applications.
Pandit et al. (Thu,) studied this question.