Preventing Water-Induced Mechanical Deterioration of Cardboard by a Sequential Polymer Treatment

Abstract

Paperboards and corrugated cardboard are some of the most used products in packaging today. Because of their geometry, i.e., undulations, they are mechanically robust and can sustain a significant amount of weight. However, exposure to water or humidity is highly destructive toward cardboard mechanical properties. Water-soaked corrugated cardboard can easily collapse with irreversible shape distortions. Various treatments have been developed to render cardboard hydrophobic including wax layers and nanoparticle treatments. However, not all hydrophobic cardboard mechanical properties can necessarily withstand water immersion or high humidity. In this work, we utilize hydrolysis-resistant polyester-based thermoplastic polyurethane (TPU) to prevent mechanical deterioration of water-immersed and humidity-exposed cardboard. TPU-treated wet cardboard featured enhanced Young modulus, tensile stress, and elongation at break by 226%, 727%, and 116%, respectively, compared to plain wet cardboard. Results outperformed a similar treatment with a hydrophobic silicone resin indicating that a hydrophobic polymer is not essential for preventing mechanical deterioration of cardboard against water. The sequential treatment by these two polymers was also very effective in the wet case with 276% enhancement in Young’s modulus and 950% boost in tensile stress. The role of silicone resin in the sequential treatment was to form durable and stable hydrophobic surface properties on the cardboard.

Evaluation of Coatings to Improve the Durability and Water-Barrier Properties of Corrugated Cardboard

“…Furthermore, previous works [7] reported how fluorine-containing coatings provide one of the lowest free-surface energies. Instead, regarding the T-POL and K-POL coatings, their contact angle ranged between 104-114 • , which is consistent with other polymeric coatings [16,18]. Although SG provides lower wettability, hence the water droplets easily slip off the substrate, the CA values generally did not show a correlation with Cobb test performance (excluding UC samples).…”

“…Coatings can improve the corrugated cardboard water barrier and wet performance. Multiple works were done in the literature to improve corrugated cardboard water barrier properties [15][16][17][18][19][20]. The proposed solutions that were typically investigated used pigments and polymers.…”

The Evaluation of Agarose-Based Gel Systems for Surface Cleaning Albumen Prints vs the Conventional Water Treatment

“…The tensile strength of paper-based materials generally decreases when they are exposed to high humidity [76,77]. Water also causes the elongation of paper to decrease [78]. Organic solvents tend to swell cellulose less than water: ethanol (83%) and toluene (2%) [79].…”

An Experimental Study on the Performance of Corrugated Cardboard as a Sustainable Sound-Absorbing and Insulating Material

“…Corrugated cardboard can also be used as an interior building material and, when discarded, can be reused for pulp or paper [25]. Corrugated cardboard is known for its utility as a building material [25,26], and some studies have suggested the potential of hydrophobic treatment to avoid moisture absorption and further expand its versatility [27,28]. Moreover, it may act as a flame retardant, improving building safety [29].…”