Even though corrugated boards are the most common packaging materials for agricultural products, conventional corrugated boards are not able to maintain the freshness of agricultural products. In order to overcome the limitations of conventional corrugated boards, a new hybrid corrugated board (- composed of linerboard, a corrugating medium, and non-woven fabric-) was designed to possess antibacterial, high porous and shock-absorbing properties.
In this study, we developed new antibacterial materials and a new adhesive system and also compared the physical properties of non-woven fabric to those of the base papers of conventional corrugated boards as a first step toward manufacturing the hybrid corrugated board. The result was that in the linerboard that treated sulfur solution there appeared a high value of antibacterial activity and fungal resistance. It was identified that sulfur solution has effective antibacterial properties. We found that the non-woven fabric, which had relatively high elongation, was applicable in the corrugated board process, and that the manufacturing conditions must be controlled in order to prevent the break of the non-woven fabric. The mixture of starch and styrene-butadiene (SB) latex showed high adhesive strength, but the addition level of SB latex should not exceed 20% in starch solution.
Based on experimental data, the prototypes of functional hybrid corrugated boards were manufactured and their physical properties and functionalities, including antibacterial property, the freshness maintenance of sweet persimmon, and shock-absorbing property were measured. Consequently, The functional hybrid corrugated board could be manufactured in the actual process with linerboards, non-woven fabrics, and other materials without any troubles, and was strong enough to be used as a packaging box for agricultural products. The antibacterial property of the hybrid corrugated board showed a value high enough to eliminate bacteria, which could deteriorate the sweet persimmons. Based on appearance observations, weight loss and firmness measurements, the freshness of sweet persimmons in the functional hybrid corrugated board was maintained better than it was in the conventional corrugated board. In drop and shaking tests, it was certain that the hybrid corrugated board showed the better shock-absorbing property than the conventional corrugated board.