Utilization of recycled pulp from used beverage cartons and bio-based PLA for disposable oil-absorbing pads

Abstract

The increasing consumption of milk, juice, and other beverages has led to a rise in residual waste from beverage cartons. This study focuses on developing oil-absorbing pads using recycled pulp from beverage cartons as the core layer and non-woven polylactic acid (PLA) as the face layer. Recycled pulp was ground at various spinning times, producing rough, intermediate, and ultrafine forms. These pulps were treated with JAN (Japan) and GER (Germany) silane solutions at concentrations of 1, 2, 3, 5, and 10 wt%. Non-woven PLA was fabricated via the melt-blown process at screw speeds of 0.5 and 13 rpm, resulting in large and ultrafine PLA mats. Oil absorbency tests were conducted at various weight ratios of recycled pulp to non-woven PLA (100:0 to 0:100). Although untreated ultrafine pulp was unable to form sheets on its own, it exhibited the highest absorption capacity, reaching up to 19.5 g/g. Untreated pulp consistently absorbed more oil than treated variants. Consequently, ultrafine untreated pulp was used for further testing in mixed ratios with PLA. The results showed a decrease in oil absorbency with increasing PLA content. Among the PLA samples, the large non-woven PLA achieved the highest absorption capacity of 19.8 g/g and was selected for the pad's face layer. The final oil-absorbing pads, sized 10 cm × 10 cm, were fabricated using ultrasonic welding to seal the layers. The developed prototype incorporates recycled and biodegradable materials, offering a sustainable solution for oil absorption applications aligned with environmental goals.