Paper pots are widely used in vegetable transplantation in agricultural cultivation and must have sufficient strength to withstand separation and mechanical works that occur during transplantation. Therefore, biodegradation owing to soil microorganisms during seedling growth must be inhibited. In this study, hydrolysis owing to cellulase was inhibited by applying an arbitray mixture of citric acid and sodium hypophosphite to paper and then heat-treating it. This inhibition of hydrolysis resulted from the formation of a cross-linked structure between the cellulose hydroxyl groups of the paper (wood pulp) and citric acid through ester bonds. The decay-resistant paper produced by this method will be useful as a base paper for the production of paper pots.

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In this review, three technical processes were proposed for constructing a next-generation textile laundry system. The detergency experiments using artificially soiled fabrics and mechanical action test pieces were performed using a beaker-level equipment and a horizontal drum-type washer. The soiled fabrics were prepared using mainly three polyester fabrics with different structure as substrates, and carbon black, red clay, oleic acid, or stearic acid as a model contaminant. The detergency was evaluated from the change in the Kubelka–Munk function value of artificially soiled fabrics and the original fabric due to washing. The effects of artificially soiled fabrics by atmospheric pressure plasma jet treatment before washing, application of ultrasound as a mechanical action during washing, and rinsing by the fine bubble water after washing on detergency were discussed. Conclusively, combination of three techniques enabled particulate and oily soil to remove from polyester fabric at a level comparable to a drum-type washer with little fabric damage.

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