An optimum mixture of virgin rice straw pulp and recycled old newsprint (ONP) pulp and their antimicrobial activity

Recycled fibres are important sources for paperboard industry. There are various approaches to enhance the strength of recycled fibres. These approaches includemechanical treatment, chemical addition, and physical fractionation as well as blending with virgin fibres. In this study, two types of deinked old newsprint (ONP) pulp were subjected to blending with virgin fibres of rice straw. The ONP pulp was blended with rice strawpulp at 4 intervals ranging from0 to 100%addition. Itwas observed that blending ONP with rice strawpulp had enhanced the strength of the virgin fibre and vise versa. The modification of rice straw fibres was visually evaluated by scanning electron microscopy (SEM). It was observed that the addition of the flexible ONP pulp type2 seemed to fill up the voids in the paper sheet and created more bonding with rice straw fibres. Shrimps exoskeletons poweder, borax and cactus peel extract were added to paper board made from50%rice straw+50%ONP type2 pulp at percent of 2%based on oven dryweight pulp. The antimicrobial activity of each of these three additives was studied.