Finely ground mechanical pulp (RMP) of kenaf bast fibers

Researchers at the University of Mississippi use a 300-mm Sprout-Bauer refiner. In the intermediate laboratory, two types of raw materials, i.e., ramie bast fibers and bast fibers containing 22% wood cores, are chopped and then soaked in 35°C water. Dip for 4 h, then pass through several refiners in a refiner until the pulp freeness is 125-150 ml CSF. The first-stage refining concentration was (35±1)%, and then the pulp consistency of the two raw materials was 15% and 22%, respectively; the control factors in the refining process were pulp consistency, the number of multistage refining passes, and the refining interval. For controlling the ratio of fibers to fine fractions, the number of disc space and refining passes is a very important parameter. Alkali-hydrogen peroxide bleached RMP of two raw materials, good bleaching performance, hydrogen peroxide dosage 3%, NaOH 1% to 3%, DTPA1%, sodium silicate 5% and magnesium sulfate 0.5%, pulp concentration 12% , The temperature of 60 °C to maintain 2h, whiteness of bleached pulp up to 75% ISO. The physical mechanical strength and optical properties of handsheets made from two raw materials, ramie bast fibers RMP, were determined. The results showed that the ramie bast fibers and the RMP of the kenaf bast fiber containing 22% of the wood core not only Suitable for the production of newsprint, but also for copying higher grade paper, such as low-quantitative coated paper, to reduce the amount of softwood bleached kraft pulp.