Effects of Supplementary Alkali after Alkaline Peroxide Treatment on the Properties of Bleached Kraft Pine Fluff Pulp

Abstract

Effects of dual-treatment on cellulose fiber quality, micro-structure appearance, crystalline structure, hydrogen bonds, and surface elements were analyzed using a fiber quality analyzer (FQA), scanning electron microscope (SEM), wide-angle X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS), respectively. In comparison to the untreated pulp, the brightness of pulp increased by 51.71%, whereas the apparent density and burst strength index of the pulpboard decreased by 11.76% and 48.18%, respectively. The absorption time, absorbability, and bulk of the fiber obtained by defibering the pulpboard decreased by 47.40%, 8.33%, and 5.32%, respectively, when it had been subjected to supplementary alkali. With the analysis of FQA and SEM, fiber swelled and curled, its surface was relatively smooth, and filaments of its partial surface area were exposed as a result of the supplementary alkali. Additionally, XRD analysis, FT-IR analysis, and XPS scanning spectra all showed that the crystallinity degree of fiber decreased by 45.10%, indicating more crystal structures were converted into amorphous structures. The proportion of total intra-molecular hydrogen bond intensity to total hydrogen bonds increased. The -OH content on fiber surface only decreased by 4.15%, compared with those of the untreated pulp, when the fiber was subjected to the two-step chemical treatment.

Energy efficiency challenges in pulp and paper manufacturing: A tutorial review

“…15, the combination of oxidation and alkaline conditions induces swelling of the wood material, which contributes to easier separation during the refining (deGroot et al 1997;Chang et al 2012). Such effects can be further enhanced by treatment with carboxymethyl cellulose (Cheng et al 2013) or supplementary alkali (Xu et al 2016). For alkaline peroxide mechanical pulping (APMP) of poplar, the specific refining energy required to achieve Canadian Standard Freeness levels in the range of 200 to 350 mL is about 3.3 to 4.3 GJ/tonne (Hart et al 2009).…”

Impact of Various pH Levels on 4-Methyl Catechol Treatment of Wood

“…Under alkaline conditions, the hydrogen bond structure of wood ruptured when the concentrated alkali permeated into the fiber from outside to inside (Zheng et al 2012). The proportion of intra-molecular hydrogen bonds increased, while the proportion of total intermolecular hydrogen bonds decreased (Xu et al 2016). Consequently, it was expected that more hydroxyl groups would be exposed after the rupture of hydrogen bonds and the cohesion of the fiber would decrease, thus increasing the disintegration of the fiber performance of raw wood (Villasante et al 2013;Boonstra et al 2007).…”

Carbon Footprint of Bleached Softwood Fluff Pulp: Detailed Process Simulation and Environmental Life Cycle Assessment to Understand Carbon Emissions

“…23 Critical features of FP are its absorbency, bulkiness, and relatively weak bonding strength for ease of defibration in a dry condition before its use in hygienic products. 24 This study presents the carbon footprint of FP production based on process simulation using WinGEMS, a specialized simulation tool for the P&P industry. 25 The biogenic and anthropogenic carbon flow and the energy flow for a standard FP mill were determined using mass and energy balances.…”

“…Pulp for paper applications tends to have resins and waxes that interfere with the absorption and movement of fluids within an absorbent product; therefore, different operation conditions are used to produce a quality FP . Critical features of FP are its absorbency, bulkiness, and relatively weak bonding strength for ease of defibration in a dry condition before its use in hygienic products …”