Fibre Morphological Characteristics of Kraft Pulps of Acacia melanoxylon Estimated by NIR-PLS-R Models.

Helena Pereira,António Santos,Ofélia Anjos

doi:10.3390/ma9010008

Helena Pereira, António Santos + Show 1 more

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https://doi.org/10.3390/ma9010008

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Abstract

In this paper, the morphological properties of fiber length (weighted in length) and of fiber width of unbleached Kraft pulp of Acacia melanoxylon were determined using TECHPAP Morfi® equipment (Techpap SAS, Grenoble, France), and were used in the calibration development of Near Infrared (NIR) partial least squares regression (PLS-R) models based on the spectral data obtained for the wood. It is the first time that fiber length and width of pulp were predicted with NIR spectral data of the initial woodmeal, with high accuracy and precision, and with ratios of performance to deviation (RPD) fulfilling the requirements for screening in breeding programs. The selected models for fiber length and fiber width used the second derivative and first derivative + multiplicative scatter correction (2ndDer and 1stDer + MSC) pre-processed spectra, respectively, in the wavenumber ranges from 7506 to 5440 cm−1. The statistical parameters of cross-validation (RMSECV (root mean square error of cross-validation) of 0.009 mm and 0.39 μm) and validation (RMSEP (root mean square error of prediction) of 0.007 mm and 0.36 μm) with RPDTS (ratios of performance to deviation of test set) values of 3.9 and 3.3, respectively, confirmed that the models are robust and well qualified for prediction. This modeling approach shows a high potential to be used for tree breeding and improvement programs, providing a rapid screening for desired fiber morphological properties of pulp prediction.

Highlights

Pulp is a major global commodity forest-based product that consists of the dissociated cells of the raw material, usually named pulp fibers
The fiber length and width of the unbleached pulps of A. melanoxylon obtained in this study ranged from 0.66 to 0.79 mm and 16.4 to 22.3 μm, respectively, with an average of 0.73 ̆ 0.03 mm and
When considering all the samples of this study (60 samples), a good calibration for the fiber length and fiber width of the unbleached Kraft pulp was obtained with the spectral data of the length and fiber2 width of the unbleached Kraft pulp was obtained with the spectral data of the woodmeal with r 2 = 96.5% and 95.0%, Rank = 8 and 6, root-mean-square error of estimation (RMSEE)

Summary

Introduction

Pulp is a major global commodity forest-based product that consists of the dissociated cells of the raw material, usually named pulp fibers. The fiber morphological properties are important quality parameters for pulp and paper properties and they are measured both for research purposes and industrial quality control. The fiber characteristics greatly influence the quality and properties of the final product, e.g., they are frequently correlated with the physical and mechanical properties of paper and paperboard [1,2,3,4,5,6]. Strong correlation between fiber length and tear index was reported for both hardwoods and softwoods [7,8,9,10,11]. Tensile and tear strength of paper increase with fiber length, especially in weakly bonded sheets [12,13]. Fiber length influences the papersheet formation and its uniformity [13,14]

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