Comparison of plate and conical fillings in refining of bleached softwood and hardwood pulps

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Comparison of plate and conical fillings in refining of bleached softwood and hardwood pulps. / Koskenhely, Kari; Nieminen, Kaarlo; Hiltunen, Eero; Paulapuro, Hannu.

In: PAPERI JA PUU-PAPER AND TIMBER, Vol. 87, No. 7, 2005, p. 458-463.

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@article{cca4bc8926b84e12ad25984ab927081c,
title = "Comparison of plate and conical fillings in refining of bleached softwood and hardwood pulps",
abstract = "The purpose of this study was to compareplate and conical refiner fillings in laboratoryrefining of softwood and hardwood pulpfibers. A better dewatering-tensile strengthcombination was achieved when SWK wasrefined with conical fillings, and the developmentof strength was found to be insensitiveto variations in refining intensity inthe range of 1.3-4.0 J/m. A bar microprofilewas measured with the aid of a profilometer.The leading edges of conical filling bars werefound to be rounder. A possible reason forthe better tensile strength of pulp refinedwith conical fillings is that the round edgehelps large SW fiber flocs to enter the spacebetween the bars, resulting in less heterogeneousor more efficient treatment of fibers.The recorded gap closure values supportedthe above interpretation. The gap betweenconical fillings was found to become widerwhen pulp consistency and thus the tendencyfor fiber flocculation increased, whereasincreased pulp consistency decreased thegap between plate fillings, which was furtherreflected as increased fiber cutting. The reductionin fiber length appears proportionalto the increase in gap closure, supportingthe earlier theory that fibers are squeezedand crushed between the bars. More attentionshould be paid to the wear of fillingmaterials when refining long-fiber pulp. Afilling material which wears so that the baredges are rounded would seem to promotehigh tensile strength and high average fiberlength.",
keywords = "laboratory refining, intensity, softwood, hardwood, energy swelling, bar profile",
author = "Kari Koskenhely and Kaarlo Nieminen and Eero Hiltunen and Hannu Paulapuro",
year = "2005",
language = "English",
volume = "87",
pages = "458--463",
journal = "PAPERI JA PUU-PAPER AND TIMBER",
issn = "0031-1243",
number = "7",

}

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TY - JOUR

T1 - Comparison of plate and conical fillings in refining of bleached softwood and hardwood pulps

AU - Koskenhely, Kari

AU - Nieminen, Kaarlo

AU - Hiltunen, Eero

AU - Paulapuro, Hannu

PY - 2005

Y1 - 2005

N2 - The purpose of this study was to compareplate and conical refiner fillings in laboratoryrefining of softwood and hardwood pulpfibers. A better dewatering-tensile strengthcombination was achieved when SWK wasrefined with conical fillings, and the developmentof strength was found to be insensitiveto variations in refining intensity inthe range of 1.3-4.0 J/m. A bar microprofilewas measured with the aid of a profilometer.The leading edges of conical filling bars werefound to be rounder. A possible reason forthe better tensile strength of pulp refinedwith conical fillings is that the round edgehelps large SW fiber flocs to enter the spacebetween the bars, resulting in less heterogeneousor more efficient treatment of fibers.The recorded gap closure values supportedthe above interpretation. The gap betweenconical fillings was found to become widerwhen pulp consistency and thus the tendencyfor fiber flocculation increased, whereasincreased pulp consistency decreased thegap between plate fillings, which was furtherreflected as increased fiber cutting. The reductionin fiber length appears proportionalto the increase in gap closure, supportingthe earlier theory that fibers are squeezedand crushed between the bars. More attentionshould be paid to the wear of fillingmaterials when refining long-fiber pulp. Afilling material which wears so that the baredges are rounded would seem to promotehigh tensile strength and high average fiberlength.

AB - The purpose of this study was to compareplate and conical refiner fillings in laboratoryrefining of softwood and hardwood pulpfibers. A better dewatering-tensile strengthcombination was achieved when SWK wasrefined with conical fillings, and the developmentof strength was found to be insensitiveto variations in refining intensity inthe range of 1.3-4.0 J/m. A bar microprofilewas measured with the aid of a profilometer.The leading edges of conical filling bars werefound to be rounder. A possible reason forthe better tensile strength of pulp refinedwith conical fillings is that the round edgehelps large SW fiber flocs to enter the spacebetween the bars, resulting in less heterogeneousor more efficient treatment of fibers.The recorded gap closure values supportedthe above interpretation. The gap betweenconical fillings was found to become widerwhen pulp consistency and thus the tendencyfor fiber flocculation increased, whereasincreased pulp consistency decreased thegap between plate fillings, which was furtherreflected as increased fiber cutting. The reductionin fiber length appears proportionalto the increase in gap closure, supportingthe earlier theory that fibers are squeezedand crushed between the bars. More attentionshould be paid to the wear of fillingmaterials when refining long-fiber pulp. Afilling material which wears so that the baredges are rounded would seem to promotehigh tensile strength and high average fiberlength.

KW - laboratory refining

KW - intensity

KW - softwood

KW - hardwood

KW - energy swelling

KW - bar profile

M3 - Article

VL - 87

SP - 458

EP - 463

JO - PAPERI JA PUU-PAPER AND TIMBER

JF - PAPERI JA PUU-PAPER AND TIMBER

SN - 0031-1243

IS - 7

ER -

ID: 1510685