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Author:Huttunen, Olli
Title:Kemi-termomekaanisen massan ominaisuuksien optimointi
Optimization of the properties of chemi-thermomechanical pulp
Publication type:Master's thesis
Publication year:2013
Pages:105 s. + liitt. 5      Language:   fin
Department/School:Puunjalostustekniikan laitos
Main subject:Paperi- ja painatustekniikka   (P3003)
Supervisor:Paltakari, Jouni
Instructor:Syväoja, Kati ; Nieminen, Mikko
Electronic version URL: http://urn.fi/URN:NBN:fi:aalto-201401141122
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Location:P1 Ark Aalto  2290   | Archive
Keywords:chemi-thermomechanical pulp
bulk
chip refining
chip delay
preheating pressure
kemi-termomekaaninen massa
kemi-hierremassa
CTMP
bulkki
Scott Bond
hakkeen viipymä
esilämmittimen paine
Abstract (eng):The aim of this thesis was to study the main factors and variables affecting the properties of high freeness spruce (Picea abies) chemi-thermomechanical pulp (CTMP).
The study in the experimental part contributes to improving the bulk level of the end product at CTMP-plant.

Due to the small number of existing CTMP-plants, the amount of published studies is very limited.
In addition, the existing plants produce a wide variety of end products for multiple end uses.
Therefore, it is very difficult to create high quality collections of the CTMP properties.
In general, the most important factors and subprocesses affecting the properties of CTMP are the impregnation stage, the main refining stage, and the bleaching stage.
Also the quality of the chip raw material can be found to play a crucial part in the properties of the pulp.
The main variables in impregnation stage are pH and concentration of the impregnation liquor.
The most important variables in main refining are type of refining plates, refining habit, and preheating pressure.
In bleaching stage the most significant variables are bleaching chemical, chemical concentration, pH, and the processing habit.
The most important variables of chip raw material are moisture content, cleanliness, chip dimensions, and position in stem.

In the experimental part two studies were performed to improve the bulk of the pulp.
The first experiment considered the pH and the concentration of the impregnation liquor.
The second experiment investigated the effects of the preheating pressure and the chip delay between the impregnation stage and the main refining stage.
All trials were executed in mill scale and in respect to normal quality standards.
It was observed that the most significant variable affecting the bulk of the pulp was the preheating pressure.
By increasing the preheating pressure from 160 kPa to 220 kPa the bulk of the pulp was improved by almost 10 %.
Properties of the impregnation liquor and the delay of impregnated chips before refining did not present significant effect to the properties of the pulp in these studies.
Abstract (fin):Tämän työn tavoite oli selvittää kuusesta (Picea abies) valmistettavan korkean freeneksen kemi-termomekaanisen massan (CTMP) ominaisuuksiin vaikuttavat merkittävimmät tekijät ja muuttujat.
Kokeellisen osan tavoite oli nostaa CTMP-laitoksen tuottaman massan bulkin tasoa.

CTMP-laitosten niukasta määrästä johtuen alalta löytyy erittäin vähän kattavaa julkaistua tutkimusta.
Lisäksi olemassa olevien laitosten tuottamat massalaadut vaihtelevat voimakkaasti ja vertailujen tekeminen on erittäin haastavaa.
Yleisesti CTMP-massan ominaisuuksiin vaikuttavat merkittävimmät osaprosessit ovat imeytys-, jauhatus- ja valkaisuvaiheet.
Hakeraaka-aineen laadulla todetaan olevan mahdollisesti jopa merkittävin vaikutus lopputuotteen laatuominaisuuksiin.
Imeytysvaiheen tärkeimmät muuttujat ovat imeytysliuoksen pH ja konsentraatio.
Jauhatusvaiheen tärkeimmät muuttujat ovat jauhinterät, ajotapa ja esilämmittimen paine.
Valkaisuvaiheen tärkeimmät muuttujat ovat valkaisukemikaali, konsentraatio, pH ja ajotapa.
Hakkeen tärkeimmät muuttujat ovat kosteuspitoisuus, puhtaus, palakoko ja sijainti rungossa.

Kokeellisessa osassa tutkittiin imeytysliuoksen pH:n ja konsentraation sekä imeytetyn hakkeen viipymän ja esilämmittimen paineen vaikutusta massan bulkkiin ja Scott Bond-palstautumislujuuteen.
Kaikki kokeet suoritettiin laitosmittakaavassa normaalien laatutekijöiden mukaan.
Tutkimuksissa selvisi, että merkittävin pääjauhatusvaiheen puskulinjanäytteiden bulkkiin vaikuttava prosessitekijä on esilämmittimen paine.
Esilämmittimen painetta nostamalla 160 kPa:sta 220 kPa:iin bulkin taso nousi lähes 10 %.
Muilla tutkituilla tekijöillä ei todettu olevan merkittävää vaikutusta näissä koeajoissa.
ED:2014-01-19
INSSI record number: 48454
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