papermaking properties of the eucalyptus · 2012. 11. 7. · •papermaking process design...

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Papermaking Properties of the Eucalyptus Wood & Fibers

Celso Foelkel

http://www.eucalyptus.com.br/eucaliptos/PT14_PropPapeleiras.pdf


Not a scientific presentation...

But a lecture addressed to a distinguished audience...


Eucalyptus Pulping and Papermaking

Simple things of the real life...


Wood is a variable raw material...


and so does pulp..


paper...


and pulp and paper manufacturing processes...


Wood variability is part of our lives since the early papermaking days


Efforts to evaluate and to tame variability are not

equally distributed


No matter what wood we are talking about - they are variable at the fiberlines -

Even clonal wood material or single species supplies


This variability is partly natural and partly caused by man...


Variability is part of our lives


Even so, we are reckless to measure and to control it...

•sampling sizes are inappropriate •based on composite sampling

•number of replications is small •few statistical tools are used

•focus on mean/averages (or averages of averages) and not range and extremes

•statistic errors are not evaluated, even forgotten that they exist

•a lot of risks involved to take safe decisions (but managers do not talk or care about this !!!!)


What means that...

A lot of analyses are made to provide numbers and to please managers


As a result...

•Pulpmakers complain about the wood... •Papermakers complain about the pulp...

•Customers of paper complain about the paper performance and quality they purchase...


The results coming from these facts are...

•Different mills have different specifications for wood and/or pulp

•Different Eucalyptus pulps have different papermaking performances

•There is not an universal Eucalyptus pulp: one to be used with success in any of the world papermachines


Each paper-machine, each pulp mill, any pulp & paper process, any fibrous raw material although

similar are specific and unique.

They all have own key-factors to be controlled and optimized.


• Why are some Eucalyptus pulps different from others ?

• Why are some Eucalyptus pulps preferred by some customers and not by others manufacturing the same paper product?

• Why some pulps, even when offered by lower prices, are not attractive to the papermakers ?

• Why one clone performs well in one pulp mill and not as well in another one close to ?


Dialogue is vital..

when visiting your market pulp customer you should ask him...

• main paper attribute being aimed?

• why Eucalyptus fibers are being used? Or why not?

• what does he need in the pulp we supply?

• What does he love in the pulp we provide? In case he does, sure...

• which are the main paper-mill bottlenecks?


Dialogue is vital..

when visiting your customer you should try to understand his objectives and pressures

• costs savings

• fewer breaks

• less broke generation

• better runnability

• end-product requirements

• environmental restrictions (carbon footprints, certified wood-fibers, AOX stringent legislation, etc.)


Dialogue is vital...

The same with regard to the wood supply...

Performance and specification are built on these foundations


Dialogue is vital..

Each fiberline has specific oddities...

Each forest plantation also...

The same with regard to the papermaking process...


What makes a raw material really special?

“Best fitness to the user”

• End-product specifications ?

• Process runnability ?

• Operational efficiencies ?

• Easy-life to the managers and operators ?

• Overall cost reductions ?


Then - real world comprises:

Lots of variability everywhere...

- remember this fact -

•How to tame variability?

•How to live together with variability?

•How to take advantages of this fact?

•How to use it in our favor?


Causes for pulp quality variability:

•wood differences

•chip quality management

•pulping processes

•bleaching line

•washing presses

•drying (flakt, drums, flash)


Some causes for pulp quality variability:

•hemicelluloses

•fiber charges

•fiber population

•individual fiber strength

•fines

•water retention value

•fiber flexibility

•cell wall thickness

•bonding ability


Is there a single and most important wood or pulp characteristic or fiber property?

The mill bottlenecks will define what is important...

“This is real life, both to pulp and paper manufacturing”


The mill bottlenecks will define what is important...

“Removed the bottleneck, another specification should be raised, immediately”


The manufacturer is always squeezed by:

•Commercial demands

•Cost reduction demands

•Production objectives

He hates variability, and he considers that we suppliers are responsible for his difficulties


The manufacturer is always requesting :

Please, give me a stable quality raw material

- one I may predict behavior -


What is really an Eucalyptus wood ?

•Fibers

•Vessel elements

•Fines

•Chemicals (some to be preserved and others extracted)


Most important quality

properties to pulp-makers

Wood properties

•wood basic density

•fiber dimensions(wall thickness...)

•hemicellulose content

•lignin content

•lignin quality

•wood extractives

•ash content

Pulping process

•chip cleanliness

•chip dimensions

•wood health

•alkali consumption

•pulping yield

•wood specific consumption

•total dry solids/adt pulp

•pulp cleanliness

•bleachability (bleaching chemicals consumption)

•pulp dewatering, drainage


What is really an Eucalyptus pulp ?

•Fibers (over 90% on weight)

•Vessel elements

•Fines (Parenchyma cells and debris)


Definitions for papermakers

Machine productivity:

• fast speed

• fast drainage

• high consistency after the wet end

• excellent sheet consolidation

• minimum breaks

Quality

• maximum achievements in paper specifications

• minimum generation of off-grades and broke

•minimum complaints from users

No matter what the papermaker is manufacturing,

a commodity or a specialty product, his dreams are the same


Most important quality

properties to papermakers

Fiber properties

•fiber population

•coarseness

•fiber deformations

•individual fiber strength

•hemicellulose content

•fiber charges

•fiber flexibility

•fines content,

•cell wall thickness

Paper-machine •drainage speed

•refining ability

•WRV

•swelling ability

•formation

•wet web strength

•water absorption

•sheet smoothness

•paper softness

•printing ability

•dimensional stability

•dry handsheet properties:

•bulk; porosity;

•tensile; tear;

•opacity;

•stiffness;etc


Most important

technological factors to Eucalyptus pulp and paper manufacturing

At forests

•Eucalyptus species

•clone

•forest age at harvesting

•silvicultural practices and environmental causes effecting wood quality

•wood defects

At mills

•“wood mix”

•“pulp mix”

•mill technological age

•type of paper mill: integrated or not

•pulp and fiberline design

•papermaking process design

•bottlenecks

•broke handling


Eucalyptus Fibers “why do papermakers love them?”

• Unique fiber properties ? • Excellent paper-machine behavior ?

• Lower cost in relation to long fibers ?

Eucalyptus fibers have in many cases a position of problem-solver pulp stuff...

(WE SHOULD BETTER EXPLORE THIS FACT) (to product specification and machine runnability)


Eucalyptus Fibers “why do we love them?”

Because they worth - no doubt about


Well, this is all my

friends.

Thank you very much.

Good luck with the utilization of Eucalyptus as fibrous raw materials

papermaking properties of the eucalyptus · 2012. 11. 7. · •papermaking process design...

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