1 adding & preserving quality - finishing & converting balbir singh & carl ingalls...
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1
Adding & Preserving Quality-
Finishing & Converting
Balbir Singh & Carl Ingalls
Tissue World Americas 2002
2
Solid Mech.Mech. E.Ind. E.
ChemistryChem. E.Mech. E.
PaperMachine
P/MDryEnd
WetEnd
Converting Packaging
Fluid & Semi-Fluid State
SolidState
Cre
peD
octo
r
Changing Role of Converter
3
Finishing Processes
Embossing
Ply bonding or laminating
Lotionizing
Printing
Calendering
4
Finishing in Converting
PaperMachine
WetEnd
P/MDryEnd
“Converting” Packaging
CrepeDoctor Practical
location for finishing
processes
The converter’s domain
Alternate location for calendering
5
Why Calender?
Bulk Reduction Bulk Leveling
Bulk Reduction
Han
dfee
l Gai
n
6
Calender Nip
Crowning Zero-Crown
Skewing Nip-Control
7
Calender Gap Control
Load activatedFor handfeel
Against stopsBulk control
8
Handfeel Quality Curves
HF gain
Bulk loss
Bulk
Before calendering
Gain or loss, relative to the base paper.
Actual values of product properties.
More calendering
Target HF
Base paper HFHF
Before calendering
More calendering
9
Finishing Is a Balancing Act
Handfeel
BulkCalenderingBulk
StrengthEmbossingHandfeel
AbsorbencyLotionizing
10
Process Control Curve – Embossing
Nip Line Load (pli)No embossing(base sheet) More embossing
Base CDT
Embossed CDT
Embossed Bulk
Base Bulk
Base MDT
Embossed MDT
Operating range
11
Quality Control Curve – EmbossingB
ulk
Base paper bulk & CDT(before embossing)
CDT
CD
T range
Bulk range
Target Window
12
Converter’s Needs
Bulk
Stretch
Strength
P P
F F
e
b
13
Variability
Uneven BulkTapered ReelUneven Rolls
Uneven strengthPoor trackingSheet breaks
Holes & NicksSheet breaksPoor quality
14
Reel Mechanics
Reel Radius
Reel Radius Reel Radius
Reel Radius
Laye
r P
ress
ure
Ten
sile
Str
ess
Nip
Pli
Bul
k
15
Reel Types
Secondary Arm Reel
Linear Reel
16
Bulk: Thickness Under Pressure
Pressure
Bul
k
Embossing crushed, but not crepe.
All 3 sheets crushed.
FlatCreped Embossed
Embossing is not crushed.
17
Product Properties
•Bulk – fullness, thickness under pressure.
•Strength – resist failure during use.
•Absorbency – remove liquid.
•Handfeel – smoothness, cushion, drape.
•Ply count – implies quality.
•Visual appeal – implies quality.
How the user will experience the product.
18
Rewinders
Two-Drum Horizontal Rail
2-NipsWeighting/Un-weightingDrum Speed Differential
One-NipOne Speed
19
Tissue Winders
Center Winder Surface Winder
20
Folder
LongitudinalFold Plows
TransverseFold Rollers
21Draw RollsDancer Rolls
Calender Rolls Bowed Roll
Combating Tools
22
Grouping Combating Tools
1. Unwind Stand
2. Embosser Stand
Dancer
Skew Roll
Nip Rolls
Embosser
Bow Roll
Tension Roll
Draw Rolls
Bow Roll
23
A Diagnostic Tool0.50
Bul
k
Base paper bulk & CDT(before embossing)
CDT0 50 100 150 200 250
0.10
0
0.20
0.30
0.40 Tar
get
Win
dow
CD
T range
Bulk range
24
Comparing Embossing Curves
ABC
0.50
Bul
k
CDT0 50 100 150 200 250
0.10
0
0.20
0.30
0.40
CD
T range
Bulk range
25
Specifying the Base Paper
Win
dow
for
E
mbo
ssed
P
rodu
ct
Pro
pert
ies
Win
dow
for
B
ase
Pap
er
Pro
pert
ies
CD
T range
Bulk range
Bul
k
CDT
26
Conclusion
Finishing• Finishing adds quality
during converting.• Focus on end-use
properties.• Manage tradeoffs
between properties.• Use Finishing Curves:
- set base specs
- centerline process
- diagnose problems
Converting• Converting should
start at crepe doctor.• Make the reel uniform
and soft.• Avoid rewinding.• Match equipment with
the product.• Provide necessary
combating tools.
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