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.