1) Forming fabric selection and tissue forming operations require careful engineering to maximize performance. Key factors include headbox setup, fabric tension measurement and control, shower design and operation, and separation angles. 2) Tissue forming fabrics must be tailored to the specific former, such as requiring fast drainage and stiffness for crescent formers. Fabric properties like stretch and cleanability impact tissue uniformity and machine efficiency. 3) Shower applications such as high pressure showers precisely applied can enhance fabric cleaning while avoiding damage. Proper shower spacing, pressure, and nozzles are critical for effectiveness.

1. Forming Fabric Applications
for Tissue Making
for Tissue Making
Bruce W Janda
Bruce W. Janda
Global Product Leader – Forming
AstenJohnson
AstenJohnson
PaperCon 2011 Page 1894

2. Key to Success  Engineered Approach
Fabric
Selection
FIBER LENGTH ANALYSIS
1200
1400
1600
1800
2000
s
STONE [CANADA] INC.
Stone Container Corp.
Kajaani
0
200
400
600
800
1000
1200
0.000 0.500 1.000 1.500 2.000 2.500 3.000
Fiber Length (mm)
Number
of
fibers
p
MILL AVRG L.W. W.W. 0.4 0.2
STNRPQ-01 0.64 1.61 2.4 57.9 41.9
STHOLA-05 0.63 2.56 3.5 74.3 70.7
j
Fiber Length
Analyzer
Operation
Furnish
Drainage Pressure is defined as P=T/R
be e gt ( )
Operation
Furnish
PaperCon 2011 Page 1895

3. Tissue Forming Operations
Getting the most out of a any forming fabric design
g y g g
requires careful attention to the fabric run
• Headbox set up and jet impingement
- Crescent Former
- Crescent Former
- Twin Wire
- Stratification
• Fabric tension measurement and control
• Cleaning shower design and operation
• Separation Angles
Separation Angles
• Know your furnish
- Fiber length
- Virgin vs. recycled
- Contaminants
- Chemicals
• Tissue Product Target
PaperCon 2011 Page 1896

4. Jet Impingement – need to look from both sides
I i l
• Impingement control
critical for good
formation
• Jet tangential to
Jet tangential to
drainage surface
• Avoid roll surface
impingement
A id i i t tifi d
• Avoid mixing stratified
furnish jets
Stock Splash – Flocculation
Poor Formation
Fingering effect
Ridge the Fabric – Poor Formation
Good Formation
PaperCon 2011 Page 1897

5. Fabric Tension Measurement
Triple and Double layer fabric designs
Huyck Tensometer vs PLI (daN/cm) Curve • New tissue formers
110
115
120
eter
Reading
Huyck Tensometer vs. PLI (daN/cm) Curve • New tissue formers
designed for fabric
tensions up to
14daN/cm (80pli)
95
100
105
Huyck
Tensome
14daN/cm (80pli)
• Huyck tensometer
insensitive above
9daN/cm (60pli)
90
3.50 4.37 5.25 6.12 7.00 7.87 8.75 9.62 10.50 11.37 12.25
Actual daN/cm Reading
( )
• Forming results
greatly affected by
the tension
changes
•Digital tensometer accuracy confirmed
•Measure slow or machine crawl speeds for safety
•Measure slow or machine crawl speeds for safety,
•Calibrate the on-line system for high speed operation.
PaperCon 2011 Page 1898

6. Shower Application
High Pressure Needle
High Pressure Needle
• Forming
– HP cleaning of fabric drainage channels
– Removes contaminates from surface
– Always locate near a roll for fabric stability
– Should follow knock off shower when possible
0.040 Inch nozzles
Flooded
3 inch spacing - Oscillated
3” to 5” from fabric – 0-15 into run
350 to 450 psig pressure
Knockoff
Lube
350 to 450 psig pressure
Knockoff
HP Needle
PaperCon 2011 Page 1899

7. Shower Application
High Pressure Needle Effective Cleaning Distance
3” 3 - 6” Beyond 6”
Distance: Comments:
0
0 -
- 3”
3”
3
3 -
- 6”
6”
> 6”
> 6”
Most effective cleaning – Distance & Pressure
Cleaning area: Medium cleaning action.
Jet breaks up: Hammer effect fibrillates yarns
Jet breaks up: Hammer effect fibrillates yarns
PaperCon 2011 Page 1900

8. Shower Application
High Pressure Needle Shower Damage = Warp Fibrillation
High Pressure Needle Shower Damage = Warp Fibrillation
PaperCon 2011 Page 1901

9. Shower Application
Roll Lubrication Shower
• Lubricates the doctor blade, allowing it to clean better and help
reduce wear on the roll cover.
• Located as shown 45 degree nozzles
6” - 8” spacing
8” from roll (100%
coverage)
25 t 35 i
25 to 35 psig pressure
Note: shower can be
located in either position
PaperCon 2011 Page 1902

10. Shower Application
High Pressure Flooded Nip
High Pressure Flooded Nip
• Push fibers out to sheet side – improve he chisel and HP showers efficiency
• Flush ash and other contaminates that plug and wear base of the fabric.
• Located in a nip with a good amount of wrap for better hydraulic action.
Located in a nip with a good amount of wrap for better hydraulic action.
30 degree nozzles
3 inch spacing
Flooded
4” to 10” from fabric (double coverage)
200 to 400 psig pressure
Knockoff
Lube
HP Chisel
HP Needle 30º Fan nozzles
3 inch spacing - Oscillated
High Pressure Chisel
High Pressure Chisel
p g
5.5” from fabric
15°- 30º Angle into run
• HP cleaning of fabric drainage channels
• Removes contaminates from surface
• Locate near roll for effective cleaning
200 to 400 psig pressure
• Follow knock off shower when possible
PaperCon 2011 Page 1903

11. No Application Function Shower Type
Space
Ø PSI GPM / IN Nozzle Distance Water Quality
Knockoff 200 to 400 3" - 4"
Shower Recommendation for Machine Clothing
1 Fiber/Sheet Chisel Contamination Stationary 30° Fan 3" PSI 1.0 - 2.0 0.125" With 30° angle CWW
2 In-Side HPN Fabric Cleaning Oscillating Needle Jet 3"
200 - 300
PSI .18 - .20 0.040" 3" - 4" Fresh
3 Sheet Side HPN Fabric Cleaning Oscillating Needle Jet 3"
200 - 300
PSI .18 - .23 0.040" 3” – 4” Fresh
4 Flooded Nip
Knockoff
Contamination Stationary 25° Fan 3"
150 to 250
PSI 2.0 – 3.5 0.141" 4" - 6" CWW <150-PPM
5 Lube Shower Lubrication Stationary 45° Fan 6" - 8" 25 - 30 PSI .07 - .09 0.055" 6” – 8” CWW
6 Headbox Apron
Fiber Build up
Removal Stationary 45° Fan 6" 30 - 40 PSI .06 - .07 0.055" 8" CWW
7 Release Shower
Coating Application
to Fabric Stationary 45° Fan 6" 40 - 60 PSI .07 -.09 0.055" 8" N/A
8 Tail Cutter
Threading the
Sheet
Intermittent Needle
Jet N/A 60 - 80 PSI 1.5 - l/min 0.040"
5" - 6" Distance
With 5° angle
into Run Fresh
9 Suction Breast Roll
Cleaning
Contamination Oscillating Needle Jet 3"
350 - 600
PSI .21 - .25 0.040" 4" CWW
10 Chemical Cleaning Oscillating 45° Jet 3" 40 - 60 Calculate 0.094" 4" Fresh
11
Wire Edge
Cleaning Edge build-up
Stationary Fan
45º Tilt N/A
150 – 200
PSI Calculate Calculate 3” CWW
Edge Cooling Cool the edge of
1
Edge Cooling
Sprays
Cool the edge of
the felt Stationary 45° Fan 2" 15 - 25 .07 -.09 0.055" 4" Fresh
2 Lube Shower Lubrication Stationary 45° Fan 6" - 8" 25 - 30 PSI .07 - .09 0.055" 8" CWW
3 Flooded Nip
Knockoff
Contamination Stationary 25° Fan 3"
150 to 250
PSI 2.0 – 3.5 0.141" 4" - 6" CWW <150-PPM
4 In-Side HPN Felt Cleaning Oscillating Needle Jet 3"
200 - 250
PSI .17 - .20 0.040" 3" - 4" Fresh
5 Vacuum Box Lube Lubrication Oscillating 45° Fan 6" - 8" 25 - 30 07 - 09 055" 8" CWW
5 Vacuum Box Lube Lubrication Oscillating 45 Fan 6 - 8 25 - 30 .07 - .09 .055 8 CWW
6 Fiber/Sheet Chisel
Knockoff
Contamination Stationary 30° Fan 3"
100 to 200
PSI 0.5 - 1.0 0.125"
3" - 4"
With 30° angle CWW
7 Sheet Side HPN Felt Cleaning Oscillating Needle Jet 6" 150 - 250 .06 - .07 0.040" 3" - 4" Fresh
8 Chemical Cleaning Oscillating 45° Jet 3" 40 - 60 Calculate 0.094" 4" Fresh
9 T il C tt
Threading the
Sh t
Intermittent
N dl J t N/A 60 80 PSI 1 5 l/ i 0 040"
5" - 6" Distance
With 5° angle
i t R F h
9 Tail Cutter Sheet Needle Jet N/A 60 - 80 PSI 1.5 - l/min 0.040" into Run Fresh
10 Yankee Coating
Protect Metal
Surface
110° Fan & 10° Off
Center 6" 50 - 90 3' / sec 0.62" 4" - 7" Fresh
PaperCon 2011 Page 1904

12. Transfer Geometry
R d d S ti l 3º 7º
Recommended Separation angle 3º-7º
PaperCon 2011 Page 1905

13. Twin Wire Former
Fabric Requirements
O t P iti
Outer Position:
Fast Drainage
High Fiber Support
Guide
High Fabric Stiffness and Stability
Low Fabric Stretch
Easy to Clean
Stretch
Guide
OUTER
INNER
(CONVEYING) (FORMING)
Guide
y
Inner :
Easy to Clean
L F b i St t h
Stretch
Low Fabric Stretch
Good Durability for Life
High Fiber Support (TAD and Suction)
- Slide 13
PaperCon 2011 Page 1906

14. Stiffer fabric means better CD profile!
8
10
CMD
FABRIC STIFFNESS
4
6
8 CMD
MD
Stiffness (in grm)
0
2
1 2 3 4
Stiffness (in grm)
Single
Layer
ES Double
Layer
Std Triple
Layer
SSB
Triple Layer
Layer y y
Fabric stiffness has become more important with new ultra
dilution head boxes (up to 200 gpm per inch)
dilution head boxes (up to 200 gpm per inch)
PaperCon 2011 Page 1907

15. Fabric Stiffness = Tissue Uniformity
SSB triple layer
SSB triple layer
PaperCon 2011 Page 1908

16. Fabric Design Impact on Tissue Sheet Formation
PaperCon 2011 Page 1909

17. Crescent Former
Fabric Requirements
Fabric Requirements
Width Stability – Sheet Width Control
High Fabric Stiffness – CD Profile
Fast Drainage – High Speed Operation
High Fiber Support- Formation and Retention
Low Fabric Stretch – High Tension Operation
g p
Easy to Clean – Efficient Showering
Low Water Carry back – Dry Return Run
Recommended separation angle 6º
Recommended separation angle 6º-
- 6½º
6½º
PaperCon 2011 Page 1910

18. Crescent Former Edge Trim Recommendations
Edge Trim Options
• Trim squirt on Press Felt
• Trim with Wire
a. Filled edges
b. Edge beads
c. No edge discontinuity
d 2 Sided trim needs stable
d. 2-Sided trim needs stable
width fabric design
PaperCon 2011 Page 1911

19. Suction Breast Roll Former
Fabric Requirements
Fast Drainage – Very Short Forming Zone
High Fiber Support – Formation and Retention
Low Caliper – Drainage and Showering
Fabric Durability - Life
y
#1
#1
#2 #2
#1
#1
PaperCon 2011 Page 1912