Forming Fabric Troubleshooting Flashcards
Why do forming fabrics need cleaning?
To lower accumulation and sheet breaks.
Fabric needs to be kept clean to be open for drainage.
What are important factors in cleaning of forming fabrics?
Water pressure
Shower distance
Jet quality - needs to be laminar flow
Oscillators - need correct movement.
Where can energy savings be made with fomring fabrics?
The weaving pattern
Raw materials
Caliper.
Can have special energy saving yarns which create better binding and can be thinner with same wear potential.
Also 4E yarns which are square rather than round to give more area.
What can too high pressure on showers do to forming fabrics?
Cause fibrillation
What can incorrect positioning of showers do to forming fabrics?
Can cause misting and fabric fibrillation.
Showers should be close or just under roll
Why do you need to be careful when chemical cleaning forming fabrics?
Strong alkaline will damage polyester yarns
Strong acid will damage polyamide yarns
What can you use in forming fabrics to help with edge wear
Life lines
Edge reinforcement
What can cause wrinkling of a forming fabric?
Too low tension - can cause issues for binder yarn.
How should you monitor forming fabrics?
Check the caliper
Check the seam (weakest point)
Check the tension
Use pencil to see if yarns have worn flat
Check cleanliness
What influences guiding (forming fabrics)
Contact area/weave pattern
Misalignment
Guiding paddle incorrect
Lab fabric tension
Too much water on guide roll
Potentially need fabric polishing or more PET.
What does too much air in stock lead to? (forming fabrics) and some reasons for this
Formation issues/quality issues
Deaerator not working, incorrect defoamer dosage, high refining making stock more difficult to drain.
