Warm water, starch, fibre fines and a closed loop – a paper machine is close to a perfect home for bacteria and fungi. Left alone, they build slime on chest walls, pipes and the headbox. Sooner or later a lump breaks loose and lands in the sheet.
Signs of a slime problem
- Holes, spots and slime “boogers” in the paper.
- Breaks that come and go without a clear cause.
- Sour or rotten-egg smell around chests and the white water system.
- Falling pH and starch that seems to stop working.
- Felts filling up faster than usual.
Why it gets worse over time
Mills are closing their water loops to save water and effluent. That is good practice, but it also concentrates nutrients and raises temperature – ideal for microbial growth. More starch and recycled fibre add even more food.
How antislime agents help
An antislime agent controls the microbes before they build deposits. Stickies control and biocide products help with the sticky mix of slime and contaminants that often forms together.
Benefits of good slime control
- Fewer holes, spots and customer complaints.
- Fewer unplanned breaks and wash-ups.
- Longer felt and wire life.
- Starch and sizing chemicals work as intended.
- A cleaner, safer workplace with less odour.
A practical programme
- Clean first. A boil-out or chemical wash during shutdown gives the biocide a clean start.
- Dose continuously or in slugs at the white water silo, broke chest and stock chests, depending on the product.
- Monitor – simple counts or ATP tests show whether the dose is right.
- Rotate or combine biocides if resistance develops.
- Fix dead zones – corners and stagnant pipes where stock sits for hours.
Use cases
- Paper & pulp, tissue and kraft mills.
- Cooling water and water treatment systems.
- Sugar mills, where microbes cause sucrose loss.
Seeing holes, odour or unexplained breaks? Tell us your machine and water system – we will suggest an antislime programme. Get help →