A mill in Indonesia producing both tissue and printing/cultural paper, with a recycled pulp line, came to us with a familiar complaint: they ran a single defoamer everywhere, but foam kept returning in the white water circuit, specks showed up on high-grade printing paper, and their effluent system foamed badly. Below is the key technical consultation.
One Product, Many Foams
Q:We use one defoamer across the whole machine, but foam keeps coming back in the white water and we see specks on high-grade paper. Why doesn't one product work everywhere?
A:Because foam at different points has different causes, and a single general product is always a compromise. White-water foam is driven by surfactants and recycled-fiber contaminants - it's persistent and needs a defoamer that survives a dirty system and stays dispersed. On high-grade printing paper, the visible defect is usually residue from the defoamer itself (oil spots, specks). And the effluent system has its own chemistry and often a membrane stage. One product can't be optimized for all three. We match a defoamer to each section instead.
How to Choose
Q:So how do I decide between PR-01A, PR-01B, and PR-01C?
A:Think of them by where the foam is. PR-01A Polyether is the workhorse for the white-water circuit and dirty, strongly acidic/alkaline systems - it holds up in high-COD water and is safe for membrane stages. PR-01B Silicone is for when speed matters: it knocks foam down fast and stays stable at high temperature, and it's the right pick where it contacts coatings or inks. PR-01C High Carbon Alcohol is built for the wet end on high-grade and tissue grades, where the priority is a clean sheet with no residue or specks. All three are non-ionic and free of NP/APEO, so they sit well with the rest of your wet-end chemistry.
Application Pitfalls
Q:Any mistakes we should avoid when applying them?
A:Yes - this is where mills waste product. PR-01A is a high-concentration concentrate: do not dilute it with water. Dilution causes layering and emulsion breaking, kills performance, and raises cost. Add it neat at an easy-dispersion point. PR-01B can be diluted with water but the dilution must be used promptly. PR-01C is diluted with clean water at a ratio we set for your system. Get the addition point and rate right and you avoid the overdosing that plagues single-product use.
Results & Paper Quality
Q:What results should we see, and will it affect sizing, dyeing, or strength?
A:Stable foam control at each point, no specks on high-grade paper, and lower overall defoamer consumption. PR-01A does not adsorb onto AKD/ASA sizing agents, dyes, or retention aids, and does not destabilize emulsions or change Cobb values or paper strength - so paper quality is unaffected. The three-product approach gives matched foam control across the full line instead of one product fighting every condition.
If your mill is fighting foam at multiple points or seeing defoamer residue on finished paper, our technical team can map a defoamer plan to your specific machine and grades.
