Defoamer for Pulp | Foam Control for Pulp Washing & Black Liquor
Why Use a Defoamer for Pulp?
In the pulp and paper industry, foam hits efficiency hard. In washing, screening, bleaching, concentration, and black liquor recovery, foam causes fiber loss, lower pulp quality, higher chemical use, and downtime.
A good defoamer keeps the line running, improves pulp quality, and cuts cost. INVINO® modified silicone emulsion defoamers hold up in high-alkali black liquor and hot washing without breaking down — so they keep suppressing foam where ordinary products fail.
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How a Defoamer Works in Pulp & Black Liquor
Defoamers break down the foam that builds up in pulp processing — especially in black liquor recovery, where foam hurts performance most. INVINO silicone defoamers give long-lasting, consistent foam control across pulping stages.
Silicone emulsion droplets cut surfactant foam that causes sheet defects, improving web uniformity and tensile strength of the finished paper.
The emulsions stabilize the pulping loop, preventing pipeline air locks and vacuum interruptions caused by dense black liquor foam.
Stable silicone actives keep foam down at low dose, cutting the need for extra surfactant and lowering mill operating cost.
Recommended Defoamers for Pulping & Black Liquor
Silicone defoamers calibrated for high-alkali pulp washing and black liquor concentration:
| PRODUCT CODE | CHEMICAL TYPE | ACTIVE SOLID (%) | Application / Best For | TECHNICAL FILES |
|---|---|---|---|---|
| INVINO-6830 | Silicone Emulsion (Modified) — Standard | 30.0±1.0% | Sulfate kraft wood pulp loops, brownstock washing lines, and high-shear screen extraction. | DOWNLOAD TDS |
| INVINO-6930 | Silicone Emulsion (Modified) — Upgraded | 30.0±1.0% | Multi-effect vacuum evaporators, high-gravity black liquor concentration, and heavy thermal shock. Upgraded version of INVINO-6830. | DOWNLOAD TDS |
Why Choose INVINO's Defoamer for Pulp?
- Strong foam control: Modified silicone actives keep working under continuous high heat and strong alkali.
- Technical support: Free lab cross-matching and on-site trials to solve your specific foam problem.
- Low dosage: Efficient foam knockdown at low dose keeps chemical use and impact down.
Technical FAQ for Pulp & Black Liquor
Q: Is the defoamer stable in strong alkaline black liquor?
A: Yes. INVINO-6830 and 6930 are modified silicone emulsions built to stay stable in high-alkali kraft black liquor and hot washing, where ordinary emulsions break down.
Q: Will the silicone defoamer leave spots on the pulp or paper?
A: No. The emulsions are cross-link stabilized, so they disperse uniformly and do not oil out, avoiding silicone spots on the sheet during washing and forming.
Q: Can it handle the heat in multi-effect evaporators?
A: Yes. The upgraded grade INVINO-6930 is calibrated for multi-effect vacuum evaporators and high-gravity black liquor concentration under heavy thermal shock.
Q: What is the difference between INVINO-6830 and 6930?
A: INVINO-6830 is the standard grade for brownstock washing and screening. INVINO-6930 is the upgraded version with stronger persistence for evaporation and high-concentration black liquor. Both are 30% active silicone emulsions.
Q: Where should the defoamer be dosed in the pulp line?
A: Dose continuously at the washer feed, screen room, or before the evaporator — ahead of the high-foam stage — using a metering pump. We confirm the exact point from your free lab trial.
Request Your Pulp Defoamer Solution
Standard Protocol for Pulp Sample Verification
System Parameter Submission
Share your feedstock (hardwood/softwood), black liquor solids, washing-stage shear, and operating pH.
Free Lab Test (Hot Black Liquor Recirculation + Alkali Stability)
Our lab runs a 90°C high-shear black liquor recirculation and alkali-stability check to match a spot-free grade — free of charge.
Free Sample Dispatch
Free trial samples ship via air express for brownstock washer and evaporator trials. No MOQ at sample stage; buyer covers freight, refunded on the first bulk order.