Deinking is a surface-chemistry problem, not a bleach problem. If ink stays bound to fiber, no amount of downstream bleaching aid will deliver brightness. This guide maps Esteem de-inking chemicals to flotation, washing, stubborn inks, and enzyme-assisted loops used in Indian and export recycled-fiber mills.
What Deinking Chemicals Must Do
A working deinking package does three jobs in sequence: wet and penetrate the ink film, detach particles from cellulose, then keep them hydrophobic enough to leave with froth—or hydrophilic/dispersed enough to leave with wash filtrate. Fail any step and specks, low brightness, or stickies deposits follow.
Furnish decides the brief. Old newsprint (ONP) inks are relatively easy. Magazines, UV coatings, and laser toner need stronger detergency. Mixed office waste often needs both a collector and a dispersant. Start from the paper chemicals hub, then pick grades from the de-inking product table.
Flotation vs Wash Deinking
Flotation cells need a measurable, brittle foam. The surfactant must collect ink without stabilizing so much froth that fiber yield collapses. Wash deinking wants the opposite foam profile: ink must stay dispersed and leave through the mat. Mills with both stages often use a higher-froth collector in flotation and a more dispersing grade—or a dedicated paper defoamer—before the machine.
| Grade | Primary job | When to start here |
|---|---|---|
| VENPAPER DK | Detergency + froth to lift ink | Standard flotation deinking |
| VENPAPER CK/SPRS | Stronger detergency and dispersing | Dirtier furnish, more ink load |
| VENPAPER 7830 | Detergency + froth | Alternate flotation collector |
| VENPAPER DM | Stubborn ink / toner | UV, laser, heavily printed waste |
| VENPAPER DZ | Auxiliary without flotation | Wash-only or no flotation cell |
| VENPAPER ENZ | Deinking enzyme | Fiber release support with surfactants |
| VENPAPER SEP C | EO/PO copolymer detergency | When foam must be more controllable |
| VENPAP 6790 | General deinking chemical | Screening trials / mill-specific loops |
Water Hardness, pH, and Stickies
Calcium soap from fatty-acid inks and hardness ions can re-deposit as stickies. If brightness is good but the machine fills with tacky specks, the problem is often water chemistry, not “more deinker.” Check hardness, pH, and whether a dispersing agent or chelant is missing. Felt filling after deinking is a clothing problem as well as a chemistry problem—see felt cleaning chemicals.
Brightness Is Not Only Bleach
Once ink is gone, residual lignin and dyes still need bleaching aids and, on some grades, optical brightener. Do not raise bleach to hide incomplete deinking; you will spend peroxide and still see specks. Sequence: detach → separate → then bleach.
Match the Cell to the Named Grade
VENPAPER DK, VENPAPER 7830, and VENPAPER CK/SPRS are the flotation-side detergency and froth grades. CK/SPRS is the row that also claims dispersing power and stronger detergency for heavier ink load. VENPAPER DM is the stubborn-ink / toner row—UV, laser, heavily printed waste—not a default ONP collector. VENPAPER DZ is the auxiliary for heavily soiled paper on units without flotation; the table says it gives a brilliant sheet when the loop is designed for washing. Do not starve a flotation cell of collector because the machine loop foams, and do not pour a flotation frother into a wash-only mill and call it DZ.
VENPAPER SEP C is the EO/PO copolymer with strong detergency when foam must be more controllable than a high-frothing anionic collector. Related chemistry sits on alkoxylates; this page stays on the deinking table. VENPAPER ENZ is the deinking enzyme: fiber-release support beside the surfactant package, not a household detergent swap and not a bleach. VENPAP 6790 is listed as a deinking chemical for mill-specific loops—keep that spelling on the request.
Carry-Over Foam and Stickies After Brightness
Flotation needs froth; the paper machine loop needs foam killed. Carry-over is a common failure. Use a dedicated paper defoamer downstream rather than starving the deinking cell of collector. Calcium soap from fatty-acid inks and hardness ions can re-deposit as stickies even when brightness looks good. If the machine fills with tacky specks, check hardness, pH, and whether dispersing or chelation is missing—not “more deinker.” Felt filling after deinking is a clothing problem as well as a chemistry problem.
Once ink is gone, residual lignin and dyes still need bleaching aids and, on some grades, optical brightener. Do not raise peroxide to hide incomplete deinking; you will spend H2O2 and still see specks. Sequence: detach → separate → then bleach. Household detergent is not a mill collector. Share waste-paper mix, brightness target, flotation vs wash, water hardness, and pH when you request named VENPAPER grades.
What a Deinking Trial Must Record
Name flotation, wash, or combined before you pick a drum. VENPAPER DK, CK/SPRS, and 7830 are flotation detergency/froth grades; DZ is the no-flotation auxiliary; DM is stubborn ink and toner; ENZ sits beside a collector, not instead of one; SEP C is the EO/PO detergency row when foam must be more controllable; VENPAP 6790 is a mill-specific deinking chemical with that spelling on the table. Record waste mix (ONP, OMG, MOW), hardness, pH, brightness, speck count, and whether the machine loop foamed after the cell. Household detergent is not a mill collector. Do not raise bleach to hide incomplete ink removal. Share those numbers when you request named grades.
How to Specify Deinking Chemistry
- List waste grades (ONP, OMG, MOW, OCC mix) and target ISO brightness.
- State flotation, wash, or combined, plus water hardness and pH.
- Note toner, UV varnish, or adhesive labels in the mix.
- Describe machine-loop foam and stickies history.
- Ask Esteem for a DK/CK vs DM vs DZ vs enzyme starting set, not a single “universal deinker.”
Related guides: paper defoamers, paper sizing, alkoxylates, and nonionic surfactants.
Esteem manufactures deinking surfactants and auxiliaries in ISO-backed plants. Contact formulators for mill trials, or see custom synthesis for a non-catalogue EO/PO window.