Sheet quality is not one additive. Formation, dust, cylinder tack, and first-pass retention fail for different reasons. Esteem’s paper sheet-making aids table is two grades: VENPAPER SC 1 for fiber dispersion and handle, and VENPAPER AST as a flocculant-cum-retention aid. Specify the mill complaint, then pick the chemistry.
What “Paper Improvement” Means on the Machine
Procurement pages often lump retention, drainage, and “quality” into one SKU. On the wire, the jobs split. Poor fiber distribution shows as wild formation and lint. Low retention shows as filler in the save-all, cloudy white water, and a sheet that will not hold ash. Cylinder tack and dust are often a surface/fiber-bond problem, not a missing polymer. Esteem’s paper chemicals improvement page lists only the two published grades—do not invent AKD, starch, or dry-strength resins that are not on that table.
Esteem Grades by Sheet Job
| Grade | Role | When to start here |
|---|---|---|
| VENPAPER SC 1 | Fiber-dispersion sheet-making auxiliary | Formation, cylinder tack, soft handle, dust/fluff on the machine |
| VENPAPER AST | Flocculant-cum-retention aid | Fines and filler leaving in white water; first-pass retention too low |
Fiber Dispersion vs Flocculation
SC 1 is written as an aid to better sheet making by dispersing fibers, reducing tackiness on the cylinder, giving a softer handle, and cutting dust and fluff. That is a formation and runnability brief. AST is a flocculant-cum-retention aid: it is meant to gather fines and filler so they stay in the sheet. Using a retention polymer to “fix dust” can over-flocculate and make formation worse. Using a dispersant when the mill is losing 20% of its GCC to the sewer will not close the ash gap.
Charge and shear matter. After the fan pump, flocs see high shear; the polymer that worked in a jar may need a different addition point on a fast machine. Record consistency, pH, filler type (GCC, PCC, talc, clay), and any existing cationic starch or dual-polymer program before you change AST dose.
How Retention Interacts with Sizing, OBA, and Foam
A strong flocculant can drag size, dye, and optical brightener with the fines. If Cobb or shade shifts when you raise AST, you are not looking at a “bad retention aid”—you are looking at wet-end balance. Keep the sizing guide and bleaching / OBA guide in the same trial notebook.
Dirty white water also foams. Do not raise defoamer to hide a retention hole; fix solids first, then trim foam with the paper defoamers guide.
Two Published Grades, Two Failures
The sheet-making table (the mill URL keeps the historic spelling paper-improvment) lists VENPAPER SC 1 and VENPAPER AST only. Do not invent AKD, starch, or dry-strength resins onto this page—those jobs sit on sizing. SC 1 is the fiber-dispersion auxiliary: better sheet making, less cylinder tack, softer handle, less dust and fluff. AST is the flocculant-cum-retention aid: fines and filler stay on the wire instead of circulating in white water. First-pass retention, ash retention, and clearer white water are AST payoffs. Formation look-through, yankee stickiness, and lint are SC 1 payoffs.
Retention and drainage are related, not identical. Over-flocculation can speed drainage and wreck formation. Under-dose leaves fines in the loop. Using AST to “fix dust” can over-flocculate. Using SC 1 when the mill is losing GCC to the sewer will not close the ash gap. Charge and shear matter. After the fan pump, flocs see high shear; record consistency, pH, filler type (GCC, PCC, talc, clay), and any existing cationic starch or dual-polymer program before you change AST dose.
Wet-End Balance: Size, OBA, Felt, Foam
A strong flocculant can drag size, dye, and optical brightener with the fines. If Cobb or shade shifts when you raise AST, that is wet-end balance, not a “bad retention aid.” Keep the sizing and bleach/OBA programs in the same trial log. Dirty white water also foams. Do not raise defoamer to hide a retention hole; fix solids first, then trim foam.
Dust and holes can also come from filled felts. Watch felt vacuum on the same run as FPR. Clothing and air can mimic “poor quality.” Name the mill complaint in mill language—formation, dust, cylinder tack, first-pass retention, or ash in effluent—then request SC 1 and AST as two jobs from the sheet-making table, not one “quality chemical.”
What a Sheet-Making Trial Must Record
Write the mill complaint in mill language before you order. Formation, cylinder tack, dust, and fluff point to VENPAPER SC 1. Low first-pass retention, dirty white water, and ash in effluent point to VENPAPER AST. Record furnish, filler type (GCC, PCC, talc, clay), consistency, pH, machine speed, current retention polymer if any, FPR, white-water solids, Cobb, and lint. A jar that looked good may fail after the fan pump. If Cobb or shade moves when you raise AST, log size and OBA on the same sheet. If vacuum is gone, check felt fill before you blame the retention aid.
How to Specify with Esteem
- Name the complaint in mill language: formation, dust, cylinder tack, first-pass retention, or ash in effluent.
- Share furnish, filler, machine speed, and current retention/drainage chemistry (if any).
- Give baseline numbers you already measure (FPR, white-water solids, Cobb, lint).
- Trial SC 1 and AST as separate jobs from the sheet-making product table.
- Watch felt vacuum and foam on the same run—clothing and air can mimic “poor quality.”
Related mill chemistry: felt cleaning, sizing chemicals, and dispersing agents when filler slurry stability is the real issue.
Contact Esteem for mill samples, or custom synthesis when a dual-polymer window is not in the catalogue.