Draw the addition sequence
Mark every component, dilution, addition point, stock consistency, delay and shear element before the headbox.
The process map is the test recipe.
Measure furnish charge
Record conductivity, pH, cationic demand or the mill's charge-control signal before chemical addition.
Charge variability can change which component is limiting.
Prepare every component
Use realistic concentration, dilution water, aging and solution age for each polymer or microparticle.
Incomplete preparation can invalidate a system comparison.
Keep sequence intact
Add components in the actual order and preserve contact time between them.
Do not mix all additives together for laboratory convenience.
Apply staged shear
Measure the response before and after fan-pump and pressure-screen-equivalent shear.
Observe whether the later component provides useful reflocculation.
Collect balanced metrics
Track total and ash retention, drainage, white-water solids, formation and target paper properties.
A dual system must outperform its added complexity.
Test contamination windows
Repeat the shortlist at credible high conductivity, high fines or high broke conditions.
Define whether a coagulant or charge-control adjustment is required.
Write the control plan
State component ranges, sequence, monitoring points, response rules and requalification triggers.
Preserve every approved product identity with the trial record.
Machine-trial interpretation and release record
A useful paper-machine decision record connects the product question to a defined furnish and grade. Record fiber mix, fines, filler, broke, pH, conductivity, temperature, charge demand and the complete wet-end additive sequence. Identify the current limitation and the measurement that will decide the trial. This context prevents a visually attractive laboratory result from being mistaken for a production-ready recommendation.
Compare a blank, the current program and coded candidates at equal active addition. Keep stock consistency, dilution water, polymer aging, addition order, mixing energy and elapsed time consistent. Measure the relevant combination of total and ash retention, drainage, white-water solids, formation and sheet properties. Repetition matters when furnish variability is large, and an apparent improvement should remain visible against the reference before scale-up.
The machine review should trace polymer from make-down to the headbox or selected sheet-strength addition point. Note feeder calibration, stock concentration, aging, dilution, injection hardware, contact time, fan-pump and screen shear. A chemistry that works only under gentle beaker mixing may not survive the approach-flow path. Conversely, poor wetting or a blocked dosing line can make a suitable grade appear ineffective.
Approve an operating window, not a universal dose. State the furnish, paper grade, test methods and acceptable balance among retention, drainage, formation, runnability and finished-paper quality. Link the approved sample code to its quotation, COA, SDS, packaging and receiving checks. Revalidate after meaningful changes in furnish, filler, wet-end chemistry, addition point, machine speed or supplied product identity.
Plan the machine trial before the sample arrives. Define baseline duration, sampling points, laboratory methods, operator observations, stabilization time and stop conditions. Hold other additives steady when practical, and document every unavoidable process change. Review white water, press behavior, deposits, broke and finished-paper tests beside the primary metric. A trial succeeds only when the total process and quality balance remains acceptable, not when one retention or drainage reading briefly reaches a peak.
Close the work with a release sheet that production, quality and purchasing can all use. Include the accepted product code, active addition range, preparation recipe, addition point, monitored signals and corrective actions. Add the representative furnish window and approval date. This lets later lots be checked against the same evidence and prevents a result from being separated from the conditions that created it.