PROGRAMME FOR ENVIROCELL 2-DAY SEMINAR

WET END CHEMISTRY FOR PAPERMAKERS

This two day seminar is for anyone wanting an in-depth treatment of paper chemistry,
particularly that taking place at the wet end of the paper machine. The notes
accompanying this seminar provide a comprehensive document for reference purposes. This seminar was presented at the 2001 annual congress of the Technical Association of the Brazilian Pulp and Paper Industry (ABTCP) to an audience of about 70 people with simultaneous translation into Portuguese.

PROGRAMME

Introductory background and fundamentals
- definition and scope of wet end chemistry
- colloid chemistry (adsorption, flocculation and charge effects)
- wet end interactions, retention and drainage

Raw materials: chemistry, effects and interactions
- fresh water
- virgin and recycled pulps
- mineral fillers and pigments
- retention and drainage aids
- sizes (rosin, AKD and ASA)
- dry strength additives (starches, polyacrylamides, gums)
- wet strength additives (UF/MF resins, polyamide resins, etc)
- colorants (pigments and dyes) and fluorescent brightening agents

Control of problematic substances
- pitch and stickies
- slime and other microbiological effects
- foam and entrained gases
- interfering materials (anionic trash)

Measurement, monitoring and control techniques
- sampling and laboratory simulators (dynamic drainage jar)
- off-line measurement techniques

pH, temperature, conductivity, aluminium, calcium, sulphate, COD, carbohydrate, starch, lignin, organic acids, zeta potential, streaming current/potential, colloid titration, consistency, ash, etc)

- on-line monitoring (consistency, charge, flocculation) and integrated on-line
monitoring and control systems and strategies.

Practical wet end chemistry of paper/board machines
- wood-containing papers (newsprint, SC, LWC)
- wood-free fine papers and coated papers
- packaging papers/boards
- tissues and towels
- papers based on recycled fibre.