FORMING HANDSHEETS FOR REFLECTANCE TESTING OF PULP (SHEET MACHINE PROCEDURE)

This practice describes the procedure using the TAPPI sheet machine for preparing reflectance-testing specimen sheets of bleached or unbleached pulp whose fibers are readily dispersed in water. This practice permits the preparation of sheets having a smooth and reproducible surface for reflectance measurements with a minimum of washing or contamination of the sample.

The pulp sample slurry is adjusted to a pH of 6.5 ± 0.5.

TAPPI Standard Practice T 218 describes a procedure for using the Büchner funnel for making handsheets for the same application. The purpose for having two practices is discussed in sections 4.3 and 4.4.

See Appendix for consideration of recycled pulps.