Cardboard, e.g. for laminated or corrugated cardboard etc.

摘要

A multi-sheet board, esp. for corrugated board, has one of its internal sheets composed entirely of activated sludge, such that the paper contains 85-99.5% of raw fibre and 0.5-15% of sludge. Formation of a sludge layer on top of a wood pulp layer avoids loss of sludge particles into the back water. (Russion Inventors Cert. 440468). The sludge is a cheap raw material. Further, the paper may also contain a binder and a precipitant. The required quantities of these are reduced by the pressure of sludge. (Provisional Basic previously advised in Week E44).