PREPARATION OF THERMAL INSULATING BOARD FROM WASTE EFFLUENT OF A PAPER PULP MILL

摘要

1386299 Thermal insulation board GREFCO Inc 12 Sept 1972 [5 Oct 1971] 42356/72 Heading D2B Thermal insulation board is made at least in part from paper pulp waste effluent material which has been treated to adjust its pH value to between 5 and 7 and screened to remove particles of size greater than 4 mesh. (U.S.S.). The paper pulp waste effluent material may be used in combination with pulp fibres such as repulped newsprint or refined Kraft process pulp. Perlite, asphalt, waxes, rosins, and silicones may also be incorporated in the board. The board may be made by a conventional wet-laying process e.g. a Fourdrinier process. pH adjustment may be effected using alum alone or in combination with sulphuric acid.