Domtar Inc.

John R Wood

Alkibiadis Karnis

Joseph B Beaulieu

A method and apparatus for determining the consistency of pulps by squeezing the pulp in a press and registering the pressure required to initiate the flow of water from said pulp, said pressure being indicative of the consistency of the sample.

Measurement of high consistency

Process for producing a mechanical pulp of improved linting properties by screening the pulp to provide a through and a retained fraction, fractionating the through fraction by means of a hydrocyclone into at least two fractions one fraction having an average specific surface less than a predetermined value between 1.2 and 4 m.sup.2 /g and the second fraction having an average specific surface greater than the first fraction and subjecting the first fraction to mechanical processing thereby to form a processed fraction having an average specific surface of 4 to 10 m.sup.2 /g and recombining said process fraction and said second fraction into a combined pulp. The invention also relates to a method of determining specific surface distribution of fibres of the mechanical pulp by fractionating the pulp in a hydrocyclone system into a plurality of underflow fractions and a plurality of overflow fractions each of said underflow and overflow fractions containing a different portion of fibres of said sample and analyzing each of said underflow fractions or of said overflow fractions or both to determine the specific surface of each of said selected underflow or overflow fractions.

Bonding properties of mechanical pulps

A method and apparatus for determining the fractional distribution of fibers by specific surface in a sample of mechanically treated pulp comprising: a hydrocyclone, at least two collecting chambers, a pump to feed pulp to said hydrocyclone, means to selectively connect the pump inlet with each chamber and means to selectively connect one of the outlets of the hydrocyclone to a selected chamber.

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Dorion, Canada

John R Wood