Studies of the influence of deflocculants and flocculants on the refining efficiency on a pilot scale

• The objective of the present investigation was to study the influence of flocculants and deflocculants on refining efficiency. The refining was performed with the aid of a conical refiner at EuroFEX, and the refining response was evaluated as the change in fibre properties and in the mechanical properties of handsheets. Using the same furnish, an unbleached never-dried softwood pulp, the effect of fibre dimensions on floe strength was excluded as much as possible. The degree of flocculation was changed by addition of APAM, CPAM, guar gum and CMC. The floe strength was characterized using a parallel plate rheometer. The added chemicals, except for APAM, affected the relation between power input and gap clearance. To reach a certain power the fibres treated with guar gum, CMC or CPAM required a narrower gap clearance than the reference pulp or when APAM was added to the fibres. Refining at a narrower gap clearance increased the refining efficiency in terms of WRV and paper property development, as long as fibre length reduction could be avoided.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Pappers-, massa- och fiberteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Paper, Pulp and Fiber Technology (hsv//eng)

Nyckelord

Beating

Refining

Kraft pulps

Mechanical properties

Swelling

cellulosic fibers

topochemical modification

carboxymethyl cellulose

paper strength

pulp

papermaking

attachment

surface

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)