Wax dispersion during recycling of old corrugated containers

Bales of old corrugated containers (OCC) often contain a small percentage o f wax-coated boxes. During the recycling process, the petroleum waxes are d ispersed in the furnish, leading to runnability problems and diminished she et quality. Laboratory tests were conducted to determine how the thermal pr operties of various waxes affect their behavior in papermaking systems. Res ults show that the mass of dispersed wax is a function of temperature. This relationship is described by a sigmoid curve that climbs only after the on set of the wax's melting transition. Deposit formation was greatest between the end of the waxes' solid-solid phase transition and its melting point. These lab results guided the development of a new dispersant that reduces t he melting transition of wax coatings. Testing shows that the new dispersan t substantially improves the breakdown and stabilization of wax contaminant s at temperatures typically used for repulping OCC. The dispersant can be u sed with poly-electrolyte coagulant as part of a two-step contaminant contr ol strategy in which the wax is first broken down into a stable colloidal d ispersion and then removed by coagulating the colloidal particles with the fiber at a clarifier or on the fiber line.