Alkyl Ketene Dimer (AKD Wax) CAS 144245-85-2

What AKD Wax Is

AKD wax is the solid raw form of alkyl ketene dimer, sold as pale yellow waxy flakes. It is not dosed straight into a paper machine. The flakes are first melted and emulsified into a stable aqueous dispersion, and that AKD emulsion is what goes into the wet end. In the dryer section the particles melt onto the fibers and react with cellulose to form a permanent bond, turning the hydrophobic alkyl chains outward so the finished sheet resists water instead of simply coating it.

AKD vs Rosin Sizing

AKD and rosin are the two mainstream internal sizing routes, and they work on different principles. AKD reacts with cellulose under neutral to slightly alkaline conditions, gives a permanent water-resistant bond, and runs happily alongside precipitated and ground calcium carbonate fillers that lift brightness and let the sheet carry more filler. Rosin sizing needs an acidic system with alum, costs less, but can yellow the paper and corrode the wire and dryer parts over time. AKD is the usual choice for bright, archival and filler-loaded grades.

Papers and Boards Sized With AKD

• Printing and writing paper. Copy, offset and notebook grades get even ink holdout, clean edges and stable brightness for long storage.
• Food contact board. Cup stock, folding carton and baking paper gain a moisture barrier without acidic migration, with food-grade formulations available.
• Packaging and specialty paper. Kraft wrapping, corrugating medium and decorative stock hold their strength and dimensions in humid handling and storage.

Standard Flake Grade Specifications

Storage, Packaging and Ordering

• Keep the flakes sealed below 30 °C, away from steam pipes and direct sun. Heat above 40 °C makes the ketene groups self-polymerize and quietly kills sizing activity, so rotate stock first in, first out.
• The wax is non-hazardous for normal ocean and land transport. Waxy dust can irritate skin and airways, so wear gloves and a dust mask when handling bulk flakes, and clear spills before they melt into a slip hazard.
• Packaging: 25 kg PE-lined kraft bags and 500/1000 kg bulk bags. COA, TDS and SDS come with every order, samples are available, and quotes go out within one working day. Related wet-end chemicals: Cationic Starch CAS 56780-58-6 and Polyamide Epichlorohydrin (PAE) CAS 68583-79-9.

FAQ

Q: AKD or rosin for neutral sizing?

A: AKD fits neutral, carbonate-loaded sheets; rosin needs acidic alum and costs less.

Q: Can the wax flakes go straight into the pulp?

A: No, emulsify the flakes first; the AKD emulsion is what enters the wet end.

Q: How should AKD wax be stored?

A: Sealed below 30 °C; sustained heat over 40 °C self-polymerizes it and kills activity.