AKD Emulsion


AKD Emulsion

. Overview
AKD neutral sizing agent is a kind of white emulsion emulsify acquired by homogenizing process with alkyl ketene dimer (AKD) and cationic surface active agent as raw materials, also a reaction papermaking sizing agent suitable for alkaline (pH value 7.5 ~ 8.5 ) papermaking condition. It is widely used in the production of sized paper like various middle and top grade cultural papers, photographic paper, fruit bag paper, packaging paper and paperboard, etc..
. The Sizing Mechanism

The cationic, AKD particles, in the emulsion will remain on the fiber surface by means of unit or dual retention system like a cationic starch, polyacrylamide, etc. After the press and the initial drying phase, AKD particles melt and spread uniformly on the fiber surface and redistribute, forming the highly oriented monomolecular layer. At drying and storage phases, it will experience esterification reaction with the hydroxyl groups on the fiber molecule and firmly bonded to the fibers, with hydrophobic long-chain aliphatic group steering to paper surface, so as to achieve excellent water-resistant results.
. Features

(1).Significantly improve paper strength, toughness, whiteness and opacity. Improve the printability of paper.
(2). Give papers good optical properties, chemical stability and long shelf life. The paper is not easy to turn yellow.
(3). High tolerance for calcium carbonate filler (10 ~ 30%), saving fiber raw materials and reducing slurry consumption.
(4).Without aluminum sulphate, white water soluble solids greatly reduced, Whitewater lockable cycle, reduce environmental pollution, water conservation.
(5).As the alkaline papermaking condition, the device can be reduced corrosion, extend the service life of mesh fabric and felt.
(6). Small bubbles, no dirt, and clean the wet end system to improve runnability. 
. Technical Indicators

Items Indicator
Appearance White emulsion
Solid content 10±0.5, 12±0.5, 15±0.5, 19±1%
PH value 34
Ionic Cationic
Density 1.01
Dispersion Dispersible in cold water
Stability 90 days25棩
. Method of Application

(1). Diluting the AKD emulsion to a concentration of 3 to 4 percent and add into the slurry tank, or with a metering pump continuously added to the mixing tank , high box or slurry pipe , in general, adding tune headbox best.
(2). Reference dosage: cultural paper 0.07 to 0.3% (pure), fruit bag paper 5 to 7% (pure)
(3). AKD emulsion must be used for comply with cationic starch, polyacrylamide and other units or dual retention system. Adding sequence is generally: cationic starch → AKD → polyacrylamide. Quaternary ammonium type cationic starch as the degree of substitution > 0.015 , a concentration of 1% , the addition of 1 to 1.5 %, polyacrylamide ions and cationic both can work, molecular weight of 5 to 8 million, a concentration of 0.1 to 0.2 % is appropriate, add the amount to 2% of cationic starch, generally is 150 ~ 250ppm.
. Notes

(1). Control the pH value of head box of 7.5 to 8.5, such as less than 7.5 can be added soda adjustment. Total alkalinity being 150 ~ 250ppm of AKD sizing efficiency can be improved to shorten the curing time.
(2). Zeta potential control headbox between the -3 ~ 5mv can increase first pass retention and AKD sizing efficiency.
(3). Higher drying temperature can increase curing rate of AKD sizing efficiency, so increasing the drying temperature not lower than 95 is important.
(4). AKD is best to use fresh emulsion with storage period of 30 days or less being best.
(5). When replaced the acidic papermaking condition with the alkaline one, shall thoroughly clean the equipment and piping.
. Packaging, Labeling, Storage

(1). Packaging the products using plastic barrel, with net weight 200kg or 1000kg per barrel.
(2). The barrels shall have the following signs: product name, model number, manufacturer name, batch number, net weight, production date, product certification, and stamped with the seal of inspection.
(3). Product shall be stored in a cool place (5 ~ 30 ), and shall not be open-air exposed, frozen.