Sep 27, 2016
The amount and effectiveness of thedefoamer depends on the formulation system of the coating or ink, in particularthe type of polymer, the pH, the amount of pigment used, and the chemicalstructure of the other adjuvants used. Similarly, the manufacturing process and construction process onthe type and amount of defoamers are also required.
The addition of a method to distinguishdefoamer products from defoamer emulsions and defoamer concentrates isdiscussed. Defoamers Emulsiondroplets of emulsion products have been dispersed into the desired sizedistribution in the product delivery. It can be added in the mill or in the paint setting process, andcan be easily mixed in the coating or ink. For defoamers which do not contain hydrophobic solid particles,they can even be added by stirring in the lacquer.
The addition of the defoamerconcentrate containing 100% of active material directly affects theeffectiveness of the antifoam agent. The particle size distribution obtainedduring the addition stage determines its antifoaming effect. For this purpose,defoamer concentrates are usually added to the milling base Material.
Defoamers are added to the system withhigh shear, but excessive shear forces weaken the defoaming effect. Defoamer over-dispersion and poordispersion, are not conducive to the effectiveness of defoamers play, adddefoamer when using a relatively low shear force, the initial defoaming effectmay be good, but after the storage phase, defoaming The effect of the agent maybe reduced.
In general, defoamers are designed tobe used in the state of supply. If the shear force is insufficient when added,the defoamer of 100% active can be pre-diluted with alcohol or coalescent. The dilution ratio is in the range of 1:1 to 1: 9 dilution for defoamers to facilitate the addition and improvement ofthe size distribution of defoaming particles. This will help to improve defoaming efficiency and reduce thetendency of shrinkage. Pre-dilutionof defoamers will generally reduce the long-term stability of the antifoamactives and hence the storage stability of the defoamers after dilution.