Foam develops during the manufacture and application of many types of waterborne coatings, inks and adhesives. Heads of foam, which are caused by mixing and grinding, or that develop during automated filling operations, increase production time and lower the output of the manufacturing process. During application, entrained air and foam are also the causes of undesirable surface defects such as craters, fisheyes and pinholes. For these reasons, the incorporation of a defoamer is important in many waterborne products.
To control the formation of foam during the pigment grinding process, 100% active defoamers are commonly employed due to their ability to withstand the high shear forces applied. This is especially true when the viscosity differential between the defoamer droplets and the foaming medium is large. Care must be taken when selecting a defoamer for the grind operation, because the shear forces can reduce the defoamer droplets to a size too small to be effective, resulting in a marked loss of defoaming efficacy.
By contrast, in situations where gentle stirring is typically employed, notably when sensitive binders are used, or when adding to the letdown, or when the defoamer is to be added to the finished product, the addition of a water-based defoamer emulsion may be preferred. Defoamer emulsions are typically supplied in a finely dispersed form, which helps to facilitate their ready incorporation into the paint or coating.
Further, the performance of defoamers can be improved through the incorporation of fine (micron sized) hydrophobic particles such as AMS’s AMSil brand of treated silica, and in many cases the presence of these particles is fundamental to the overall defoaming performance. Foam destruction by this mechanism is called de-wetting, whereby the surfactant film which stabilizes the foam lamella cannot wet the hydrophobic particles and so it pulls away.
Quality Defoamers from AMS
Whether your product is a decorative matt paint that responds well to a traditional mineral oil-based defoamer, or a high-gloss architectural paint that requires an organo-modified siloxane defoamer, Applied Material Solutions (AMS) manufactures an array of products across the spectrum of defoamer chemistries. Our products are sold in packages ranging from 5-gallon pails to bulk tank wagons.
In addition to antifoams and defoamers, AMS offers a range of value-added services, such as:
- Private labeling for companies reselling defoamers
- Drop shipping
- Toll manufacturing
- Customized formulation
Contact us today to learn more about our products and services.