Antifoam products allow controlling the presence of unwanted foam in different processes, including the manufacture and application of paints.

One of the most critical foaming steps in paints is the grinding phase. During the grinding of paints, equipment that generates high shear forces is used in order to obtain a homogeneous distribution of the particle size of the fillers. Although the equipment is usually designed to reduce foaming, some entrapped air is unavoidable. Another phase where foam tends to cause deviations in the production system is during packaging, where the decrease in the density of the paint, meaning the relationship between its volume and its weight, causes that the weight specifications cannot be reached due to excessive air content. Additionally, during the application of paints, especially if applied with high-shear applicators, such as spray guns or foam rollers, these promote the incorporation of entrapped air in the paint that can cause surface defects in the coating, such as craters, pinholes or reduced gloss.

The usual approach to solving foam problems generally involves selecting the appropriate antifoaming agent. The optimal antifoam is frequently established based on the characteristics of the process, the formulation, and the type of foam generated in the paint, whether it is macro or micro foam.

Traditionally, mineral oil-based antifoams with hydrophobic foam-destroying particles have been used in the paint industry. This class of antifoams are mainly the ones that offer the best ratio between antifoaming effectiveness and cost, these two criteria being the ones that often turn out to be the most important when choosing the antifoam. However, there is a growing tendency to consider ecological criteria as a fundamental requirement in the selection of raw materials.

 In 2004 the European Union passed the 2004/42/EC paint directive, limiting the presence of volatile substances in paints, varnishes, and vehicle finishes. In 2014, it established the criteria for obtaining the ECOLABEL, with which the final consumer is guaranteed that paints and varnishes with this label will have a minimum content of toxic substances, as well as a minimum content of volatile and semi-volatile organic compounds (VOC and SVOC). This label is an assurance of paints and varnishes efficacy when used indoors and / or outdoors.

For this reason, at CONCENTROL we have designed a new range of mineral oil-free antifoams, which are not harmful to humans or the environment due to their low or no toxicity, and the enhanced biodegradability of the raw materials. They have been designed with a zero content of VOC and SVOC (volatile and semi-volatile organic compounds) emission gases that can pollute air quality and be harmful to the atmosphere. In addition, from the point of view of efficacy, they improve antifoaming effectiveness compared to traditional antifoams based on mineral oils. Plus, the new range of antifoam agents, comply with the European Union regulation 10/2011 which list the allowed raw materials to be used in materials and plastics for food contact applications. Making them a suitable and compliant option for applications such as coatings intended for food packaging.

In short, they are antifoams designed to be the best in terms of quality/cost/ecology ratio.



The new range of environmentally friendly antifoams EMULTROL DFM is made up of the following references, which are compared in the following table with two traditional antifoams based on mineral oils.

Antifoam Base composition Solids (%)
EMULTROL DFM OLM-17 Mineral oils 100
EMULTROL DFM AFO-1 Mineral oil emulsion 55
EMULTROL DFM OLV-24 Vegetable derived oils 100
EMULTROL DFM AFO-24 Vegetable derived oils emulsion 55
EMULTROL DFM OLV-25 Ecological oils 100
EMULTROL DFM AFO-25 Ecological oil emulsion 55

The new formulated antifoams EMULTROL DFM OLV-24 and EMULTROL DFM AFO-24 are based on vegetable oils and the newest EMULTROL DFM OLV-25 and EMULTROL DFM AFO-25, are based on ecological oils. In the experimental part, furtherly performance tests will be shown to verify how these new formulations performance in efficiency as antifoam and compatibility in test paint applications. High quality raw materials have been chosen to ensure that the formulation, as a whole, can be used in the most sensitive applications, such as the formulation of paints and coatings suitable for food contact. In addition, its composition is optimal to be used in paints and coatings that seek to comply with the most demanding ecological certifications, such as ECOLABEL or Nordic Swan.


Comparative study

To evaluate the antifoam efficacy of these new products, effectiveness, stability and compatibility tests have been carried out in Concentrol’s application laboratories, using as test medium, standard water based polymeric dispersions of the paints and coatings industry, such as styrene-acrylic polymer, acrylic, vinyl-veova, and ethylvinylacetate. 

Dispersion Solids (%) pH MFFT (ºC)
Styrene acrylic copolymer 50 6,5 – 8,5 22
Acrylic copolymer 48 7,5 – 8,5 14
VeoVa® vinyl acetate copolymer 55 4,0 – 5,0 15
Ethylvinylacetate polymer 60 4,0 – 6,0 2


Antifoam performance test 

To evaluate the antifoam performance, a 200 ml sample of polymeric dispersion is taken in a beaker, 0.2% of the antifoam to be tested is added, a stirring process is undertaken at 1300 rpm for 5 minutes. The percentage of entrained air is obtained by calculating the difference in the measured density between the initial density of the dispersion and its final density after the test. The preparation is aged in an oven at 45 °C for one week, afterwards the test is repeated to determine the performance stability of the antifoam during the aging. This last process, allows us to evaluate the stability of the antifoam effect throughout the shelf life of the paint.


Results and discussion

Furtherly results of the antifoaming performance tests in the different test media are shown. A lower % of entrained air indicates a greater antifoam effectiveness. 

Figure 1. The results of the antifoam effectiveness tests on 4 standard water based polymer dispersions of the paints and coatings industry are shown, showing both the effectiveness of the fresh test (blue) and the test after the aging of the polymer dispersion (orange).


It can be seen that ecological antifoams show a better performance in terms of antifoam effectiveness than traditional antifoams. In polymeric dispersions such as styrene acrylic they can de-aerate between twice and three times as much entrained air as traditional antifoams. It is observed that the references EMULTROL DFM OLV-24 and EMULTROL DFM AFO-24 present an increased persistency of the antifoam effect against aging. While the EMULTROL DFM OLV-25 and EMULTROL DFM AFO-25 references show a slightly better immediate antifoam performance, despite their aged performance is comparatively worse.

Antifoam compatibility test

The compatibility of the studied antifoam preparations with the different polymer dispersions is evaluated, in order to verify that the antifoam does not cause quality problems such as fish eyes, craters or orange peel in paint application. For this purpose, an application of the preparations of polymer dispersions, with a Mayer-type spiral bar, of 25 micrometers depth, on a LENETA® cardboard support, has been tested.

Figures 2, 3, 4 and 5 show the compatibility tests of the polymer dispersions, showing examples of each of the new references in comparison with their traditional antifoam equivalent. It can be seen that the finished coatings containing antifoams are generally better or similar to the finish of the control test. A trend is observed where preparations with less entrained air % show a better coating and levelling, resulting in a more homogeneous finish.

Figure 2. Compatibility test in dispersion of styrene acrylic copolymer6.



Figure 3. Compatibility test in acrylic copolymer dispersion6.



Figure 4. VeoVa® vinyl acetate copolymer dispersion compatibility test.



Figure 5. Ethylvinylacetate polymer dispersion compatibility test.



A new range of ecological antifoams has been developed, as an alternative to mineral oil based antifoams, showing an equal or better antifoaming performance for applications in architectural paint formulations. In addition, they have an excellent compatibility with most of the standard paints on the market. And last but not least, they are designed for the most sensitive applications, fulfilling the most demanding ecological and food standards in the paint and coatings sector.

Come and learn about these solutions at stand 3A-220 of the ECS2023 exhibition from March 28 to 30.