Defoamers and antifoamers for solutions of in household chemistry

Excessive foaming during washing, cleaning and rinsing of various materials using solutions of surfactants is very often an undesirable effect. Presence of makes difficult wetting of materials, which results in lower efficiency of washing and cleaning process and extension of the very process.

Where the foam is not desired? of design, by way of adopting special low- foaming surfactants (alcoxylated fatty Washing is readily associated with alcohols) or by adding suitable anti- foaming. Presence of foam in typical foaming agents. household applications of washing and cleaning liquids is a desirable effect. Although addition of low-foaming However in industrial applications of surfactants reduces foaming capacity of detergents, foam is usually a problem, detergents, it requires a series of tests to reducing the efficiency of washing and ensure obtaining required properties. In extending duration of the whole process. addition, such low-foaming surfactants are Examples of such industrial applications much more expensive than standard are washing bottles, cleaning large surfactants. warehouse surfaces, processing of cloths Using antifoamers usually seems to be the (washing, rinsing), degreasing metals, etc. simpler and more cost-effective solution. When added in small doses they do not degrease the wetting properties and do not increase dramatically the recipe costs, while effectively reducing foaming.

Types of defoamers used

Antifoamers and defoamers constitute a large family of auxiliary agents. Depending

on composition they can be divided into How to reduce foaming of detergent silicone, mineral and polymer (organic) solutions? types. However not all of them can be used with detergents. Manufacturers of detergents attempt to minimize the foaming capacity of mixtures as early as at the stage

1 Improperly selected agent can soon lose surfactant. The bubble wall is getting its efficiency in surfactant solution or thinner and thinner, and finally it breaks separate from the detergent. (stages 2 and 3).

Defoamers and antifoamers that worked best in the high concentrated solutions of synthetic surfactants are silicone base types. They have very high antifoaming and defoaming efficiency, as compared with other agents, and their efficiency is not so much dependent on water hardness and temperature.

They can be widely used both with household detergents and in industrial applications.

Composition of silicone defoamers

Active ingredients of silicone-based defoamers are mostly Silica particles (PDMS) with Surfactant particles varying chain lengths. Those substances PDMS are strongly hydrophobic and they feature very high surface activity (surface tension Figure 1 Antifoam mechanism ca. 20mN/m). Their properties allow those compounds to easily reach the border of air and water phases causing damage to Testing of defoamers in detergents air bubbles. Selection of suitable defoamer requires Polydimethylsiloxanes in defoamers are tests to determine if given agent has often accompanied with silica, which antifoaming action suitable for given further improves agent efficiency. Other application, if it spreads well in the ingredients of silicone defoamers - system, without separating during storage, emulsifiers, preservatives and stabilizers and if it preserves it's efficiency in time. ensure stability of defoamer during storage and its ability to spread in the Antifoaming efficiency can be tested using system. Typical concentration of active simple methods, such as shaking, mixing ingredients in is 10 to 50 %. solutions with addition of tested defoamers and observation of their Fig. 1 shows typical mechanism of acting foaming tendency. of silicone defoamer. At the first stage (1) active particles of defoamer surround the gas bubble, displacing the particles of the

2 Efficiency of defoamers is determined in our laboratory with specialised equipment for foaming of water solutions of surfactants by recirculating, pumping, air imjection, shaking and stirring. Adopted method should correspond with conditions of target application.

Tests usually determine the volume of foam generated and foam collapse time, as well as deactivation rate in the solution of given surfactant. Figure 4 Foam generation by perforated disc Photos show the equipment used by in cylinder Rowis-System to perform standard ROMIS silicone defoamers defoamer efficiency tests. The offer by Rowis-System includes silicon-based defoamers and antifoamers in the form of water and concentration of active ingredients in the range 10 – 25%.

They can be used with a variety of liquid detergents based on synthetic anionic, non-ionic and cationic surfactants.

Example applications include:

• cleaning and degreasing fluids Figure 2 Foam generation by recirculation • washing, rinsing and cloth softening liquids

• car shampoos

• industrial cleaning and degreasing baths

• industrial bottle washing (CIP)

• detergent-based sewage • cleaning of tankers and industrial tanks Figure 3 Foam generation by pouring

3 ROMIS silicone defoamers for liquid detergents based on anionic and non-ionic surfactants

ROMIS Application Dose Active appearance Density Shelf live Admissions Ingredients, 3 % % g/cm cP months

Washing and rinsing fluids, White Contact with S-24 Cleaning and degreasing baths, 0.001 – 0.1 25 0.98 500 6 emulsion Detergent sewage

Washing and rinsing fluids, Industrial shampoos, Cleaning White Contact with SW-10 0.05 – 0.2 15 0.99 120 6 and degreasing baths, emulsion food Detergent sewage

Softening fluids based on SW-60 White quaternary ammonium salts 0.001 – 0.1 20 1.00 150 6 technical emulsion

Softening fluids based on White FC-13 0.05 – 0.2 10 1.00 100 6 technical quaternary ammonium salts emulsion

Information included in this document is presented in good faith, based on our current knowledge and experience. Product information only approximates its utility parameters and physical and chemical parameters which cannot constitute grounds for any claims. Detailed parameters and their admissible ranges are listed in Technical Requirements for the product. We reserve the right to modify this technical information subject to advancements in technology and improvements to the product by manufactur

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