Foaming vs. Degreasing Efficiency: How to Choose the Right Surfactant for Industrial Cleaning Agents
Choosing surfactants for industrial cleaning agents is not just about efficiency, but also about balancing foaming and degreasing. Which types of surfactants should you select for different applications, and how do they affect the final cleaning quality?
Photo: PuroClean of Fort Worth / Unsplash
In industrial cleaning agents, surfactants play a key role – they reduce surface tension, enable wetting of surfaces, and emulsify dirt. However, their selection is not straightforward: while some types excel in degreasing, others generate excessive foam, which can complicate application in washing lines or automated systems. The right choice depends on the specific application, type of dirt, and technological requirements. In this article, we will explore the main categories of surfactants, their advantages, limitations, and practical tips for optimizing formulations.
Basic principles of surfactant action in industrial cleaning agents
Surfactants are a key component of industrial cleaning agents, as they reduce the surface tension of liquids and enable effective removal of dirt. Their action lies in the ability to form micelles—clusters of molecules that surround and emulsify fats, oils, and other non-polar substances. This leads to their release from surfaces and subsequent rinsing away. In industrial applications, anionic, non-ionic, cationic, and amphoteric surfactants are most commonly used, with each type having specific properties and areas of application.
Anionic surfactants, such as alkyl sulfates or alkylbenzene sulfonates, excel in strong degreasing ability and high foaming, making them ideal for aggressive cleaning agents. In contrast, non-ionic surfactants, for example ethoxylated alcohols, generate less foam but are gentler on sensitive surfaces and effective even in hard water. The choice of the right type depends on the specific application, type of dirt, and desired level of foaming.
Foaming: An Advantage or Obstacle in Industrial Cleaning?
Foaming is often perceived as an indicator of cleaning agent effectiveness, but in industrial applications, it can be more of a disadvantage. High foam can make handling the cleaning solution difficult, slow down processes, and increase water consumption during rinsing. For example, in automated washing lines or when cleaning large surfaces, excessive foam can lead to technical issues such as clogged nozzles or reduced pump efficiency.
On the other hand, in some cases foam is desirable – for example, in manual cleaning or applications where visual control of surface coverage is needed. For these purposes, anionic surfactants are often combined with foaming additives. In industrial environments where speed and efficiency are the priority, low-foaming or non-foaming surfactants, such as modified alcohols or silicones, are preferred. These ensure degreasing efficiency without unwanted foaming.
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Degreasing Efficiency: How to Maximize It Without Compromises
The degreasing efficiency of surfactants depends on their ability to penetrate fatty layers and emulsify them in an aqueous environment. A key factor is the hydrophilic-lipophilic balance (HLB), which determines how well the surfactant binds to fats while remaining soluble in water. For industrial degreasers, surfactants with an HLB in the range of 10–15 are typically chosen, as they provide an optimal balance between degreasing and emulsion stability.
To enhance efficiency, different types of surfactants are often combined. For example, a mixture of anionic and nonionic surfactants can ensure strong degreasing even at lower concentrations, reducing costs and environmental impact. It is also important to consider the temperature and pH of the cleaning solution—some surfactants are more effective in acidic or alkaline environments, while others require higher temperatures to achieve maximum performance.
Practical tips for selecting surfactants based on specific applications
When selecting a surfactant for industrial cleaning agents, several key factors must be considered. For aggressive degreasing of metal surfaces or machine components, anionic surfactants combined with alkaline additives are recommended, as they enhance efficiency in removing heavy dirt. Conversely, for sensitive materials such as plastics or painted surfaces, nonionic surfactants are more suitable, as they minimize the risk of damage.
In applications with limited rinsing, such as closed systems, it is important to select surfactants with low residual concentration that are easily rinsed off. For environmentally friendly products, biodegradable surfactants that meet sustainability requirements while providing sufficient efficacy can be used. It is always advisable to conduct laboratory tests with specific contaminants and surfaces to verify the compatibility and performance of the selected surfactant.
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Effect of pH and Temperature on Surfactant Performance: When and Why to Optimize Conditions
The performance of surfactants in industrial cleaning agents is not constant—it strongly depends on the chemical environment and physical conditions of the application. One of the key factors is the pH of the solution. Anionic surfactants, frequently used for their high degreasing efficiency, achieve optimal performance in alkaline conditions (pH 9–12), where they better emulsify fats and oils. In contrast, nonionic surfactants are less sensitive to pH and function effectively even in neutral or mildly acidic environments, which is advantageous for sensitive surfaces or systems with limited stability in alkaline pH.
Temperature has a similarly significant impact. Increasing temperature generally improves the solubility of impurities and accelerates chemical reactions, but for some surfactants, it may lead to a decline in surface tension beyond the optimal point. For example, ethoxylated alcohols (nonionic surfactants) lose effectiveness at temperatures above 60 °C due to a reduction in their hydrophilic character. In the case of anionic surfactants based on alkyl sulfates, high temperatures can cause hydrolysis, reducing their stability. To achieve maximum efficiency, it is therefore necessary to match the surfactant type with operating conditions—for instance, combining low-foaming surfactants with higher temperature resistance for machine washing or selecting stable surfactants for applications in extreme pH.
Synergistic Effects: Why Combine Different Types of Surfactants
In practice, cleaning agents based on a single type of surfactant are rarely encountered. The reason is synergy—the mutual enhancement of properties between different surfactants, leading to better performance at lower concentrations. A typical example is the combination of anionic and nonionic surfactants. Anionic surfactants excel in degreasing and foam formation, while nonionic surfactants improve wetting and emulsion stability, particularly in hard water. The result is a cleaning agent with balanced properties: strong degreasing ability but without excessive foaming that would hinder rinsing.
Another advantage of combinations is the ability to selectively suppress undesirable properties. For example, cationic surfactants, which are effective against static electricity and have antimicrobial effects, are often combined with non-ionic surfactants to prevent their strong adsorption on surfaces and the subsequent reduction in efficacy. For industrial applications where speed and efficiency are key, blends with a high content of non-ionic surfactants supplemented with anionic surfactants to improve degreasing have proven effective. It is important to test the compatibility of surfactants in the specific system, as an incorrect combination can lead to precipitation or loss of efficacy.
Ecological and Safety Aspects of Surfactant Selection
When selecting surfactants for industrial cleaning agents, ecological and safety requirements, which are becoming increasingly stringent, cannot be overlooked. According to the REACH regulation, all chemical substances, including surfactants, must be registered and evaluated in terms of their impact on health and the environment. Surfactants with high biodegradability, such as linear alkylbenzene sulfonates (LAS) or alcohol ethoxylates (AE), are preferred for applications where there is a risk of release into wastewater. Conversely, perfluorinated surfactants, although highly effective, are being gradually replaced by alternatives due to their persistence and bioaccumulation.
The safety aspect includes not only human toxicity but also material compatibility. Some surfactants can cause corrosion of metals or degradation of plastics, which is critical, for example, in the food or automotive industries. For sensitive applications, surfactants with low irritancy and neutral pH, such as amphoteric surfactants (e.g., betaines) or special non-ionic surfactants with a short ethoxylate chain, are therefore chosen. It is also important to consider the labelling requirements under the CLP/GHS regulation, which determines what safety symbols and statements must be included on the packaging of cleaning agents containing certain surfactants.
Need help selecting surfactants?
Every application requires an individual approach. GCG Group provides detailed technical data sheets and safety data sheets (SDS) for each raw material, and our experts will be happy to advise you on selecting surfactants tailored to your needs—whether it's low-foaming systems, powerful degreasers, or eco-friendly alternatives. Contact us—or browse our catalog of over 1,300 products right away.
