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A Comprehensive Guide to Liquid Detergent Viscosity: Understanding the Importance, Factors, and Applications

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Liquid detergents play a crucial role in our daily lives, with a wide range of types and formulations available. Viscosity, or referred to as thickness, is an essential factor in determining the effectiveness of these detergents, influencing their flowability, stability, and cleaning performance. For industry insiders such as liquid detergent business owners, formulators, production operators, raw material suppliers/distributors, and those interested in joining this business chain, understanding viscosity is key to developing and selecting high-performing products.

A. The role of viscosity in liquid detergents

Viscosity refers to a liquid’s resistance to flow. In the context of liquid detergents, viscosity impacts several factors, including the product’s flowability, stability, and cleaning performance. It is essential for consumers and manufacturers to have a basic understanding of these properties when selecting or formulating detergent products.

B. Types of liquid detergents

Liquid detergents are available in various forms, including laundry detergent, dishwashing liquid, hand soap, floor cleaner, toilet bowl cleaner, multi-functional cleaners, etc. Each type has unique characteristics that are optimized for specific cleaning tasks, but all rely on effective viscosity management to ensure optimal performance and consumer preferences.

Essentials of liquid detergent viscosity

Certain viscosity values are favored for various types of liquid detergents due to different usage scenarios and consumer preferences. Viscosity can also impact a detergent’s cleaning performance, making it essential for industry insiders to understand this concept when selecting or formulating cleaning products.

A. Ideal viscosity values for various liquid detergents

The ideal viscosity values for various types of liquid detergents may differ depending on factors such as market, location, or the country it is being sold in. For instance, laundry detergents typically have higher viscosity than dishwashing liquids, ensuring that they remain stable while traveling through washing machine tubing. Dishwashing liquids, on the other hand, may require lower viscosity values to optimize their flow and effectiveness during the dishwashing process. However, consumer preferences can vary significantly across different regions. In China, liquid laundry detergents are commonly sold with a viscosity range of 500-1200 centipoises(CP), while in some African countries, such as Ethiopia, consumers prefer very thick liquid detergent products with viscosities around 3000 centipoises(CP).

Thus, when formulating a new liquid detergent product, there are no existing gold standards to follow. Instead, it’s essential to analyze well-accepted products already in the market and conduct further consumer surveys to understand the most accurate consumer preferences. This approach will ensure the development of a product that caters to the specific needs and expectations of your target market, enabling your product to be successful and widely appreciated.

Pouring detergent into a washer

B. Measuring viscosity at room temperature (24°C)

The viscosity of liquid detergents is typically measured at room temperature (24°C) to provide a baseline for assessing their effectiveness in various conditions. Viscosity can change with temperature, so it is essential to obtain accurate and comparable measurements. Additionally, multiple methods and instruments can be employed to measure the viscosity of liquid detergents.

  1. Viscometers – These devices are designed to measure the viscosity of fluids. Common types include:
    • Rotational viscometers: These instruments consist of a spindle immersed in the liquid detergent sample. As the spindle rotates at a controlled speed, the resulting drag force is measured to determine the sample’s viscosity. This is the most commonly used viscometer type in the detergent industry.
    • Capillary viscometers: These devices use a narrow tube (capillary) to measure the time it takes for a liquid detergent sample to flow through the tube under gravity. The flow rate can then be used to calculate the sample’s viscosity.
  2. Rheometers – Rheometers are more sophisticated instruments capable of characterizing a fluid’s rheological properties beyond just viscosity. These devices provide more in-depth information about the flow behavior and viscoelastic properties of a liquid detergent sample under various conditions, such as changes in temperature, pressure, or shear rates.
Testing the viscosity of a detergent sample using a Rotational viscometer

When measuring the viscosity of liquid detergent samples, it is crucial to ensure that the sample is properly prepared and the measurement conditions are well controlled. This might entail using a consistent sample size, testing at a constant temperature, and following the recommended procedures provided with the selected measurement instrument. By obtaining accurate viscosity measurements, manufacturers can better understand the quality and performance of their detergent products, enabling them to fine-tune formulations and improve product performance.

C. Connections between viscosity and cleaning performance

Viscosity plays a crucial role in a detergent’s cleaning performance. An ideal detergent should have a suitable viscosity to efficiently deliver its cleaning agents. If the viscosity is too high, it can hinder the product’s flowability, while a detergent with too low viscosity may not maintain its stability or effectively remove dirt and stains.

Although many consumers often relate higher viscosity to better cleaning performance, this may not always be the case. There are numerous factors that can influence the viscosity of a detergent product, such as the usage of a thickening agent, temperature, the presence of bubbles, and more. Moreover, the optimal viscosity for each cleaning product might differ depending on the intended application and usage conditions.

Pouring dishwashing liquid onto a washing sponge

Factors affecting liquid detergent viscosity

Various factors can impact a detergent’s viscosity, including its formulation components, temperature, pH level, and the presence of bubbles.

A. Formulation components

  1. Surfactants: Surfactants are one of the primary ingredients in detergents. They can significantly impact viscosity because they help reduce surface tension and promote the formation of micelles (tiny particles composed of surfactant molecules). As a result, different types and concentrations of surfactants can lead to various viscosity values. Certain surfactants like Cocamide DEA(CDEA) and Cacamidopropyl Betaine(CAPB) have pronounced thickening effects. They are commonly added into detergent formulations as secondary surfactants for viscosity building.
  2. Solvents: Solvents, which are typically water or organic compounds like alcohols(commonly Ethanol or Propylene glycol) in the context of detergent formulations, are primarily used to dissolve or dilute other ingredients. They typically reduce the viscosity of the solution because they interrupt the interactions between other molecules or particles that contribute to a higher viscosity.
  3. Additives: Additives such as thickeners, fragrances, and colorants can also influence a detergent’s viscosity. These components may interact with the surfactants and solvents in various ways, either increasing or decreasing viscosity.

B. Temperature

Temperature can significantly impact a detergent’s viscosity. As the temperature increases, viscosity generally decreases due to the faster movement of molecules within the liquid. However, some detergent components may exhibit a more complex behavior, and it is crucial to consider how temperature changes can impact viscosity, especially during manufacturing, storage, and application.

C. Presence of bubbles

Bubbles can also influence a detergent’s viscosity. Bubbles may form during the production process or use, causing an increase in apparent viscosity. Proper formulation and manufacturing techniques can help minimize the presence of bubbles and ensure a consistent, accurate viscosity reading.

D. pH level

The pH level of a detergent can affect its viscosity as some thickeners are pH-dependent and may cause the detergent to thicken or thin within specific pH ranges. Optimizing pH in the formulation process ensures the detergent achieves the desired viscosity without compromising its cleaning performance or stability.

Benefits of controlling viscosity in liquid detergents

By managing detergent viscosity, manufacturers and consumers can reap several benefits:

A. Improved use experience

A detergent with the appropriate viscosity can move smoothly through the application process, ensuring even distribution and easier cleanup. For example, a liquid laundry detergent with too low viscosity can flow too easily out of the bottle, which makes it hard to control the dosage. In contrast, a liquid hand soap with excessive thickness will be difficult to apply and disperse on the palm and fingers for thorough cleaning.

B. Enhanced penetration and cleaning performance

A detergent with the optimal viscosity will effectively dissolve and remove dirt, grease, and stains. Detergents with the wrong viscosity may struggle to clean surfaces and leave residues behind.

C. Stability during storage and use

Proper viscosity control ensures the detergent remains stable and consistent, preventing separation or other issues that can affect its performance.

D. Consumer anticipation and preferences

Due to various factors, consumers may have certain expectations about a detergent’s viscosity. Logically or not, this perception has an effect on their product choice. Generally, a detergent with a thin body may give the impression of lower cleaning performance, whereas higher viscosity may be associated with better cleaning abilities. By controlling the viscosity and meeting these expectations, manufacturers can cater to consumer preferences and enhance the overall user experience.

Pumping handsoap liquid onto palm

Delving Deeper: The Role of Surfactants in Shaping Detergent Viscosity

Surfactants stand as an indispensable component of detergent formulas, wielding substantial influence over the product’s viscosity and, consequently, its efficiency in cleaning.

A. The Surfactant-Viscosity Interplay

Surfactants function by reducing surface tension and encouraging the creation of micelles – small clusters of surfactant molecules. This process is instrumental in establishing a detergent’s viscosity. The type of surfactant incorporated, coupled with its relative concentration, can meaningfully alter the viscosity profile of the detergent.

B. The Viscosity Effect of Various Surfactant Types

Detergent formulations feature a myriad of surfactants, including anionic, nonionic, cationic, and amphoteric variants. Each category possesses distinct characteristics and exerts a unique influence on viscosity. An understanding of these properties is crucial for manufacturers as they strive to balance the right viscosity with effective cleaning performance.

C. The Synergistic Effect of Surfactants

Notably, surfactants can work together to optimize viscosity, thanks to their synergistic effects. The right combination of surfactants can significantly enhance the viscosity of the detergent formula beyond the sum of their individual effects. This synergy allows for even greater control over the product’s final viscosity and performance. It’s very common to use an anionic surfactant such as Sodium Laureth Sulfate(SLES) and a nonionic surfactant such, commonly Cocamide DEA(CDEA), and/ or an amphoteric surfactant, commonly Cocamidopropyl betaine(CAPB) or Cocamidopropylamine oxide(CAO) to achieve synergistic effect for the best viscosity and overall performance.

Techniques for increasing liquid detergent viscosity

There are several methods to increase the viscosity of liquid detergents:

A. Adjusting surfactant concentration and type

Modifying the surfactant blend or concentration can influence detergent viscosity. Adding more surfactant or adjusting the proportion of different surfactant types can change the detergent’s micellar structure, leading to an increase in viscosity.

B. Modifying solvents and additives

The choice of solvents and additives can also affect detergent viscosity. By selecting components with higher viscosity values or altering their concentrations, manufacturers can increase the overall detergent viscosity.

C. Employing thickening agents

Thickening agents, such as NaCMC or HPMC, can be added to detergent formulations to increase viscosity. These agents work by forming a network structure within the liquid detergent, providing the necessary resistance to flow while maintaining cleaning performance.

Viscosity comparisons: Common liquid detergents vs. other liquids

The viscosity of liquid detergents varies considerably based on the formulation, type, and application. Common liquid detergents’ viscosity values can range from a few centipoises (similar to water) to several thousands of centipoises. This broad range allows manufacturers to tailor the detergent’s properties to specific applications and consumer preferences.

For comparison, the viscosity of water at room temperature is approximately 1 centipoise, while other household fluids (such as butter fat or deodorized butter) can have viscosity values in the tens or hundreds of centipoises.

Innovative developments in liquid detergent viscosity

Advancements in detergent technology have led to new formulations and methods for controlling viscosity. Some recent developments include:

A. Highly viscous detergent emulsions

Highly viscous detergent emulsions are a promising area of innovation. These products offer enhanced cleaning performance and easier application due to their unique, gel-like consistency. Highly viscous emulsions are particularly effective in laundry, ware washing, clean-in-place, and dairy applications.

B. New methods for controlling viscosity

Advancements in material sciences and manufacturing processes have led to new methods for controlling detergent viscosity. These techniques include the development of novel thickening agents, innovative formulation strategies, and adoption of advanced manufacturing technologies.

C. Potential applications and benefits

Innovative developments in detergent viscosity control can lead to improved cleaning performance, more eco-friendly formulations, and better user experiences. These advancements can benefit both consumers and manufacturers by providing products tailored to various cleaning tasks and preferences.

Challenges and Considerations in liquid detergent viscosity control

Despite the advancements in detergent technology, there are still challenges and considerations when managing detergent viscosity.

A. Formulation complexities

Balancing various properties, such as cleaning performance, viscosity, and stability, can be challenging due to the complex interactions between ingredients. Manufacturers must consider trade-offs when selecting surfactants, solvents, and additives to develop formulations with desirable characteristics.

B. Balancing performance and cost

Formulation optimization often involves balancing performance and cost. High-quality ingredients and innovative manufacturing processes may provide better viscosity control but can also increase production costs. Manufacturers must carefully assess these factors during formulation development.

C. Regulatory and environmental factors

Government regulations and consumer demand for eco-friendly products can also impact the formulation process. Manufacturers must consider how the choice of ingredients, production processes, and packaging can affect the product’s environmental footprint and regulatory compliance.

Case studies: Investigating viscosity in liquid detergent manufacturing

Analyzing viscosity in practical applications, such as during manufacturing and production processes, can reveal the importance of viscosity control and the key factors that influence detergent performance.

A. Viscosity analysis of random detergent batches

Random samples of detergent batches can provide valuable insights into the consistency and performance of various formulations. Comparing viscosity values across multiple batches helps manufacturers identify any variability in their processes and make necessary adjustments.

B. The role of quality control in ensuring optimal viscosity

Manufacturers rely on quality control measures to ensure that their products meet performance, safety, and regulatory standards. Proper quality control procedures can catch issues, such as inconsistencies in viscosity or other properties before the detergent reaches consumers.

Examining popular detergent brands can reveal how manufacturers prioritize viscosity and detergent performance, as well as any unique approaches to viscosity management.

A. Brand analysis and key takeaways

Analyzing viscosity values and formulation strategies of popular brands can provide insights into what consumers prefer and how manufacturers balance various properties, such as cleaning performance, stability, and flowability.

B. Consumers’ perception of viscosity in liquid detergents

Understanding consumers’ perceptions of viscosity is essential for developing liquid detergents that cater to their preferences and expectations. Consumer preferences regarding viscosity can be influenced by multiple factors, including ease of use, efficiency, and cultural differences.

A. Ease of use

Viscosity can significantly impact a detergent’s ease of use. For instance, users may prefer low-viscosity detergents for applications where quick penetration and easy rinsing are required, such as dishwashing or hand soaps. On the other hand, a higher viscosity may be desired for applications where the detergent needs to cling to surfaces, like in bathroom cleaners or laundry detergents.

B. Efficiency and performance

Consumer perception of a detergent’s effectiveness often influences their preferences for viscosity. It is crucial to strike a balance between the desired viscosity and the cleaning power of the detergent to meet various user expectations. If an increase in viscosity negatively impacts the detergent’s cleaning ability, consumers may prefer a lower viscosity product that performs more effectively.

C. Cultural differences

Cultural differences can also play a role in consumer preferences for detergent viscosity. Tradition, lifestyle habits, and regional expectations regarding detergent consistency may influence consumer choices. For example, people in some regions may prefer thicker detergents, associating a higher viscosity with a stronger cleaning ability, while others might appreciate thinner, more easily rinsed detergents.


Liquid detergent viscosity is a key factor in the overall performance and consumer appeal of detergent products. By understanding and controlling detergent viscosity, manufacturers can develop products that cater to consumer preferences while maintaining cleaning effectiveness.

Innovations in formulation strategies, thickening agents, and production processes have led to a wide range of detergent viscosities available to consumers. Viscosity management remains a challenging process, but advancing technologies and a deeper understanding of consumer preferences have the potential to shape the future of the detergent industry.

Frequently Asked Questions about Liquid Detergent Viscosity

Q1. What increases the viscosity of liquid detergent?

There are several methods to increase the viscosity of liquid detergents:

  • Adjusting surfactant concentration and type
  • Modifying solvents and additives
  • Employing thickening agents, such as NaCMC or HPMC

Q2. Does detergent increase viscosity?

Detergents can increase the viscosity of a solution when added to it, mainly due to the presence of surfactants and thickening agents.

Q3. Why is viscosity important to detergents?

Viscosity is important to detergents because it:

  • Affects the ease of use and application
  • Influences the detergents’ cling to surfaces, which is crucial for specific cleaning tasks
  • Impacts the overall perception of detergent quality and performance

Q4. What are the qualities of liquid detergent?

Some qualities of liquid detergent include:

  • Effective cleaning performance
  • Ease of use and rinsing
  • Long shelf-life and stability
  • Compatibility with different surfaces and materials
  • Pleasant fragrance and appearance

Q5. What makes liquid detergent thick?

Liquid detergent can be made thick by incorporating thickening agents, such as NaCMC or HPMC. Adjusting surfactant concentration and using specific additives can also contribute to increased viscosity.

Q6. How do you increase the thickness of liquid detergent?

To increase the thickness of liquid detergent, you can:

  • Increase the surfactant concentration or adjust the proportion of different surfactant types
  • Use high-viscosity solvents or additives
  • Add thickening agents, like NaCMC or HPMC
Written by:
Jun Xie
Jun Xie
Jun is the head of R&D at Yeser Chemicals. He holds a master's degree in Chemical Engineering and Technology. After joining Yeser Chemicals in 2013, he has been dedicated to researching and developing new coconut-based green surfactants and their safe uses in Home & Personal care products. In addition to serving as the Head of R&D at Yeser Chemicals, Jun is the director of the Guangdong Green Surfactant Engineering Technology Research Center and a member of the Standard Committee of Guangdong Daily Chemical Chamber of Commerce.

Yeser Chemicals is a leading producer of CAPB, CDEA, CMEA, EGDS, and other various Coconut-derived surfactants.

By self-manufacturing and 3rd-party toll-manufacturing, we provide a long list of safe ingredients, including surfactants, conditioners, thickeners, etc.,  used in Home & Fabric Care, Personal Care, and Cosmetics.

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