What is the more appropriate addition ratio of alkyl glycoside in laundry detergent?

2025-11-18 15:43:12

As green laundry has become the mainstream of consumption, Alkyl Polyglycoside (APG) has gradually replaced traditional petroleum-based surfactants and become one of the core components in laundry detergent formulations, thanks to its excellent surface activity, biodegradability and mildness. However, many manufacturers face a key issue in its application: what is the more appropriate addition ratio of alkyl polyglycoside in laundry detergent? There is no uniform answer to this question, as it requires comprehensive consideration of multiple factors such as the functional positioning of the laundry detergent, formulation system, application scenarios and cost control. This article will analyze the influencing factors of APG addition ratio from both scientific principles and practical application perspectives, provide suitable ratio ranges for different scenarios, and discuss the core logic of ratio optimization.

As a non-ionic surfactant, the core function of APG is to separate oil stains from clothing fibers by reducing the surface tension of water, while also having multiple functions such as emulsification, dispersion and solubilization. In laundry detergent formulations, its addition ratio directly determines the key properties of the product, such as detergency, mildness and stability. When the ratio is too low, the surface activity is insufficient to effectively break down oil stains, especially for stubborn stains such as chili oil and cooking oil, resulting in significantly reduced detergency. On the other hand, an excessively high ratio not only increases production costs, but may also lead to excessive foam in the laundry detergent that is difficult to rinse off. Residues on clothing surfaces can cause skin irritation, and may also affect the stability of the formulation system, leading to problems such as stratification and precipitation. Therefore, finding the "optimal ratio range" is a core link in balancing product performance and cost.

The primary factor affecting the addition ratio of APG is the functional positioning of the laundry detergent. Laundry detergents with different functions have significantly different requirements for APG. For general-purpose basic laundry detergents, the core requirement is to meet the cleaning needs of daily light stains while controlling costs, targeting a broad consumer market. In such products, the addition ratio of APG is usually 5%-8%. Within this range, APG can form a synergistic effect with other auxiliary Surfactants (such as sodium dodecylbenzene sulfonate and sodium alcohol ether sulfate), which not only ensures basic detergency, but also reduces the irritation of traditional surfactants by virtue of its mildness, while controlling raw material costs within a reasonable range. Taking a well-known brand of general-purpose laundry detergent as an example, its formula contains 6.5% APG and 3% sodium dodecylbenzene sulfonate. According to third-party testing, its detergency rate for daily dirt and sweat stains is over 92%, and its skin irritation test reaches the "non-irritating" level.

For mid-to-high-end concentrated laundry detergents, since the products emphasize the characteristics of "high-efficiency detergency, low foam and easy rinsing, mildness and clothing protection", and the concentrated formula means a higher content of active ingredients per unit volume, the addition ratio of APG needs to be increased to 8%-12% accordingly. Concentrated laundry detergents are usually targeted at consumer groups with higher requirements for washing quality, such as maternal and infant families and people with sensitive skin, who pay more attention to the mildness and detergency efficiency of products. The high proportion of APG can, on the one hand, reduce the reliance on irritating surfactants, and on the other hand, its excellent emulsifying and dispersing ability can form a stronger cleaning effect on stubborn stains such as hot pot oil and soy sauce. In the formula of a concentrated laundry detergent specially designed for infants and young children, APG accounts for 10%, without adding traditional anionic surfactants, only matching 2% cocamidopropyl betaine as an auxiliary component. Its detergency rate for common stains on baby clothes, such as milk stains and saliva stains, reaches 98%, and it is suitable for the sensitive skin of infants and young children through skin patch testing. At the same time, the low-foam characteristic brought by the high proportion of APG also conforms to the selling points of concentrated laundry detergents such as "easy to rinse, water and electricity saving", avoiding the problem of foam residue.

For special functional laundry detergents, such as those for wool and silk, and bactericidal laundry detergents, the addition ratio of APG needs to be flexibly adjusted according to specific functional requirements. Wool, silk and other protein fiber clothes have soft textures that are easily damaged, requiring extremely high mildness of detergents, and also need to avoid clothing shrinkage and fading. In such laundry detergents, the addition ratio of APG is usually 4%-6%. Although the ratio is relatively low, a large amount of mild amphoteric surfactants (such as cocamidopropyl hydroxysultaine) need to be matched to ensure detergency while maximizing the protection of clothing fibers. In a wool-specific laundry detergent, APG accounts for 5%, matched with 4% amphoteric surfactants. Tests show that the tensile strength retention rate of wool clothes after washing is over 95%, without shrinkage or deformation. In bactericidal laundry detergents, since they need to be compatible with bactericidal ingredients (such as quaternary ammonium salts and plant extracts), the ratio of APG is usually controlled at 7%-9%, which neither affects the stability of bactericidal ingredients due to excessively high ratio nor leads to insufficient detergency due to excessively low ratio. Studies have shown that when the proportion of APG is 8%, it has the best compatibility with quaternary ammonium salt bactericidal ingredients, the bactericidal rate can reach 99.9%, and the detergency is not affected.

In addition to functional positioning, the composition of the laundry detergent formulation system also has an important impact on the addition ratio of APG. The compounding effect of surfactants is one of the key factors determining the ratio. When APG is compounded with different types of surfactants, the strength of the synergistic effect varies, and the required ratio also changes accordingly. When compounded with anionic surfactants, the two can form micelle structures to enhance detergency, and the proportion of APG can be appropriately reduced at this time. When compounded with non-ionic surfactants (such as fatty alcohol polyoxyethylene ether), the main purpose is to improve the mildness of the product, and the ratio can be adjusted according to the mildness requirements. When compounded with amphoteric surfactants, the foam performance and stability can be optimized, and the ratio needs to be set according to the foam requirements. For example, when APG and sodium alcohol ether sulfate (AES) are compounded at a ratio of 1:1, with the total surfactant content being 10%, 5% APG can achieve the detergency effect of 8% APG used alone, which is the ratio optimization space brought by the synergistic effect.

The builder components in the formula will also affect the actual efficacy of APG. Chelating agents such as sodium tripolyphosphate and 4A zeolite can remove calcium and magnesium ions in water, avoiding the inhibition of surfactants by hard water. At this time, the proportion of APG can be appropriately reduced by 1%-2%. The addition of enzyme preparations (such as protease and lipase) can specifically decompose protein and fat stains, forming a functional complement with APG, which can also reduce the reliance on APG. In the formula of a laundry detergent containing enzymes, due to the addition of 0.5% lipase, the proportion of APG is reduced from the conventional 7% to 5.5%, but the detergency rate for oil stains is increased by 5%, which not only ensures performance but also reduces costs. In addition, although auxiliary materials such as thickeners, preservatives and fragrances do not directly participate in detergency, excessive addition may affect the compatibility of the system, indirectly leading to the need to increase the proportion of APG to ensure efficacy. Therefore, the overall balance of the formula is crucial.

Differences in application scenarios and consumer demands are also important bases for adjusting the proportion of APG. From a regional perspective, the water quality in northern China is relatively hard, with high content of calcium and magnesium ions, which will combine with surfactants to form insoluble precipitates and reduce their activity. Therefore, the proportion of APG in laundry detergents for the northern market needs to be 1%-2% higher than that for the southern market, usually 6%-9%, while in the southern soft water areas, the proportion can be controlled at 5%-7%. From the perspective of usage methods, laundry detergents for machine washing need to consider foam volume and rinsing performance, and the proportion of APG is generally 5%-8% to avoid excessive foam clogging the washing machine. Hand-washing laundry detergents emphasize the balance between mildness and detergency, and the proportion can be increased to 7%-10% to reduce irritation to hand skin. From the perspective of consumer groups, laundry detergents for people with sensitive skin need a higher proportion of APG, usually 8%-11%, to reduce the use of other irritating ingredients. For economical laundry detergents targeting the rural market, the proportion can be controlled at 4%-6%, and the selling price can be reduced by matching low-cost auxiliary components.

In the process of determining the addition ratio of APG, enterprises also need to establish a scientific testing system and verify the optimal ratio through multi-dimensional tests. Basic tests include detergency testing, which refers to GB/T 13174-2021 "Washing Powder" standard, using standard soiled cloth to test the detergency value (RB value) under different ratios. When the RB value reaches above 1.0, the detergency effect meets daily needs. Stability testing requires storing the laundry detergent at -5℃ and 45℃ for 48 hours, observing whether the laundry detergent has stratification, precipitation, discoloration and other phenomena to ensure the system is stable at different temperatures. Mildness testing evaluates the safety of the product to the human body through skin irritation tests and eye irritation tests. Foam performance testing needs to control the foam height within a reasonable range. The foam height of machine-washing products is usually required to be below 100mm, while that of hand-washing products can be appropriately relaxed to 150mm. Through these tests, the optimal ratio range of APG under different formulas can be accurately positioned, avoiding product performance problems caused by empirical judgment alone.

With the development of green chemical technology, the production cost of APG has gradually decreased, and its application ratio in laundry detergents has also shown a steady upward trend. In the future, with the further upgrading of consumers' demand for environmentally friendly and mild products, and the continuous optimization of formula technology, the addition ratio of APG may develop in the direction of "high efficiency and low consumption" - through the innovation of compounding technology, the performance can be improved while reducing the total addition amount, achieving "defeating more with less". For example, the combination of nanotechnology and surfactants can enhance the dispersibility of APG, enabling it to achieve excellent detergency even at a low ratio of 3%-5%, which not only reduces costs but also further improves the environmental performance of the product.

To sum up, there is no fixed standard for the addition ratio of APG in laundry detergents. The core is "adapting to needs" - flexibly adjusting within the conventional range of 5%-12% according to product functional positioning, formulation system, application scenarios and consumer demands, and verifying the rationality of the ratio through scientific tests. In actual production, enterprises need to establish a three-dimensional evaluation system of "performance-cost-experience", which not only ensures that APG fully exerts its advantages of environmental protection, mildness and high efficiency, but also optimizes the cost-effectiveness of the product, so as to gain an advantage in the fierce market competition. For consumers, understanding the addition logic of APG can also help them more accurately select suitable laundry detergent products according to their own needs, realizing scientific laundry.