The consistency of a liquid detergent is primarily determined by its ingredients and how it is processed. Here are the key factors that make liquid detergent thicker:

1. The role of thickener
Thickeners are the primary consistency-adjusting ingredients in detergent formulations. Commonly used thickeners include:
Water-soluble polymers: such as hydroxyethyl cellulose (HEC), sodium polyacrylate, etc. These substances can absorb water and swell to form a colloidal solution with a certain viscosity.
Inorganic thickeners: such as silicates, calcium carbonate, etc., can increase the viscosity by increasing the density and volume of the dispersed phase.
Salts (such as sodium chloride, sodium sulfate): Adding in appropriate amounts can enhance the interaction between surfactant molecules, thereby increasing the consistency of the liquid.

2. Type and concentration of surfactants
Surfactants are the core ingredients of liquid detergents, and their type and concentration can significantly affect consistency:
Structure of surfactants: Surfactants with longer molecular structures or larger hydrophilic/hydrophobic balances are more likely to form sticky systems.
Micelle Concentration: When a surfactant reaches a critical micelle concentration, micelles form and these micelles can significantly increase the viscosity of the liquid through interaction.

3. pH value of solution
Liquid detergents usually need to be maintained within a specific pH range (such as neutral or slightly alkaline) to ensure their stability and performance. In some cases, changes in pH can alter the solubility of certain ingredients, thereby affecting the consistency of the liquid. For example:
In alkaline environments, some anionic surfactants may form gel-like structures.
Adjustment of the pH value can optimize the effect of the thickener.

4. Other ingredients in the formula
Solvents: Water is the primary solvent, but certain cosolvents (e.g., propylene glycol, ethanol) can affect viscosity. They can reduce the free flow of the system and make the liquid thicker.
Additives: Such as fatty alcohols or fatty acids, often used to improve the consistency and feel of detergents.
Emulsifiers and Stabilizers: Help maintain an even distribution of ingredients in a liquid and prevent stratification, thereby increasing the overall consistency.

5. Physical processing conditions
During the production process, the control of physical conditions also has a certain impact on liquid consistency:
Shear force and mixing speed: Moderate mixing can promote the uniform distribution of ingredients and the formation of micelles, increasing viscosity.
Temperature Control: Heating or cooling changes the rheological properties of a liquid, thus affecting the consistency.

6. Consumer demand and formulation design
Different markets and consumers have different preferences for detergent consistency. To meet these needs, manufacturers adjust formulations and processing techniques to make liquid detergents both ideal for use and easy to package and store.

The consistency of liquid detergents is achieved through scientific formulas and precise processing. By selecting appropriate thickeners, surfactants and other formulation ingredients, and optimizing production conditions, the consistency of liquid detergents can be controlled to meet different application needs.