Powder Detergent: Ingredients and Manufacturing Process Explained

From ancient times, people were manufacturing some kind of soaps. Even today, the difference between soap and detergent powder is strict - but not huge.

Traditional methods commonly included boiling fats and ashes. Modern production, although greatly improved, relies on the same essential properties.

While the powder detergent is dry and enhanced with a range of technologically advanced additives - it’s still technically based on fatty acids and lye.

In this article you can read about:

What is detergent powder?

What is the meaning of “detergent powder?”

By definition, it’s a soap in the form of a powder that is used to wash clothes, sheets, towels, and fabrics in general. It can be used in a washing machine or for manual washing.

Powder detergent is one of the more traditional washing solutions, with two key advantages: affordability and power against heavy stains.

These advantages, among others, lead to the resurgent popularity of detergent powder worldwide, while its affordability makes it a particularly convenient market product for countries in development.

Is detergent powder the same as washing powder?

Powder detergent is a broad term encompassing all kinds of soap manufactured in powder form.

However, it’s commonly used as a synonym for laundry detergent. While most formulas are suitable for both machine and hand washing, some products are targeted for specific use.

What is powder detergent used for?

Powder detergent is used for removing stains, typically from various kinds of fabric. It’s a popular and affordable option for cleaning fabrics, available in recyclable, eco-friendly packages such as cardboard boxes.

Powder detergent pros

  • Affordability
  • Recyclable packages
  • Excellent for removal of heavy stains 
  • Brightening and whitening properties
  • Specific optional ingredients such as oxygen bleach

Powder detergent cons

  • Dosing can be tricky and messy
  • Lower quality formulas can leave residue or dissolve only partially on low temperatures
  • The package is sensitive to water and tear
  • Not the best solution for pre-treatment of stains
Key takeaway

The detergent powder is a traditional compound for washing fabrics, an upgraded version of plain soap. It’s powerful against heavy stains, often packed in eco-friendly boxes, and more affordable than other laundry washing solutions.

How do you make detergent powder?

There are three common ways to create the initial mass. 

One is the blender or dry mixing process. The ingredients mix inside the blender machine, slowly running out onto a conveyor belt which takes them to the next step, or to the packaging.

Another way is the agglomeration process, similar to what happens inside a food processor. Sharp blades shred the mass to create a fine powder, which then gets sprayed with the liquid ingredients.

The heat produces viscous, gel-like liquid, easy to crush when dried. The detergent created by this method is recognizable by its distinctive, granule-like appearance.

The slurry method contains ingredients dissolved in water. A pump blows the slurry inside a spray drying tower where the hot, dry air causes it to dehydrate, creating beads of dry detergent.

This is the most reliable process of the three, thus strongly recommended. In this article, we will also break the key elements of manufacturing in a detergent powder production plant.

If you want to skip to that section please click this link.

PLC room for powder detergent production in STPP Group's factory
PLC room for powder detergent production in STPP Group’s factory

How do you make high-quality washing powder?

The best powder detergents are lightweight puffed powders with excellent free-flowing properties. Their average bulk density ranges between 250-500 g/l, comprising hollow particles with dimensions of 0.2-2.5mm. The spray drying tower is the most dependable way to obtain a mass with such properties.

What is the pH of detergent powder?

The “pH”  is an abbreviation of “potential of hydrogen” used for measuring the detergent formula’s acidity or alkalinity. Acid and basic make two extreme ends of the pH scale.

Balancing and perfecting the pH level of detergent powder is obtained through pH modifiers.

Most liquid cleansers, dishwashing liquids, beauty bar soaps, and similar products fall into the slightly acidic to neutral pH category.

It’s necessary for products that need to be compatible with the pH levels of human skin. Powdered laundry detergents, on the other hand, belong to the same spectrum as bar soaps with a pH in the alkali range.

How do you test the pH of detergent powder?

When chemical ingredients are dispersed in water, the mixture’s pH level defines whether it’s an acidic, alkaline, or neutral compound.

Key takeaway

There are three major, contemporary manufacturing methods of detergent powder. The STPP group production is focused on the slurry method. The spray drying tower process ensures the highest quality product with excellent free-flowing properties.

Powder detergent spray drying process explained

Modern powder detergents comprise a lightweight, free-flowing, puffed mass. In those terms, compared to dry mixing and agglomeration processes, spray drying delivers a superior product.

The mass created this way is lightweight, almost perfectly dehydrated, with minimal risk of issues such as caking of the final product.

Illustration of the process flow of powder detergent manufacturing by STPP Group
Illustration of the powder detergent manufacturing process in STPP Group’s factories

1. Handling raw materials

Before anything, it’s necessary to handle raw materials properly, and that includes storage and transport. There are two types of chemical ingredients used in the production of powder detergent: liquid and solid.

Most solid ones come in powdered form, packed in woven bags, such as Soda Ash or STPP, while liquids like LABSA or Caustic lye are commonly stored in tanks.

2. Raw materials dosing

After the ingredients have been loaded in appropriate tankers, the automated process starts with measuring and dosing. To ensure smooth and precise flow, every step is monitored and controlled by an operator-surveyed PLC system.

All formulas and details are stored in the system memory and applied automatically. An average manufacturer works with hundreds of formulas, from their own branded products to specialized contract manufacturing recipes.

3. Preparation and aging of slurry 

After the ingredients have been dosed and delivered by pipes and conveyors, they are mixed to form a base powder. First, the Crutcher stirs and mixes them with processed water for up to one hour, on average.

The mixed slurry then goes to “age” for up to half an hour in the aging tank.

4. Spray drying phase

After aging, the pumps start to spray the mix up to the top of the spray drying tower. The nozzles in the tower form atomized droplets, while the hot air furnace produces hot air to dehydrate them further.

In the end, the spray-dried granules (particles) fall to the bottom of the tower where they are collected and stored as a base powder.

The base powder is a semi-finished product that contains no enzymes, fragrances, or colorful speckles. It can be further customized per need, delivered for private labeling, or sold as bulk washing powder.

5. Filtration process

After all moisture has been evaporated, the hot air cools down and needs to be discharged. The reason is that the exhausted air contains fine dust residue.

Also, the base powder needs filtering by a mesh – such as a vibrating screen – to eliminate all oversized particles and scrapes.

6. Post-tower dosing and blending

The post-tower processing plant performs the fine-tuning of the base powder.

Additives such as enzymes, fragrances, colorful speckles, and all ingredients that cannot pass through the spray drying process are added and blended with the original mixture to form a customized product.

The finished powder then travels to the storage bins and packing machines for final packing.

7. Packing & Labeling

In the final step, manual and automatic packing machines load the pouches, buckets, and woven bags with washing powder detergent.

Key takeaway

There are three ways to produce powder detergent: blender, agglomeration, and slurry method. The last one, performed in a spray drying tower, is the most reliable one. It comprises seven essential steps, from dosing and mixing raw ingredients to post-processing and packaging of the product.

What are the ingredients of detergent powder?

The detergent powder is a synthetic compound that can be closely described as an upgraded soap. Its functional power is improved to bypass some standard issues that come with soaps. 

An average washing powder contains between 9 and 17 ingredients, both solid and liquid ones.

All Detergent chemicals from STPP Group
Display of various chemical ingredients required for detergent manufacturing by STPP Group

What is the chemical composition/formula of detergent powder?

A common soap is based on fatty acids and made functional by a combination of different molecules. While a hydrophilic soap molecule is attracted to water, the hydrophobic end of the molecule is drawn to the fat in the dirt.

The problem occurs in hard water – its minerals react with soap to form an insoluble curd. Known as precipitate, it leaves visible deposits on fabrics, making it stiff and unappealing. 

Hydrocarbons used in soap typically have a plant or animal origin, while those used in powder detergent can be acquired from crude oil.

Combining them with sulfuric acid results in a molecule similar to the fatty acids in soap. Adding alkali to the mix produces a surfactant molecule.

Detergent powder ingredients explained

Modern powder detergent formulas comprise several different types of ingredients. Each ingredient has its specific role, while many support each other to make the most out of the formula’s properties.


Builders are the ultimate component of any detergent base powder. They enhance the efficiency of the surfactant, while also affecting minerals in hard water to prevent precipitation.

Apart from that, builders can emulsify fat, turning it into washable tiny globules. Builders such as sodium silicate do even more – they can prevent corrosion inside washing machines, ensuring that the formula is safe to use.

Like we already mentioned, these chemicals are modern versions of traditional washing agents, fatty acids, lye, and ash.

Alkaline builders are, essentially, soluble salts that neutralize acids. Combined with surfactants, they make a base of laundry detergent suitable for stain removal.

However, they need other ingredients to turn the basic power into a superpower. Modern detergents typically contain medium-strength STPP (sodium tripolyphosphate) as a well-balanced, versatile builder.

But, potent components such as caustic soda (sodium hydroxide) or caustic potash (potassium hydroxide) can also be found in formulas.

Sodium Tripolyphosphate (STPP) powder sample
A sample of Sodium Tripolyphosphate powder by STPP Group


Surfactants – or foamers – such as LABSA (Linear Alkyl Benzene Sulphonic Acid) are added to alkalies as a second principal component to promote their washing ability.

Linear Alkyl Benzene Sulfonic Acid (LABSA) sample
Sample of Linear Alkyl Benzene Sulphonic Acid in a glass vial by STPP Group

Their key role is to enhance the formula’s foaming ability. However, surfactants also work to break up stains further, disbanding the components that don’t dissolve in water easily.

Anionic surfactants don’t always perform well in hard water and need to be supported with a non-ionic surfactant to maximize detergent powder’s cleaning action.

Here we will mention just a few typical examples:

  • One of the most common surfactants on the market is powerful SLES (Sodium Lauryl Ether Sulfate). It’s also one of the few anionic surfactants that lose almost nothing of effectiveness in hard water. 
  • Alpha olefin sulfonate (AOS) is a mild anionic surfactant, characterized by high-foaming and strong emulsifying properties, with a decent performance against minerals. 
  • Fatty Alcohol Polyoxyethylene Ether (AEO 9) belongs to a relatively new generation of multi-functional surfactants with excellent efficiency. It’s great for more sensitive fabrics such as Tencel and viscose.
  • Cocamidopropyl Betaine (CAB) is a liquid amphoteric surfactant. It’s a sulfate-free agent with excellent cleaning and foaming properties, suitable for use as both a primary and secondary surfactant. In addition, it’s an affordable multitasker that can replace harsher anionic agents. 
  • Cocamide diethanolamine (CDA) is one of the gentle, non-ionic surfactants with good stabilizing and conditioning properties.


Next, come the enzymes. Catalytic enzymes changed the laundry detergent industry forever.

These components give the powder detergent its superpowers, targeting particular soils and breaking them into smaller molecules to be washed away easily. 

While different detergent enzymes provide each their own benefits, they all shorten washing time and deliver good results in lower temperatures.

Proteases were the pioneers, the first to be used in mass production.

Lipases and amylases soon followed, paving the road to a whole new generation of enzymes for future washing detergents.

Today, industrial biotechnology generates improved, eco-friendly, industrial-strength laundry detergents with excellent sustainability.

Other supporting ingredients

A range of various pH modifiers, optical brighteners, and other supporting ingredients serves to perfect the formula.

Components like antiredeposition agents serve to prevent soils from settling back on washed clothes. Suds control agents play another vital role in detergents, preventing surfactants from causing problems with a washing machine.

Colorful speckles – brightening agents are visual enhancers, while oxygen bleaches improve the detergency of the mixture.

Colorful Speckles samples
Samples of Colorful Speckles by STPP Group

Finally, processing aids such as sodium sulfate are added to prevent caking and standardize product density.

Perfumes or fragrances are primarily used to cover chemical scents and dirt odors. Each supporting ingredient adds or enhances specific properties, and defines a unique product. 

More about the role of chemical ingredients you can read in our comprehensive article about Liquid detergents, with detailed coverage of the components that both detergent types have in common. 

Key takeaway

Powder detergent contains builders, surfactants, suds, enzymes, and a whole range of supporting and perfecting chemical ingredients. Each component has a role in making the product unique and effective.

The bottom line

Washing powders are still holding strong on the detergent market. They are easy to dose, convenient to use, and deliver great laundry results. Choosing the ideal targeted formula for your personal needs will ensure the best washing results every time. We are happy to help you get there.

In that regard, our customer support team has also provided a set of answers to the most frequently asked questions about powder detergents. It is now composed into a blog post, ready to help you easily find the information you’re looking for.