Sodium Tripolyphosphate (STPP) – Industrial-Grade Sodium Triphosphate

CAS No.: 7758-29-4 | Chemical Formula: Na₅P₃O₁₀ | Purity: ≥94.0%

Sodium Tripolyphosphate, commonly known as STPP or sodium triphosphate, is a high-performance inorganic polyphosphate widely used as a detergent builder, water softener, dispersing agent, emulsifier and metal-ion sequestrant. Manufactured through high-temperature thermal polymerization of refined soda ash and high-quality phosphoric acid, industrial-grade STPP is available as a white, free-flowing fine powder or uniform crystalline granules.

STPP is highly soluble in both cold and hot water and provides excellent calcium and magnesium ion chelation, water softening, pH buffering, soil dispersion and emulsification performance. By binding hard-water minerals such as calcium, magnesium and iron, sodium tripolyphosphate improves formulation efficiency and minimizes the negative effects of water hardness on cleaning, ceramic processing, metal treatment and industrial water systems.

Our industrial-grade STPP is manufactured using closed, automated production systems and stringent quality-control procedures. Controlled polymerization and comprehensive intermediate testing ensure consistent P₂O₅ content, low water-insoluble matter and controlled heavy-metal levels, making the product a reliable bulk phosphate raw material for global industrial applications.

Sodium Tripolyphosphate Specifications

Key Properties and Functional Benefits

Excellent Water Softening: STPP effectively complexes calcium and magnesium ions responsible for water hardness, improving the performance of detergents and other aqueous formulations.

Powerful Metal-Ion Sequestration: Its strong chelating capability helps control Ca²⁺, Mg²⁺, Fe³⁺ and other metal ions that can negatively affect industrial formulations and processing systems.

Superior Soil Dispersion: STPP disperses suspended dirt, mineral particles and particulate contaminants, helping prevent their re-deposition on cleaned surfaces.

Emulsification Performance: It assists in emulsifying oils and greasy contaminants, making it particularly valuable in detergent and industrial degreasing formulations.

pH Buffering: STPP contributes to maintaining favorable alkaline conditions in cleaning and processing formulations, supporting consistent product performance.

Low Water-Insoluble Content: The low insoluble residue minimizes the risk of sedimentation, filtration problems and dosing-system blockage.

Major Industrial Applications of STPP

1. Synthetic Detergent & Industrial Cleaning

The synthetic detergent industry is one of the largest consumption sectors for sodium tripolyphosphate. STPP functions as a multifunctional detergent builder in laundry powders, industrial cleaning products, liquid detergents and heavy-duty degreasers.

It binds calcium and magnesium ions in hard water, thereby improving water softness and enhancing surfactant effectiveness. At the same time, STPP promotes oil emulsification and particulate-soil dispersion while reducing the re-deposition of removed dirt onto fabric or hard surfaces.

These properties make STPP an important raw material for laundry detergent formulations, institutional cleaners, industrial degreasers and heavy-duty cleaning chemicals.

2. Ceramic, Tile & Sanitaryware Manufacturing

Sodium tripolyphosphate is widely used as a high-efficiency dispersant and deflocculant for ceramic slips, glazes and slurry systems.

Proper STPP dosage can reduce slurry viscosity, improve fluidity and optimize the water-to-solid ratio of ceramic raw materials. Better slurry flow and mold filling can contribute to improved green-body processing, reduced drying and firing defects, and more consistent glaze distribution.

STPP is therefore valuable in the production of ceramic tiles, porcelain products, sanitaryware and other ceramic materials where slurry stability and processing efficiency are critical.

3. Metal Surface Treatment & Electroplating

STPP is used as an additive in alkaline metal cleaning and degreasing formulations before electroplating, phosphating, painting and other surface-treatment processes.

Its water-softening, sequestration, emulsification and dispersing properties assist in removing mineral oils, grease, oxide residues and other contaminants from steel, iron, aluminum and zinc surfaces. Effective pretreatment helps improve substrate cleanliness and supports better adhesion of subsequent plating or coating layers.

4. Industrial Water Treatment & Scale Control

STPP can function as an economical water-conditioning and scale-control agent in selected industrial water-treatment applications, including circulating-water systems, boilers and process-water systems.

By complexing hardness ions, STPP helps reduce the availability of calcium and magnesium that can contribute to mineral deposits. Properly designed formulations can therefore help minimize scaling on pipelines, heat-transfer surfaces and process equipment.

Application suitability and dosage should be determined according to water chemistry, operating conditions and the specific treatment system.

5. Textile, Printing & Dyeing Applications

In textile processing, STPP can be used as a water-softening, dispersing and processing auxiliary in pretreatment and dyeing-related formulations.

It helps control hardness ions, promote more uniform dispersion of dye particles and support consistent processing conditions. This can contribute to improved dye distribution and reduced processing defects caused by hard-water interference.

Why Choose Our Industrial-Grade STPP?

Consistent P₂O₅ Performance

A controlled high-temperature polymerization process helps maintain stable P₂O₅ content and consistent functional performance from batch to batch, supporting reliable large-scale manufacturing.

Powder and Granule Options

Available in fine powder and uniform granular forms to accommodate different production and handling requirements. Powder is suitable for automated high-speed blending, while granules can help reduce dust during manual feeding and batching.

Low Water-Insoluble Content

Water-insoluble matter is controlled at ≤0.1%, helping reduce sedimentation and minimizing potential blockage in filtration, pipelines and automated dosing systems.

Quality Documentation for International Trade

Export shipments can be supported with essential technical and compliance documentation, including Certificate of Analysis (COA), Safety Data Sheet (SDS/MSDS) and factory qualification documents, subject to destination-market requirements.

Reliable Bulk Supply

Large-scale continuous production supports sample orders, trial quantities, containerized shipments and long-term bulk supply programs, with production and delivery schedules coordinated according to customer requirements.

Packaging & Storage

The standard packaging option is a 25 kg woven polypropylene bag with an inner PE liner, designed to protect the product from moisture during storage and transportation. Jumbo bags and customized bulk packaging can also be arranged for high-volume orders.

Store sodium tripolyphosphate in a cool, dry and well-ventilated indoor warehouse. Keep packaging tightly sealed and protected from rain, water leakage, excessive humidity, direct sunlight, high temperatures, strong acids and incompatible corrosive chemicals.

Avoid prolonged exposure to moisture and excessive stacking pressure to minimize the risk of product agglomeration and packaging damage.

Under appropriate sealed and dry storage conditions, the recommended shelf life is up to 12 months.

Safety & Handling Information

Sodium tripolyphosphate is a common inorganic phosphate material and is generally non-flammable and non-explosive. Dust generated during handling may cause temporary respiratory discomfort, while prolonged or repeated skin contact may cause dryness or mild irritation.

During unpacking, conveying, weighing and feeding operations, personnel should use appropriate dust protection, protective gloves, safety eyewear and suitable industrial PPE in accordance with the applicable workplace risk assessment and local regulations.

Safety Data Sheets (SDS/MSDS) can provide detailed information regarding handling, storage, first-aid measures, accidental release response and other safety requirements.

Transportation classification should be verified against the current applicable regulations and shipping documentation for the destination market.

Bulk Sodium Tripolyphosphate Supplier for Global Industrial Applications

Our industrial-grade Sodium Tripolyphosphate (STPP), CAS 7758-29-4, is designed for manufacturers and distributors requiring reliable phosphate raw materials for detergent, ceramic, metal-treatment, water-treatment and textile-processing applications.

With controlled production, consistent specifications, flexible powder and granular grades, export documentation and scalable bulk supply capabilities, our STPP provides a practical solution for industrial formulation, manufacturing and international distribution.