Sodium Polyphosphate
Sodium Polyphosphate is the long-chain crystalline polymer of sodium metaphosphate with the formula (NaPO3)n, where n typically ranges from several hundred to several thousand phosphate units.
The salt forms a white crystalline powder that dissolves slowly in water to give a clear, mildly acidic solution. Unlike the glassy hexametaphosphate, sodium polyphosphate is a true crystalline polymer with regular chain structure, and is sometimes labelled Maddrell's salt or insoluble sodium metaphosphate in technical literature.
We source bulk Sodium Polyphosphate from top China manufacturers for our partners. The manufacturer is in Jiangsu. A smaller requirement can ship in a combined container with other ingredients.
Please send the grade you need, the volume and your destination port, and we will come back with a solution and a price.
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- Packaging
- 25 kg kraft paper bag with PE inner liner
- ISO 9001
- HACCP
- Halal
- Kosher
Specifications
| Item | Specification |
|---|---|
| Appearance | White powder or glassy flakes |
| Assay (as NaPO₃) | ≥ 68.0% (as P₂O₅) |
| pH (1% solution) | 5.8-7.3 |
| Water Insolubles | ≤ 0.1% |
| Loss on Ignition | ≤ 1.0% |
| Iron | ≤ 50 mg/kg |
| Heavy Metals (as Pb) | ≤ 10 mg/kg |
| Arsenic | ≤ 3 mg/kg |
| Fluoride | ≤ 10 mg/kg |
Common Markets Grades
Sodium polyphosphate is graded by chain length, crystalline phase, and dissolution rate.
Standard food-grade material conforms to E 452(iv) and FCC purity specifications with minimum 95 percent P2O5 expressed as (NaPO3)n.
Insoluble sodium polyphosphate (IMP), the Maddrell's salt form, is used as an abrasive in toothpaste and as a slow-release phosphate in dental and pharmaceutical applications.
Soluble sodium polyphosphate, with a shorter average chain length and faster hydration, is used in food, dairy, and meat applications where rapid sequestration is required.
Particle size distribution is the secondary specification axis, ranging from sub-50 micron fines for toothpaste to coarse granules for industrial batching.
Applications
- Meat and poultry brines as a high-capacity sequestrant of calcium and magnesium
- Processed cheese and analogue cheese as a slow-release emulsifying salt
- Dairy: cream, evaporated milk, and UHT systems for protein stability
- Toothpaste: the insoluble crystalline form as a polishing and remineralising abrasive
- Industrial detergent and dish-cleaning builders
- Boiler-water and cooling-tower scale inhibitors
- Ceramic slip deflocculation
- Pet food, especially canned and pouched products
- Surimi manufacture for protein extraction
- Paper-industry pulp dispersion and pitch control
China Manufacturers of Sodium Polyphosphate
Top Sodium Polyphosphate manufacturers in China.
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
How We Help Source Sodium Polyphosphate
Direct Factory Sourcing
We run the whole process: selecting the manufacturer from the top Chinese food ingredient producers, negotiating the price, verifying quality, and coordinating the logistics. You deal with us instead of with several factories at once.
Original Packaging and Documents from the Manufacturer
The manufacturer sends your Sodium Polyphosphate out of its own factory in the original packing, through to your destination port. The COA, COO, MSDS, TDS and any certifications reach you from the manufacturer as well.
Free Samples and Lead Time
We send 100 to 500 g free for your own laboratory to test and you cover only the courier, usually within 2 to 3 working days. ETD is usually within 7 to 15 days once the order is confirmed, and we check that date against the factory's own manufacturing schedule before we give it to you.
Combined Shipment
We can load Sodium Polyphosphate together with other ingredients such as Sodium Tripolyphosphate, Sodium Hexametaphosphate and TetraSodium Pyrophosphate into one 20' FCL. If your quantity is small, we can also ship LCL.
Regulatory Status
Sodium polyphosphate is approved as a food additive in major regulated markets.
The European Union lists it as E 452(iv) within the polyphosphate sub-family of phosphate additives. The U.S. FDA recognises it under 21 CFR 182.1810 (GRAS) and within the general phosphate sequestrant entries.
JECFA includes sodium polyphosphate within its group evaluation of phosphate additives.
FCC and Ph. Eur. monographs cover identity, assay, and impurity limits. Halal and Kosher certifications exist.
The insoluble Maddrell-phase grades used in toothpaste have separate dental and pharmaceutical specifications that focus on particle size, abrasivity (RDA), and dissolution behaviour rather than food-additive purity criteria.
Manufacturing Process
Sodium polyphosphate is produced by extended thermal condensation of monosodium orthophosphate, followed by controlled cooling that favours a regular crystalline structure rather than a glassy or cyclic phase.
Monosodium orthophosphate is prepared by partial neutralisation of food-grade phosphoric acid with sodium carbonate at a 1:1 mole ratio. The solution is concentrated and dried.
The dried salt is calcined in continuous furnaces at 600 to 750 degrees Celsius for extended dwell times that allow the phosphate chains to grow to several thousand units.
The cooling step distinguishes sodium polyphosphate from sodium hexametaphosphate. Slow cooling through the crystallisation window allows the linear chains to align into a regular crystalline lattice, producing the Maddrell phase. Rapid quenching of the same molten material would yield SHMP glass instead.
The cooled solid is milled, sieved, and tested by X-ray diffraction to confirm the crystalline phase and by chain-length analysis to verify the degree of polymerisation.
