| HS Code | |
| Chemical Formula | C3H6N6 |
| Molecular Weight | 126.12 g/mol |
| Appearance | White crystalline powder |
| Odor | Odorless |
| Density | 1.57 g/cm³ |
| Melting Point | 345 °C (decomposes) |
| Decomposition Temperature | 345 °C |
| Solubility In Water | 3.1 g/L at 20 °C |
| Solubility In Organic Solvents | Insoluble in most organic solvents |
| Ph | Weakly alkaline (saturated aqueous solution) |
| Pka | 5.0 (conjugate acid) |
| Crystal Structure | Monoclinic |
| Logp | -1.37 |
| Vapor Pressure | <0.1 mPa at 20 °C |
| Flash Point | >300 °C |
| Autoignition Temperature | >600 °C |
As an accredited Melamine factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Melamine supplied in sealed 25 kg woven polypropylene bags with inner polyethylene liners, stacked on pallets for industrial handling. |
| Container Loading (20′ FCL) | Approx. 20 MT Melamine in 25 kg bags, palletized, shrink-wrapped, loaded into 20′ FCL, securely stowed to prevent shifting during transit. |
| Shipping | Melamine is typically shipped as a non-hazardous, non-DG solid in 25 kg bags, FIBCs, drums, or bulk. Store cool, dry, and ventilated, keeping containers sealed and away from oxidizers and moisture. Avoid dust generation, use appropriate PPE, and verify carrier and local transport regulations before shipment. |
| Storage | Store melamine in a cool, dry, well-ventilated area away from direct sunlight and moisture. Keep containers tightly closed and properly labeled. Prevent dust generation and accumulation. Separate from strong oxidizers, acids, and other incompatible materials. Use appropriate secondary containment where required. Follow local regulations and safety data sheet recommendations. Ensure good ventilation and avoid inhalation or skin contact during handling. |
| Shelf Life | Melamine is chemically stable; stored dry, sealed, and at room temperature, it has an indefinite shelf life with no typical expiration. |
| Parameter | Overlay paper | Decorative paper | Core kraft paper |
|---|---|---|---|
| Resin solids at application | 55–65 wt% | 55–65 wt% | 45–55 wt% |
| Resin pick-up on dry paper | 60–70 wt% | 50–60 wt% | 30–40 wt% |
| Residual volatiles after drying | 6–8 wt% | 6–8 wt% | 5–7 wt% |
| Press temperature | 150–165°C | 135–150°C | |
| Press pressure | 7–10 MPa | 7–9 MPa | |
| Component | Low expansion | Medium expansion | High expansion |
|---|---|---|---|
| Ammonium polyphosphate | 20 wt% | 25 wt% | 30 wt% |
| Melamine | 10 wt% | 15 wt% | 20 wt% |
| Pentaerythritol | 10 wt% | 12 wt% | 15 wt% |
| Acrylic binder | 35 wt% | 30 wt% | 25 wt% |
| Titanium dioxide | 8 wt% | 6 wt% | 5 wt% |
| Additives and water | to 100 wt% | to 100 wt% | to 100 wt% |
Competitive Melamine prices that fit your budget—flexible terms and customized quotes for every order.
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Melamine, 1,3,5-triazine-2,4,6-triamine, is a white crystalline solid supplied under CAS 108-78-1 with molecular formula C₃H₆N₆ and molecular weight 126.12 g/mol. The dry compound contains 66.6% nitrogen by weight and decomposes in the range 345–354 °C at atmospheric pressure. Industrial grades are manufactured predominantly from urea and are controlled for purity, particle size, moisture, and slurry pH; these variables influence methylolation rate, dusting propensity, and storage stability. Table 1 lists a representative specification for resin-grade melamine. The values are grade-dependent and do not replace the supplier certificate of analysis.
| Parameter | Representative value | Test basis |
|---|---|---|
| Melamine purity | ≥ 99.0% by weight | HPLC, area normalization |
| Moisture | ≤ 0.10% | Karl Fischer coulometry |
| Ash content | ≤ 0.02% | Muffle furnace, 600 °C |
| pH, 10 g/L aqueous suspension | 7.5–9.5 | Suspension pH meter |
| Median particle size d50 | 20–60 μm | Laser diffraction, ISO 13320 |
| Particle size d90 | ≤ 100 μm | Laser diffraction, ISO 13320 |
Particle size distribution affects wetting and dispersion. A d50 of 20–60 μm and d90 of ≤ 100 μm are typical for resin and adhesive grades, while fine grades with d50 below 10 μm are specified for coatings and some flame-retardant dispersions. Regardless of grade, melamine is only sparingly soluble in water at 20 °C; solubility increases with temperature and under acidic conditions because of hydrolysis.
Production-scale resin reactors of 10–30 m³ with reflux condensers and internal cooling coils are used to condense melamine with aqueous formaldehyde. The initial methylolation is performed at 75–85 °C and pH 8.0–9.0; the exotherm is controlled by staged melamine addition and jacket cooling. After methylolation, condensation proceeds at pH 5.0–6.5 until water dilutability and gel time meet the target. Over-condensation can reduce gel time below 100 s at 100 °C; the batch is then cooled below 30 °C and adjusted to pH 9.0–9.5 to limit further advancement. Free formaldehyde in laminating resin is typically below 0.3%, but lower limits are required for low-emission wood panel adhesives.
The F/M ratio is not simply stoichiometric. Although the triazine ring carries three primary amine groups, steric hindrance and equilibrium methylolation prevent full substitution of all six active hydrogens under typical industrial conditions. Higher F/M ratios reduce free melamine and improve water dilutability but increase free formaldehyde and moisture sensitivity. Lower F/M ratios improve storage stability but can cause precipitation and uneven crosslinking in the finished laminate. The processing window between cloud point and over-condensation narrows as reactor solids increase above 60%.
Urea-formaldehyde resins are lower in cost and cure at lower temperatures, but their cured networks are more susceptible to hydrolytic degradation and formaldehyde release. Melamine-formaldehyde adhesives provide higher crosslink density and better moisture resistance; comparative ASTM D570 water absorption and ISO 75 heat deflection data show the performance shift. In particleboard and medium-density fiberboard, melamine is often added as a co-monomer rather than a full replacement because of cost and press-cycle constraints. The higher cure temperature of melamine-containing resins can reduce line speed if press time is not adjusted.
| Parameter | Melamine | Urea | Benzoguanamine |
|---|---|---|---|
| Theoretical active hydrogens | 6 | 4 | 4 |
| ASTM D570 water absorption, cured resin film | 1.5–3.0% | 4–10% | formulation-dependent |
| ISO 75 heat deflection temperature | 150–190 °C | 90–120 °C | lower than melamine, formulation-dependent |
| Primary cost driver | triazine monomer cost | low-cost commodity | specialty monomer cost |
| Typical cure temperature in adhesive applications | 120–140 °C | 90–110 °C | 130–160 °C |
Benzoguanamine is a further alternative with lower theoretical reactive hydrogens than melamine and a phenyl substituent that reduces network density but improves organic solubility. Dicyandiamide and phenol-formaldehyde systems are chemically distinct and are selected for different cure chemistries. None of these alternatives reproduces the combined surface hardness, heat resistance, and stain resistance of melamine-formaldehyde at equivalent film weight.
In high-pressure laminate manufacture, alpha-cellulose decorative paper is impregnated with melamine-formaldehyde resin to resin contents of 50–70% by dry weight and B-staged in air-float ovens. The prepreg residual volatile content is controlled between 5% and 8%. The layup is pressed in multi-opening hydraulic presses with 15–20 daylights at platen temperatures of 140–160 °C and specific pressures of 6–10 MPa. Platen parallelism is maintained within 0.1 mm/m; deviations can produce thickness variation and localized under-cure at the panel edges.
The stable process window is bounded on the low side by insufficient cure. If platen temperature falls below 135 °C or dwell time is too short, the degree of cure may be insufficient for ISO 4586-2 requirements for stain resistance, steam resistance, and surface wear. Residual methylol groups remain hydrophilic and can produce microcracking and haze after water exposure. On the high side, platen temperatures above 165 °C or excessive dwell can embrittle the surface and shift color. Moisture content above 8% in the prepreg stack can generate steam blisters during pressing.
In production-scale impregnation lines, wet pickup is monitored gravimetrically. A swing of more than ±2% in wet pickup alters final surface appearance and abrasion resistance. Catalyst level is adjusted with lower-cost paper grades and higher line speeds, but the adjustment reduces press latitude. Multi-daylight packs are assembled with release papers and mirror-finish press plates. Plate cleanliness and release-agent selection affect surface gloss and defect density. Dust or fiber between plates can create local pressure points that degrade laminate performance under ISO 4586-2 abrasion testing. Published data for specific catalyst-to-resin ratios is limited; mill-scale trials are typically required to define the exact window for a given paper and press combination.
Melamine decomposes in the range 300–400 °C with endothermic release of inert nitrogen gas. In intumescent coatings, it is combined with ammonium polyphosphate and pentaerythritol; the melamine acts as a blowing agent and contributes to char expansion. Published formulations commonly use 20–40 wt% melamine in dry film solids, although published data for specific polymer grades is limited. In flexible polyurethane foam, addition levels of 10–30 phr are reported to improve flammability performance in small-scale tests such as UL 94, but the effect on tensile strength, elongation, and compression set must be evaluated at each loading.
The material does not melt into the polymer matrix, which imposes processing constraints. Particle size must be controlled because coarse fractions above 100 μm can block airless spray tips in coatings and can increase roll defects in thin films. High loadings increase viscosity and reduce film cohesion. Melamine is a halogen-free flame retardant and does not provide plasticizing action; its efficiency depends on the char-forming co-synergists and the polymer decomposition pathway.
Melamine-formaldehyde molding compounds are processed by compression or transfer molding at 150–170 °C and 20–40 MPa. Filled compounds exhibit high surface hardness and hot-water resistance, but they are more brittle than filled urea-formaldehyde compounds. Electrical properties are assessed under IEC 60243 for dielectric strength and ASTM D257 for volume and surface resistivity, depending on the part specification.
Silo storage of melamine powder requires combustible-dust management. Baghouses, silo vents, and conveying lines should comply with NFPA 652 and applicable ATEX provisions. Bulk material should be stored sealed at ambient temperature below 35 °C and relative humidity below 60% to prevent caking. Under these conditions, hydrolysis to cyanuric acid and ammonia is negligible. The rate increases under acidic conditions or hydrothermal exposure; therefore, melamine should not be stored near strong acids or steam. Dust accumulations on hot surfaces should be prevented because decomposition can liberate ammonia.
Sulfomethylated melamine-formaldehyde condensates are used as high-range water reducers in cementitious systems. The admixture disperses cement particles by electrostatic repulsion, allowing water reduction and improved early strength. Dosages of 0.5–2.0% by weight of cement are typical in mortars and self-leveling underlayments. Performance is evaluated under ASTM C494 for Type F or Type G water-reducing admixtures; specific dosage depends on cement fineness, supplementary cementitious materials, and placement temperature. Compared with naphthalene-derived high-range water reducers, sulfomethylated melamine generally produces less setting retardation at equivalent slump, but published comparative data for specific cement compositions is limited. The product is supplied as an aqueous solution or spray-dried powder.
Regulatory classification and registration must be confirmed for the specific grade and jurisdiction. For European Union applications, obligations under REACH apply. Food-contact uses fall within Commission Regulation (EU) No 10/2011 migration limits for plastics when used in laminated surfaces or coatings. In the United States, resinous and polymeric coatings may be subject to FDA 21 CFR 175.300 where applicable. Compliance requires batch-specific documentation because residual melamine and formaldehyde migration depend on cure conditions, molar ratio, and laminate construction.
