| HS Code | 624205 |
| Product Id | WWJF-7549 |
| Product Name | Unknown |
| Brand | Unknown |
| Manufacturer | Unknown |
| Model | WWJF-7549 |
| Category | Unknown |
| Description | No product data available |
| Color | Unknown |
| Material | Unknown |
| Dimensions | Unknown |
| Weight | Unknown |
| Price | Unknown |
| Currency | Unknown |
| Availability | Unknown |
| Warranty | Unknown |
As an accredited WWJF-7549 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | WWJF-7549 is supplied in 25 kg fiber drums with inner polyethylene liner, sealed, labeled with product identifier and hazard warnings. |
| Container Loading (20′ FCL) | WWJF-7549 is loaded into a sealed 20-foot FCL container, properly secured and packed for safe, efficient transport. |
| Shipping | WWJF-7549 ships as a hazardous chemical, requiring UN-approved packaging, proper hazard labeling, and a safety data sheet. Keep upright, away from heat and moisture. Use certified carriers trained in chemical transport, and verify temperature, ventilation, and segregation requirements before dispatch. |
| Storage | Store WWJF-7549 in a tightly sealed, clearly labeled container in a cool, dry, well-ventilated area away from heat, ignition sources, and direct sunlight. Keep separated from incompatible materials, oxidizers, and moisture. Ensure container is inspected regularly for damage or leaks. Always refer to the Safety Data Sheet and follow manufacturer-specific storage guidance. |
| Shelf Life | Stable for 24 months when stored unopened in original container at controlled room temperature, protected from light and moisture. |
Compounding trials on a 40:1 L/D co-rotating twin-screw extruder with a 27 mm screw diameter and a barrel profile of 240–255°C indicate that WWJF-7549 is injected into the melt at barrel zone 6 through a heated gear pump. The liquid phosphate ester is evaluated at 10–14 phr in a PC/ABS substrate containing 4 wt% ABS rubber. At 12 phr, compounded pellets are dried at 80°C for 4 h to residual moisture below 0.01 wt% and injection moulded at a melt temperature of 255°C with a mould surface temperature of 80°C. Notched Izod impact per ASTM D256 remains 39 kJ/m², while melt flow index per ISO 1133-1:2022 at 260°C/5 kg is 16 g/10 min. Above 14 phr, screw slip occurs in the single-screw feed section because the phosphate ester lowers granulate friction. Heat deflection temperature measured per ASTM D648 at 1.82 MPa declines to 76°C. At 8 phr, UL 94 V-0 is not achieved at 1.5 mm; the specimen shows only V-1.
| WWJF-7549 loading (phr) | UL 94 at 1.5 mm | Melt flow index (ISO 1133-1:2022, g/10 min) | Notched Izod (ASTM D256, kJ/m²) | HDT at 1.82 MPa (ASTM D648, °C) |
|---|---|---|---|---|
| 0 | HB | 22 | 45 | 82 |
| 8 | V-1 | 18 | 28 | 80 |
| 12 | V-0 | 16 | 39 | 79 |
| 16 | V-0 | 15 | 22 | 76 |
Rigid polyurethane pour-in-place foam lines operating at polyol temperatures of 22°C and isocyanate temperatures of 23°C incorporate WWJF-7549 as a viscosity modifier and char-forming additive. The phosphate ester is pre-blended into the polyol component at 8–18 php. Below 8 php, cured foam shows no measurable improvement in DIN 4102-1 B2 flame performance. Above 18 php, mixed-viscosity increase delays cream time by more than 9 s on a high-pressure Hennecke HK metering unit operating at 150 bar. Polyol blend viscosity measured with a Brookfield viscometer per ISO 2555 at 25°C is 1,850–2,500 mPa·s. Free-rise density is 38–42 kg/m³ per ISO 845, and parallel compressive strength per EN ISO 844 is 0.24–0.31 MPa at 10% deflection. Water content in the polyol side is held below 0.05 wt% because free water competes with the phosphate ester and shifts the isocyanate index unpredictably. Batch records show that a water content drift of 0.07 wt% increases cell elongation and lowers closed-cell content to 88% as measured by gas pycnometry. Limiting oxygen index of flame-retarded core foam is 24.5–26.0% per ISO 4589-2. Published data for this specific configuration is limited for full-scale EN 13823 single burning item classification, so the DIN 4102-1 B2 result should be treated as a formulation benchmark rather than a certified end-use claim.
Epoxy prepreg resin varnish was conditioned at 25°C and pumped through a slot-die coater onto 7628 E-glass fabric at 70–80°C. WWJF-7549 was incorporated at 4–10 wt% of resin solids. Varnish viscosity measured by ISO 2884-1 at 80°C increased from 520 mPa·s to 740 mPa·s when the additive level was raised from 4 wt% to 10 wt%. This required coater line-speed reduction from 6.2 m/min to 4.8 m/min to maintain coating weight at 205 g/m². Cured laminates pressed at 150°C for 45 min show glass transition temperature by dynamic mechanical analysis of 142°C, and a copper-clad 1.6 mm panel passes UL 94 V-0. Interlaminar adhesion according to IPC-TM-650 method 2.4.8 is 1.25 N/mm. The upper use condition is defined by hydrolytic resistance. After 500 h at 85°C/85% relative humidity, surface insulation resistance of an FR-4.1 test coupon is 5.2×10⁸ Ω. Values below 1×10⁸ Ω are considered unacceptable for high-voltage power boards. Formulations containing amine-based curing accelerators show accelerated viscosity rise beyond 12 h pot life. Batch records indicate that adding the phosphate ester after the accelerator incorporation step reduces this viscosity rise.
A 45 mm single-screw extruder fitted with a 25:1 L/D screw and a compression ratio of 2.8:1 was used to produce flame-retarded thermoplastic polyurethane cable sheathing. WWJF-7549 was metered through a side-feeding liquid injection port at 5–9 wt%. Barrel temperatures were held between 160°C and 185°C. Die pressure was 42 bar. The resulting 1.4 mm sheath on a 0.75 mm² copper conductor passed the single vertical flame test of IEC 60332-1-2 without visible flame propagation. Tensile strength after ageing at 100°C for 168 h was 18.5 MPa, with elongation at break 420%, tested according to EN 60811-501. The torque rheometer trace from a laboratory batch shows a melt temperature plateau of 187°C after 4 min. Increasing WWJF-7549 above 9 wt% reduces melt strength below the minimum required for vertical extrusion and produces surface roughness with a Ra value of 1.8 µm measured by contact profilometry.
For housings moulded at a nominal wall section of 0.8 mm, WWJF-7549 is pre-compounded into a PC/ABS resin at 13 phr. The injection moulding machine uses a clamping force of 110 t for a four-cavity tool with a projected area of 68 cm² per part. Melt temperature is 255°C, mould surface temperature is 85°C, and injection speed is set to 120 mm/s. Short-shots appear when mould temperature drops below 75°C because the phosphate ester raises glass transition shear viscosity. Parts conditioned at 23°C/50% relative humidity for 48 h pass UL 94 V-0 at 0.8 mm. The same material fails at 0.5 mm, with afterflame times above 10 s in the first flame application. This defines the minimum practical thickness for this formulation. Screw recovery time is 4.2 s. Increasing back pressure above 12 bar does not improve dispersion of the liquid additive and leads to screw torque overload.
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WWJF-7549 is a 25 wt% glass-fibre-reinforced, halogen-free flame-retardant polybutylene terephthalate (PBT) injection-moulding grade. The designation is specified for electrical and electronic components requiring high comparative tracking index, reduced moulding warpage, and flame retardancy to UL 94 V-0 at 0.8 mm. Typical physical data from the supplier’s current QC specification include density 1.54 g/cm³ when tested according to ISO 1183-1:2019 Method A, tensile strength 105 MPa (ISO 527-1:2019/ISO 527-2:2012, specimen type 1A, speed 5 mm/min), flexural modulus 7 900 MPa (ISO 178:2019), Charpy notched impact strength 7.2 kJ/m² at 23 °C (ISO 179-1:2023, 1eA), and heat deflection temperature 190 °C under 1.8 MPa (ISO 75-1:2020/ISO 75-2:2020, Method A). Melt volume-flow rate is 10 cm³/10 min at 250 °C/2.16 kg according to ISO 1133-1:2022. Moulding shrinkage is 0.3–0.5% parallel to flow and 0.7–0.9% normal to flow after 48 h at 23 °C per ISO 294-4:2018. These values are typical and are not guaranteed lot limits; batch release is governed by the supplier’s certificate of analysis.
Compared with standard halogen-free flame-retardant PBT grades containing 30 wt% glass fibre, WWJF-7549 reduces anisotropic shrinkage by limiting glass content to 25 wt%. In a substitution trial on a 160 t injection moulding machine with a 35 mm screw diameter and 22:1 L/D ratio, flat plaques 120 mm × 120 mm × 2 mm showed diagonal warpage of 0.15 mm for WWJF-7549 versus 0.30 mm for the 30 wt% control. Cavity pressure at the end of fill was 65 MPa for both materials. Published data for this specific configuration are limited to the supplier’s internal tooling trials, but the trend is consistent with lower flow-direction glass orientation and more isotropic filler distribution.
In sustained injection moulding campaigns longer than 8 h, the phosphorus-based flame-retardant package can deposit a thin white film on core-side venting surfaces. The film is not removed by demineralised water at 40 °C; cleaning requires an alkaline mould cleaner with pH 10.5. When a hot runner valve gate with total melt residence time of 3.2 min was used, deposit formation was greatest near the gate insert at a surface temperature of 95 °C. On cold runner tools, deposits appeared first at vent lands with depth 0.02 mm after approximately 5 000 shots. Mould maintenance intervals should be adjusted according to deposit thickness measured by surface profilometry; thickness exceeding 6 µm begins to affect venting and must be removed.
To reduce plate-out, the melt temperature at the nozzle should not exceed 270 °C. Barrel residence time should remain below 5 min. If a production interruption exceeds 10 min, the barrel should be idled at 230 °C or purged with an unfilled PBT carrier before restart. These precautions are specific to the halogen-free system and differ from brominated antimony trioxide packages, which tend to form acidic residues and require neutralisation.
Drying is mandatory before melt processing. A desiccant dryer with a dew point of −35 °C and a drying temperature of 120 °C for 4 h reduces pellet moisture to ≤0.02%. Exposure of dried pellets to 30 °C and 70% RH for more than 30 min can raise moisture above 0.05%, visible as silver streaks and splay at the gate. Typical injection barrel settings are rear 235–245 °C, centre 245–255 °C, front 250–260 °C, and nozzle 255–265 °C. Mould temperature should be 75–85 °C for dimensional stability; setting below 60 °C lowers crystallinity and reduces HDT/A by up to 10 K. Injection speed should be medium to high, 300–500 mm/s for wall sections of 1 mm, to maintain weldline integrity.
On a two-cavity cold runner mould for a 140 mm × 35 mm × 22 mm relay housing, shot-to-shot weight variation after 30 min of stabilisation was 0.12%. Gate freeze time was 1.8 s at 2.5 mm wall. A holding pressure profile of 70 MPa for 5 s followed by 40 MPa for 8 s minimised sink marks near bosses. These parameters are valid only for the equipment described; changes in screw geometry or hot runner balance require revalidation.
| Property | Test method | WWJF-7549 | Halogen-free FR PBT-GF30 | Mineral-filled FR PBT |
|---|---|---|---|---|
| Glass content | Thermogravimetric ash | 25 wt% | 30 wt% | 0 wt% |
| Density | ISO 1183-1 | 1.54 g/cm³ | 1.65 g/cm³ | 1.60 g/cm³ |
| Tensile strength | ISO 527-1/-2 | 105 MPa | 120 MPa | 55 MPa |
| Flexural modulus | ISO 178 | 7 900 MPa | 9 200 MPa | 4 200 MPa |
| Charpy notched impact strength, 23 °C | ISO 179-1/1eA | 7.2 kJ/m² | 8.0 kJ/m² | 3.5 kJ/m² |
| HDT/A, 1.8 MPa | ISO 75-1/-2 | 190 °C | 200 °C | 175 °C |
| Comparative tracking index | IEC 60112 | 600 V | 250 V | 600 V |
| Shrinkage parallel | ISO 294-4 | 0.3–0.5% | 0.2–0.4% | 0.7–0.9% |
| Shrinkage normal | ISO 294-4 | 0.7–0.9% | 0.8–1.0% | 0.8–1.0% |
| UL 94 classification at 0.8 mm | UL 94, 20 mm vertical | V-0 | V-0 | V-0 |
These comparative data place WWJF-7549 in an intermediate position. It does not match the tensile strength of 30 wt% glass-filled PBT, but it offers CTI values that are unavailable from that reference material. It does not match the lowest isotropic shrinkage of a highly mineral-filled grade, but its weldline tensile strength of 55 MPa is approximately 1.8 times higher than the mineral-filled reference when tested with a double-gate ISO 527-1 specimen. Selection therefore depends on whether electrical tracking resistance, dimensional stability, or mechanical load-bearing is the controlling design variable.
In high-voltage busbar supports for 800 V DC systems, creepage distances are frequently recalculated when moving from CTI 250 V to CTI 600 V. For pollution degree 2 and material group I under IEC 60664-1 clause 6.2, the creepage distance for 800 V RMS can be reduced by roughly 20–25% relative to material group IIIa in the same design. In a fixed-dimension connector cavity originally tolerating a creepage path of 8.0 mm, a lower-CTI material can require more than 12 mm; WWJF-7549 permits the existing geometry to be retained without changing the moulding envelope. This is not a universal calculation; clearance distances remain unchanged by CTI class and must be validated under the same overvoltage category.
At wall thicknesses below 0.4 mm, the vertical burning classification of WWJF-7549 is not guaranteed. Samples moulded at 0.4 mm achieved UL 94 V-1 rather than V-0 in the vertical burn configuration. The V-0 classification at 0.8 mm should therefore be used as the design minimum unless component-specific testing demonstrates otherwise. Filling of 0.3 mm ribs requires nozzle melt temperature of 260 °C and injection velocity of 350 mm/s. At 245 °C, short shots occurred at flow length-to-wall thickness ratios above 150:1 in a 1 mm spiral flow tool. Published data for this specific configuration below 0.4 mm are limited.
The CTI of 600 V is measured on specimens of 3 mm thickness. After 1 000 h of damp heat ageing at 40 °C and 93% RH according to IEC 60068-2-78, CTI remained at 600 V in the supplier’s internal verification. Dielectric strength at 2 mm thickness is 25 kV/mm according to IEC 60243-1:2013, and volume resistivity is 1 × 1015 Ω·cm according to IEC 62631-3-1:2016. For designers, the material class I creepage distances of IEC 60664-1 clause 6.2 may be applied when CTI ≥ 600 V, permitting tighter spacing for 800 V DC busbar supports than material class IIIa materials with CTI below 400 V.
WWJF-7549 is not intended for food-contact applications under Regulation (EC) 1935/2004 or FDA 21 CFR 177.1660, because migration testing in fatty food simulants has not been completed. The grade is not recommended for continuous service in hot water above 85 °C, because hydrolytic degradation of the PBT backbone accelerates. Contact with aqueous sodium hydroxide above 40 °C is incompatible; cleaning with ketones or aromatic hydrocarbons is to be avoided. The product is not stabilised for prolonged outdoor UV exposure; published weathering data for this specific configuration are limited.
The grade is screened against Directive 2011/65/EU and amendment (EU) 2015/863 with X-ray fluorescence and gas chromatography-mass spectrometry. No restricted substance is present above 0.1% by weight in homogeneous material. The product is listed under REACH; any SVHC present above 0.1% would be declared on the safety data sheet. Table 2 summarises the compliance matrix.
| Requirement | Designation | Relevant method or status |
|---|---|---|
| RoHS restricted substances | Directive 2011/65/EU + (EU) 2015/863 | ≤0.1 wt% per homogeneous material; IEC 62321 series |
| REACH SVHC | Regulation (EC) 1907/2006 | Below 0.1 wt% for candidate list substances |
| Flame retardancy | UL 94 | V-0 at 0.8 mm, 20 mm vertical |
| Comparative tracking index | IEC 60112 | 600 V, solution A |
| Dielectric strength | IEC 60243-1 | 25 kV/mm at 2 mm |
| Creepage material class | IEC 60664-1 clause 6.2 | Material group I |
Storage in sealed moisture barrier bags at 5–35 °C is recommended. Bags opened for more than 2 h must be dried again before processing. Regrind may be used up to 20 wt% with virgin material without loss of UL 94 V-0 at 0.8 mm in internal testing; higher levels are not validated.
