Dongguan Xinsu Source PC/ABS FR5260 is a flame-retardant polycarbonate/acrylonitrile-butadiene-styrene blend supplied in pellet form for injection molding and thin-wall structural components. The grade is positioned for electrical enclosures, power-distribution housings, and battery-management subassemblies where UL 94 V-0 at 1.5 mm and high notched Izod impact at ambient temperature are required. In this density class, the flame-retardant function is typically obtained from a phosphorus-based additive system; the exact chemistry and additive loading should be verified on the supplier lot certificate. The material is not intended for food-contact or medical-implant use unless application-specific compliance documentation is issued.

What datasheet envelope defines the mechanical performance of FR5260?

Typical property values reported for this flame-retardant PC/ABS class appear in Table 1. These values are representative of the supplier datasheet class, are not design allowables, and should be confirmed by lot-specific certificate of analysis. Conditioning follows ISO 291 at 23°C and 50% relative humidity unless noted.

The reported melt volume-flow rate of 15 cm³/10 min at 260°C/5 kg indicates a medium-flow material suited for housing walls with flow length-to-thickness ratios up to 120:1. Tensile yield of 55 MPa at 23°C and flexural modulus of 2400 MPa provide sidewall rigidity without excessive filling pressure. The transition from ductile to brittle impact behavior occurs between 23°C and -30°C; therefore, impact-critical features such as snap-fit tabs, bosses for self-tapping screws, and living hinges should be tested at the lowest service temperature. The notched Izod value of 45 kJ/m² at 23°C is higher than many general-purpose PC/ABS FR grades, but lower than unreinforced PC/ABS non-FR impact grades, which can exceed 60 kJ/m². This difference arises from the flame-retardant additive phase acting as a stress concentrator.

Rheological characterisation for this viscosity class under capillary flow indicates shear thinning with a power-law index of approximately 0.3 to 0.4 between 100 s⁻¹ and 1000 s⁻¹. The pressure drop across a 1.5 mm wall section is sensitive to gate diameter; a 0.8 mm gate can reduce effective flow length by 15% compared with a 1.2 mm gate due to shear heating and earlier freeze-off. In multi-cavity tools with more than 8 cavities, cavity-to-cavity filling imbalance exceeding 10% has been observed when runner balancing is not performed with melt-flow simulation. Weld lines in PC/ABS FR occur where flow fronts meet downstream of core pins; their tensile strength retention is typically 40% to 60% of the bulk tensile yield. To reduce visible weld lines, sequential valve gating can be used, but the associated melt residence time must remain below 5 minutes to avoid degradation.

Pre-drying is mandatory before injection molding. Desiccant drying at 80°C to 90°C for 4 h to 6 h reduces moisture to below 0.02% by weight; higher residual moisture causes splay, surface silver streaks, and molecular weight reduction in the polycarbonate phase. Production-scale reciprocating-screw injection molding machines with screw diameters of 30 mm to 40 mm and L/D ratios of 20:1 to 22:1 are suitable. Melt temperature should be controlled at 250°C to 270°C, with the nozzle set no higher than 280°C to prevent degradation of the phosphate flame retardant. Mold temperature should be held at 60°C to 80°C. In hot-runner systems, residence time at melt temperature should not exceed 5 minutes, and dead spots must be eliminated; otherwise, black specks and viscosity variance appear. On a 250-ton hydraulic injection molding machine with a 40 mm screw, typical injection pressure for a 1.5 mm wall enclosure is 70 MPa to 90 MPa hydraulic pressure, corresponding to approximately 100 MPa to 130 MPa melt pressure. Melt cushion should be maintained at 3 mm to 6 mm. Screw back pressure of 0.5 MPa to 1.0 MPa improves dispersion of the flame-retardant package without excessive frictional heat. In a hot-runner manifold, the pressure drop across a 4-drop system can be 8 MPa to 15 MPa depending on gate diameter; if the pressure drop exceeds 20 MPa, melt temperature rise and FR degradation risk increase. Batch-to-batch viscosity variation in flame-retardant PC/ABS is commonly less than 5% relative MVR when the supplier uses twin-screw extrusion with side-fed flame-retardant masterbatch and vacuum venting at -0.08 MPa or lower. Nonetheless, after silo changes or raw-material lot shifts, shot weight and melt pressure should be verified because phosphate-based additives are sensitive to moisture and shear history. Combination with amine-based mold release agents or basic hot-runner cleaning compounds is not recommended; amines catalyze polycarbonate chain scission and can promote stress cracking. Regrind levels should be kept below 20% unless the end-use certification permits higher content; above 20%, impact and flame retardance may shift outside the certified window.

In production trials for thin-wall enclosures, the most frequently observed failure modes are gate blush, jetting, halo around hot-runner drops, and silver streaking due to moisture. Gate blush is reduced when the gate diameter is at least 0.8 mm and the injection velocity is profiled to descend from 80 mm/s to 30 mm/s. Jetting in a 1.2 mm wall can be prevented by using a slight mold-opening or valve-gate delay; direct melt flow into an empty cavity should be avoided. Halo formation around hot drops is associated with local thermal degradation and can be detected as a color shift of ΔE exceeding 2. Such parts should be rejected because the degraded layer reduces weld-line strength and flame retardance.

When specifying FR5260 over glass-filled PC/ABS or die-cast aluminum

Selection of FR5260 instead of a 20% glass-fiber-reinforced PC/ABS FR grade is justified when surface finish, colorability, and notched impact are decisive. The 20% glass-filled grade typically offers flexural modulus above 5000 MPa and HDT above 120°C, whereas FR5260 provides flexural modulus of 2400 MPa and HDT of 95°C. For load-bearing structural ribs or heat-exposed brackets, the glass-filled grade is therefore superior. In exchange, FR5260 avoids glass-fiber surface bloom, has lower melt pressure loss, and allows thinner wall sections down to 1.2 mm with reduced warpage. Compared with die-cast aluminum, FR5260 provides mass reduction of approximately 70%, design integration of snap-fits and wire-routing features, and inherent electrical insulation. However, thermal conductivity is approximately 0.2 W/(m·K), two orders of magnitude below aluminum. Power modules with losses above 5 W require ventilation, metallic thermal inserts, or external heat sinks. Continuous service above 80°C requires thermal aging validation under UL 746B relative thermal index or IEC 60216-1. For applications exposed to glycol-based coolants or hydrocarbon solvents, PC/PBT or PC/PET blends provide better chemical resistance; FR5260 should be screened under ISO 22088-2 with the actual service fluid at the expected applied strain. Ultrasonic insertion of brass inserts into FR5260 is possible at 20 kHz with a 0.3 mm interference; process validation should include pull-out and torque-resistance tests because phosphate flame retardants can affect local friction heating.

Differences from other products in the Dongguan Xinsu Source PC/ABS portfolio are primarily governed by flame-retardant chemistry, melt flow, and impact retention. A higher-flow FR grade may be preferred for multi-cavity tools, while FR5260 targets thicker structural enclosures that require balanced impact. A mineral-filled FR PC/ABS would offer higher modulus but lower spiral flow and lower surface gloss. A brominated FR PC/ABS may offer higher HDT but lower CTI and higher smoke density; the selection of FR5260 for unattended appliance applications is therefore supported by the higher CTI and lower smoke density class of a halogen-free phosphate system.

Thin-wall AC and DC charger housings with nominal wall thickness between 1.2 mm and 1.6 mm are a common application. UL 94 V-0 at 1.5 mm permits the use of these walls without additional flame shields. In unattended appliance applications carrying more than 0.2 A, glow-wire flammability testing per IEC 60695-2-12 is often required; this PC/ABS class typically achieves a glow-wire flammability index of 850°C to 960°C at 1.0 mm, depending on lot and colorant. Comparative tracking index of 600 V per IEC 60112 allows reduced creepage distances for PCB-mounted connectors and busbar supports. For enclosure snap-fits, gate location must be moved away from the retention hook to avoid weld-line fracture; weld-line strength in flame-retardant PC/ABS can be 40% lower than the unfilled base tensile yield. The use of FR5260 in direct contact with lithium-ion cell electrolyte is not recommended; carbonate-based electrolytes cause environmental stress cracking in polycarbonate. A fluoropolymer or polyolefin liner is required.

Flammability classification and electrical tracking behaviour

UL 94 V-0 at 1.5 mm is the primary flame classification. The limiting oxygen index under ISO 4589-2 is generally in the range of 28% to 32%; this value is not a substitute for UL 94 in thin-wall enclosure design. Glow-wire ignition temperature under IEC 60695-2-13 is commonly 775°C to 850°C; the flammability index under IEC 60695-2-12 is often 960°C at 1.0 mm. These values depend on colorant, regrind content, and wall thickness. Under UL 94, V-0 classification at 1.5 mm requires afterflame times not exceeding 10 seconds per flame application and total afterflame time not exceeding 50 seconds for five specimens. Injection-molded parts with different thickness or flow orientation may not retain V-0 if colorant affects flame-retardant dispersion. Surface resistivity under IEC 62631-3-2 is normally above 1 × 10¹⁴ Ω; volume resistivity above 1 × 10¹⁵ Ω·cm. The material is therefore an insulator, not an ESD dissipative material. For ESD-safe housings, a carbon-filled or metal-coated version is required. Dielectric strength under IEC 60243-1 is typically 20 kV/mm to 24 kV/mm at 1.0 mm thickness, but humidity and thermal aging reduce this value; design margins should be at least 50% for reinforced insulation.

The halogen content values in Table 2 apply only to the halogen-free variant; if the FR5260 designation covers both halogenated and halogen-free versions, the lot certificate must state the chemistry. Halogen-free flame-retardant PC/ABS typically uses aryl phosphate, which lowers melt viscosity but can increase moisture uptake and reduce hydrolysis resistance relative to brominated formulations.

Published data for this specific configuration is limited to supplier documentation; the values presented here should be treated as class-typical engineering envelopes. Incoming inspection should verify melt volume-flow rate, moisture content, tensile yield, notched Izod impact at 23°C, and UL 94 V-0 at 1.5 mm for each lot. Injection molding trials on the intended production tool are required before release because additive dispersion, colorant effects, and hot-runner shear history influence final part performance. The material is not recommended for direct food contact, medical device body contact beyond 24 h, or continuous immersion in strong alkaline solutions.