Xiamen Defenghang PC/ABS FR906(NH) is a flame-retardant polycarbonate/acrylonitrile-butadiene-styrene compound in which the FR segment denotes a flame-retardant package, 906 is an internal series code, and NH conventionally denotes a natural-color variant. Under ISO 1043-1:2011, the material belongs to the PC+ABS family and, when marked under ISO 11469:2016, should carry the generic identification >PC+ABS-FR< unless the supplier’s safety data sheet or certificate of analysis specifies a different marking obligation. Because a full supplier datasheet for this exact grade has not been publicly archived at the time of writing, published data for this specific configuration is limited; the property envelope discussed below is therefore benchmarked against standard unfilled flame-retardant PC/ABS grades with comparable density and melt-flow positioning. Exact values require the supplier certificate of analysis. For unfilled flame-retardant PC/ABS in this class, density determined by ISO 1183-1:2019 typically falls between 1.17 g/cm³ and 1.21 g/cm³, while melt volume-flow rate measured by ISO 1133-1:2022 at 260 °C under 5 kg is commonly reported in the range of 15 cm³/10 min to 25 cm³/10 min for medium-flow FR grades. Tensile stress at yield according to ISO 527-2:2012 at 50 mm/min is typically 45 MPa to 60 MPa, and flexural modulus by ISO 178:2019 is typically 2.2 GPa to 2.6 GPa.

Flame-Retardant Performance Is Determined by Char Formation and Wall Thickness

UL 94 classification is not a single material property; it is a thickness-dependent and color-dependent test outcome. The standard vertical burn test uses a 20 mm Tirrill burner with a 50 W methane flame applied twice for 10 s per specimen. For a V-0 rating, the individual afterflame time must not exceed 10 s, the total afterflame time across all flame applications must not exceed 50 s, and no flaming drips may ignite the cotton indicator. A V-0 listing at 3.0 mm therefore does not imply V-0 performance at 1.5 mm or 0.8 mm. Thinner wall sections reduce the available polymer mass for char formation and can increase drip sensitivity. In PC/ABS systems, phosphorus-based flame retardants often operate partly in the condensed phase by accelerating crosslinking and char formation, while brominated systems may operate primarily through gas-phase radical quenching. The FR906(NH) designation alone does not disclose the exact flame-retardant chemistry, and the UL Yellow Card for the grade must be consulted for the certified minimum thickness and color range. Published data for FR906(NH) under glow-wire tests is limited; a UL 94 V-0 classification is not automatically equivalent to compliance with IEC 60695-2-11 glow-wire flammability index or IEC 60695-2-12 glow-wire ignition temperature.

When residual moisture exceeds 0.02 % in the hopper

Pre-drying is the controlling step before injection molding. The material should be dried with dehumidified air at a dew point not higher than −30 °C for 3 h to 4 h at 80 °C; when ambient relative humidity exceeds 60 % or hopper residence time extends beyond 6 h, drying should be extended to 4 h to 6 h. Residual moisture before plastication should remain below 0.02 % by Karl Fischer titration. Higher moisture levels hydrolyze polycarbonate segments, reduce molecular weight, generate silver streaking, and lower notched impact strength. On injection molding equipment, barrel settings should follow a rising profile from rear to nozzle, typically 230 °C to 270 °C, with mold surface temperature held at 60 °C to 80 °C. The screw should use a low compression ratio of 1.8:1 to 2.2:1, and residence time should not exceed 6 min to avoid thermal decomposition of the flame-retardant package. On production-scale hydraulically clamped machines, thin-wall enclosures with wall sections of 1.2 mm to 2.5 mm commonly require clamp force in the range of 5.0 kN/cm² to 7.0 kN/cm² of projected area, depending on flow length ratio. The dominant production-floor failure modes for this class of material are hot-spot decomposition at the check ring, surface splay from moisture, and batch-to-batch color drift in natural grades caused by unstable side-feeder mass flow of the flame-retardant masterbatch during compounding.

How Does FR906(NH) Compare with Glass-Filled and Unfilled PC/ABS Grades?

The primary differences between FR906(NH) and glass-filled flame-retardant PC/ABS grades appear in rigidity, impact response, and flow behavior. At a given wall thickness, unfilled FR PC/ABS grades typically exhibit notched Charpy impact values of 30 kJ/m² to 55 kJ/m² at 23 °C per ISO 179-1:2010, while a 10 wt% glass-fiber reinforced FR PC/ABS may fall to 10 kJ/m² to 25 kJ/m² because the fibers act as stress concentrators during crack initiation. In contrast, the glass-filled variant raises flexural modulus from 2.2–2.6 GPa to approximately 3.5–4.5 GPa by ISO 178:2019. Compared with ABS-FR, PC/ABS FR grades generally show higher Vicat softening temperature by ISO 306:2022 method B50, commonly 95 °C to 115 °C for unfilled flame-retardant PC/ABS, and better low-temperature impact retention. Compared with polycarbonate FR, PC/ABS FR exhibits lower melt viscosity at equivalent melt temperature and can fill thinner walls with lower injection pressure; the trade-off is lower heat deflection temperature under 1.8 MPa.

The table values are literature benchmark ranges for the product class, not certificate values for FR906(NH). A production mold trial with the specified minimum wall thickness is required to confirm actual flow length, weld-line strength, and UL 94 performance.

Electrical and electronic enclosure programs specify natural-color flame-retardant PC/ABS when the part is painted, metallized, or used as an internal bracket where the base tone is acceptable. Target wall thickness is usually between 1.2 mm and 2.5 mm. At these thicknesses, the material must satisfy both the end-product safety standard and molding economics. Thin-wall power adapter housings and electric vehicle supply equipment enclosures often use unfilled FR PC/ABS because they require a balance of impact strength, rigidity, and UL 94 V-0 at the certified minimum thickness. For unattended appliance housings, IEC 60335-1:2020 clause 30.2.3 establishes glow-wire requirements; polycarbonate-rich grades may pass 750 °C or 850 °C hot-wire ignition conditions, but the exact result depends on flame-retardant chemistry and part thickness. Published data for FR906(NH) in specific end-product configurations is limited, so validation on a production mold is necessary. Low-temperature impact down to −20 °C is frequently required for outdoor charger enclosures. In unfilled FR PC/ABS, the ductile-to-brittle transition can occur between −30 °C and −10 °C depending on notch radius and impact speed; higher polycarbonate content shifts this transition to lower temperatures relative to ABS-FR. The natural color designation also avoids pigment-related flame-retardant antagonism sometimes observed with certain heavy-metal pigments.

Flow length and weld-line strength are process-dependent properties that differentiate natural unfilled FR PC/ABS from reinforced alternatives. In thin-wall enclosures, the presence of glass fiber reduces weld-line strength more severely than unfilled PC/ABS because fiber orientation at the meeting front inhibits molecular diffusion across the weld plane. For snap-fit features and living hinges located near weld lines, unfilled FR906(NH) is therefore less vulnerable to brittle failure than a glass-filled grade at the same nominal wall thickness. Mold filling simulation using measured MVR from ISO 1133-1:2022, specific heat capacity, and thermal conductivity should be used to locate gate-induced hesitation marks and pressure drops. On production-scale injection machines, shot-to-shot variation in natural-color FR PC/ABS often becomes visible as gloss variation or streak formation when barrel thermocouple drift exceeds ±5 °C; natural color offers no pigment masking of such surface defects. For this reason, consistent barrel-temperature control and closed-loop cushion stability are more critical for natural FR906(NH) than for black or heavily pigmented FR PC/ABS compounds.

Regulatory Documentation and Supplier-Reported Compliance Limits

Selection of FR906(NH) for electrical, electronic, or industrial housing applications requires documentation beyond the product name. The NH suffix does not independently confirm halogen-free status. If the end-use specification requires halogen-free documentation, the supplier should provide a certificate showing bromine and chlorine below 900 ppm each and total halogens below 1500 ppm when tested according to IEC 61249-2-21. European Union restrictions are defined by Directive 2011/65/EU Annex II as amended by Commission Delegated Directive (EU) 2015/863; supplier declarations are required for the listed substances. REACH Regulation (EC) No 1907/2006 obligations apply when a candidate-list substance exceeds 0.1 wt% in the article. UL certification must appear on a Yellow Card that states the minimum thickness, color range, and applicable UL 94 classification. Marking under ISO 11469:2016 should use the polymer and FR designation supplied by the compounder.

Published data for FR906(NH) under these regulatory modules remains limited to supplier-issued certificates. No compliance assumption should be made from the grade designation alone.