Qingdao Haier New Material supplies PC/ABS NH-9012 as a non-halogen flame-retardant polycarbonate/acrylonitrile-butadiene-styrene alloy in pellet form for injection moulding. The grade is intended for appliance enclosures, power-supply housings, and electronic data terminals where UL 94 V-0 at 1.5 mm is specified. The NH designation indicates that the flame-retardant package contains no intentionally added brominated diphenyl ethers or polybrominated biphenyls; performance relies on a phosphorus-based char-forming system in the polycarbonate-rich phase. This composition distinguishes NH-9012 from halogenated PC/ABS grades that achieve thin-wall flammability through bromine-containing additives and from unfilled general-purpose PC/ABS grades that lack the same flame-retardancy classification.

Supplier technical data for NH-9012 are summarized in Table 1. Values are representative lot data, not guaranteed specification minima. For end-product qualification, Qingdao Haier New Material should provide the current lot-specific certificate of analysis.

Mechanical test specimens are conditioned at 23 °C and 50% relative humidity per ISO 291:2008. Tensile properties are determined on type 1A specimens per ISO 527-2:2012 at a test speed of 50 mm/min; flexural modulus is measured at 2 mm/min per ISO 178:2019. Charpy notched impact energy is reported from edgewise impact per ISO 179-1/1eA:2023 using a 2 mm notch radius. Heat deflection temperature under 1.8 MPa is measured on flatwise specimens. These test conditions should not be transposed to service performance without part-level validation.

Mould shrinkage data are relevant for tool layout. The range of 0.4% to 0.7% varies with gate type, wall thickness, packing pressure, and flow orientation. For a rectangular edge-gated plaque of 2.0 mm wall thickness, flow-direction shrinkage is typically at the lower end and transverse shrinkage at the upper end. In production tools with hot runner systems and multiple gates, differential shrinkage is a primary cause of warpage; cooling channel layout and gate position should be optimized by mould-filling simulation using pressure-volume-temperature data for NH-9012 rather than generic PC/ABS data.

Applications reported for NH-9012 include washing machine control panel frames, air conditioner air guide housings, refrigerator display bezels, and small appliance power-supply shells. The grade is selected where enclosure parts require glow-wire ignition resistance at 850 °C per IEC 60695-2-11:2021. Compliance with IEC 60335-1:2020 clause 30.2 for unattended appliances should be verified on the finished part because glow-wire results depend on wall thickness, distance from live parts, and boss geometry. Published data for this specific configuration is limited; the material supplier does not provide blanket end-product certification.

Why does residual moisture above 0.02% produce silver streaking and impact loss?

The polycarbonate component of NH-9012 hydrolyzes at melt temperatures when moisture content exceeds 0.02%. Hydrolysis reduces molecular weight and produces carbon dioxide and bisphenol A degradation products, which appear as silver streak or splay at the flow front. In production-scale processing, parts moulded from material exposed to ambient air at 55% relative humidity without drying showed notched Charpy impact values falling from 35 kJ/m² to below 18 kJ/m² within 2 h of hopper residence. A desiccant dryer with a dew point no higher than -30 °C and a closed-loop hopper is required. Drying at 80 °C to 90 °C for 3 h to 4 h reduces moisture below the threshold; at relative humidity above 60%, the minimum drying time should be extended to 4 h. Moisture content should be verified by Karl Fischer titration according to ISO 15512:2019 before start-up.

On a production injection moulding machine with a 650 t clamp force, 120 mm screw diameter, and 24:1 L/D ratio, the following parameters are typical for parts with wall sections between 2.0 mm and 3.5 mm: melt temperature 245 °C to 260 °C, mould temperature 60 °C to 80 °C, injection pressure 80 MPa to 120 MPa, holding pressure 50% to 70% of injection pressure, and back pressure 0.3 MPa to 0.7 MPa. Screw peripheral speed should be kept between 0.2 m/s and 0.4 m/s; excessive screw speed introduces frictional heat and dark streaks. Cushion position should be held at 3 mm to 5 mm; failure to maintain cushion reduces holding pressure transfer and increases sink mark and warpage in thick sections.

Production trials with NH-9012 show that weld line strength in flame-retardant PC/ABS is lower than in unfilled general-purpose grades. When weld lines are unavoidable, gate location should be selected so the weld line forms in a low-stress area. The melt front temperature at the weld line should not fall below 230 °C; lower temperatures produce visible notched weld lines and reduce impact strength by more than 30% compared with non-weld material. Venting depths of 0.02 mm to 0.03 mm on the parting line are generally sufficient for trapped gas removal without flash.

Non-Halogen Flame Retardancy and Thermal Decomposition Boundary

The non-halogen package in NH-9012 functions primarily through intumescent phosphorus-based char formation in the condensed phase. Under thermal stress, the additive promotes crosslinking of the polycarbonate-rich surface, reducing heat release and mass loss. Thermogravimetric analysis according to ISO 11358-1:2022 typically records onset of decomposition near 385 °C under nitrogen, with a major degradation step between 400 °C and 520 °C. This places NH-9012 below general-purpose polycarbonate in decomposition onset but above brominated PC/ABS grades that release acidic decomposition species. In vertical flame testing per IEC 60695-11-10:2013, the grade achieves UL 94 V-0 at 1.5 mm and 3.0 mm, with afterflame times typically under 5 s per specimen.

Smoke density measured according to ISO 5659-2:2017 at 25 kW/m² is lower than for brominated equivalents. Published data for this specific configuration is limited, but comparative studies on non-halogen phosphorus flame-retardant PC/ABS systems report reductions in peak specific optical density of 20% to 40% relative to brominated counterparts. This is relevant for enclosed electrical compartments where smoke opacity affects occupant egress or service personnel visibility.

The processing thermal boundary is more restrictive than that of general-purpose PC/ABS. Residence time at melt temperature should not exceed 8 min at 250 °C. At 270 °C, maximum residence time should be reduced to 5 min; beyond these limits, the material yellows and Charpy notched impact values decline due to polycarbonate chain scission and degradation of the non-halogen flame-retardant package. In hot runner systems, dead spots and undersized gates cause local residence times above these limits; flow channels should be designed with full-round or trapezoidal cross-sections and no blind pockets. When production interruptions exceed 10 min, the barrel should be purged with virgin PC/ABS or polycarbonate melt at 250 °C.

When regrind ratios exceed 20%, mechanical property drift and surface defects are observed

Ground sprue and runner material can be reintroduced into the feed stream at up to 20 wt%. Field data from a washing machine control panel production line indicate that regrind at 20% reduces Charpy notched impact strength by 8% to 12% compared with virgin material. At 30% regrind, the material exhibits visible silver streaks and lower melt viscosity, increasing short shot frequency. Regrind particles should be uniform, free of fines below 2 mm, and passed through a metal separator to protect the screw and check ring. Drying of regrind is required at the same conditions as virgin material because regrind absorbs moisture more rapidly due to high surface area. Recycled material from painted or coated parts should not be used without detailed contamination analysis; paint particles can block venting and create delamination.

Compared with a typical brominated flame-retardant PC/ABS, NH-9012 avoids halogen acids in combustion and is more suitable for electrical enclosures where low smoke acidity is specified for evacuation environments. A brominated grade may achieve UL 94 V-0 at 0.8 mm; NH-9012 is specified at 1.5 mm, so wall thickness reductions below 1.5 mm require qualification on the actual part geometry per UL 746C or the relevant end-product standard. The denser char of the non-halogen system can also increase mould deposit formation at high melt temperatures; mould surfaces should be cleaned after every 20,000 to 30,000 cycles to prevent gas stains and vent blockage.

Against general-purpose unfilled PC/ABS, NH-9012 has lower melt flow. The MVR of NH-9012 at 260 °C/5 kg is approximately 18 cm³/10 min, while high-flow unfilled PC/ABS grades may reach 30 cm³/10 min to 45 cm³/10 min; this difference requires larger gates or higher melt temperature in thin-wall tools. However, NH-9012 provides inherent flame retardance without secondary halogenated additives and meets the same UL 94 V-0 rating at 1.5 mm. Compared with mineral-filled PC/ABS, NH-9012 has lower flexural modulus, typically 2400 MPa versus 3200 MPa to 4500 MPa for mineral-filled grades. It should not be substituted into load-bearing brackets where creep resistance or stiffness dominates design.

Chemical resistance is governed by the ABS phase. Contact with ketones, esters, aromatic hydrocarbons, and strong acids should be avoided unless parts are annealed and tested. For external enclosures, a compatibility test with common skin oils and commercial cleaning agents is advised. Stress cracking tests per ISO 22088-2:2006 may be used for screening. The use of amine-containing mould releases or polyurethane paint solvents should be avoided because of polycarbonate degradation and stress cracking.

NH-9012 is formulated for RoHS 2011/65/EU, but the final article must be assessed at the homogeneous material level. Supplier declarations generally list lead, mercury, hexavalent chromium, PBB, and PBDE below 1000 ppm, and cadmium below 100 ppm. REACH Regulation EC 1907/2006 SVHC screening is required per Article 33; the supplier should provide an SVHC statement for the specific production lot. The material is not self-declared as food-contact grade; applications requiring FDA 21 CFR or EU 10/2011 compliance require separate migration testing on the finished article.

Surface quality from polished moulds is high, but the non-halogen flame retardant can produce jetting if gate velocity is excessive. Gate land length should be 1.0 mm to 2.0 mm for wall thicknesses below 3 mm; use of a full-round runner with diameter 6 mm to 8 mm assists pressure transmission. Mould temperatures below 60 °C reduce gloss and can induce delamination at the gate. Higher mould temperatures near 80 °C improve knit line appearance but extend cooling time by 10% to 15%.

On a production line for air conditioner air guide housings moulded from NH-9012, switching from a mineral-filled PC/ABS to NH-9012 increased melt flow length and reduced part weight by approximately 6% because of lower density, but the tool’s rib thickness had to be increased from 1.0 mm to 1.2 mm to maintain flame retardancy and stiffness.