Dongguan Aobang Trading ABS ABS765BK is a black pelletised acrylonitrile-butadiene-styrene terpolymer supplied for injection moulding and selected extrusion work. The trade identifier combines the supplier’s ABS range designation with the suffix BK, which identifies black pigmentation rather than a specific ISO melt-flow cell. Published data for this specific supplier configuration is limited; therefore the following material profile is constructed from the general-purpose ABS property envelope, documented processing practice, and the structural features implied by the grade designation. No numerical value below substitutes for a lot-specific certificate of analysis or a supplier technical data sheet. The base resin is a two-phase thermoplastic composed of a rigid styrene-acrylonitrile copolymer continuous phase and dispersed polybutadiene rubber particles, with the rubber phase commonly present in the range 10 % to 30 % by mass in conventional ABS grades. That biphasic morphology is responsible for the combination of modulus, surface hardness, and notched impact resistance that distinguishes ABS from single-phase styrene-based resins such as polystyrene or general-purpose SAN.

The model-specific designation ABS765BK does not correspond to a published ISO designation block. Under ISO 2580-1:2013, an ABS moulding material is fully specified by a series of cells covering heat deflection temperature, melt mass-flow rate, Izod impact strength, and Vicat softening temperature. The supplier code 765 is a proprietary ordering sequence and not an encoded property cell. For production verification, a received pellet lot should be checked against the supplier certificate for melt volume-flow rate measured at 220 °C and 10 kg according to ISO 1133-1:2022, density according to ISO 1183-1:2019, and tensile properties according to ISO 527-2:2012.

Which Property Envelope Governs a Black-Coloured General-Purpose ABS Compound?

General-purpose black ABS grades of this class typically fall within the property range summarised in Table 1. The data are compiled from commercial ABS technical bulletins and are presented as a screening envelope, not a guaranteed product specification. For moulding trials, the following material parameters must be confirmed before tooling transfer, because carbon black dispersion and rubber-phase morphology can move a supplied lot within or outside the envelope.

The tinctorial strength of the black carbon-black dispersion can alter melt viscosity by a small but measurable amount relative to the unpigmented base. A lot-specific melt volume-flow rate should therefore be used for gate freeze time and injection pressure calculations. The property window in Table 1 is not a material certification and does not replace first-article part testing.

Colourant Dispersion, Carbon Black, and BK Suffix

The principal difference between ABS765BK and a natural or tinted ABS of the same base polymer is the presence of carbon black introduced during compounding. The BK colourant state removes the need to meter a separate black masterbatch at the press, reducing the risk of dose-weighing error on multicomponent blending lines and avoiding the surface streaking that can occur when masterbatch dispersion is incomplete. Carbon black in a well-dispersed ABS compound should show sub-micrometre particle agglomerates in a polished plaque; poor dispersion appears as brown-grey streaks on thin-walled bosses and is not corrected by increasing barrel temperature alone. Because the supplier’s compounding method is not stated in the accessed trade data, incoming lots must be examined by pressure filter test, polished-plaque gloss, or injection-moulded chip inspection before release to production. A surface gloss value above 80 GU at 60° measured according to ISO 2813:2014 or ASTM D2457-21 can serve as a screening criterion for dispersion consistency, but the numerical target is part-tool dependent.

In terms of optical function, ABS765BK typically provides lower reflected light values and greater opacity at wall thicknesses below 1 mm than a natural ABS. This optical behaviour is relevant for light-blocking housings, sensor bezels, and internal baffles where ambient light must not reach a detector window. The black colourant system may also reduce visible yellowing from thermal ageing compared with unpigmented ABS, but that does not imply elevated heat-deflection performance.

Injection moulding of ABS765BK on a production-scale reciprocating-screw machine of 800 kN to 1300 kN clamp force requires pre-drying at 80 °C to 90 °C for 2 h to 4 h in a desiccant dryer with a dew point of −30 °C or lower. The residual moisture target before plastication is 0.05 % by mass or lower. Moisture above approximately 0.08 % in the melt can produce splay, silver streaking, and surface defects that are especially visible on black glossy substrates. A general-purpose or reverse-taper screw with an L/D ratio of 18:1 to 22:1 and a compression ratio of 2.0:1 to 2.5:1 is sufficient for single-stage plastication. Barrel zone settings typically ramp from 210 °C to 240 °C from feed throat to nozzle, with nozzle temperature held at 230 °C to 250 °C. Mould surface temperature should remain between 40 °C and 80 °C. Lower mould temperatures reduce cycle time but can decrease knit-line impact strength in multi-gate tools and increase moulded-in stress. Injection velocity and hold pressure must be tuned to avoid jetting, gas traps, and burn marks. Aggressive ejection at sharp corners can induce white stress-blanching on black ABS, even when the bulk part is within dimensional tolerance.

When the Grade Must Replace HIPS Without a Separate Black Masterbatch Addition

A substitution analysis for replacing black high-impact polystyrene with ABS765BK begins with the difference in stress crack resistance and surface scratch resistance, balanced against higher melt viscosity and higher processing temperature. HIPS typically exhibits tensile yield stress near 20 MPa to 30 MPa, while ABS grades of the ABS765BK class commonly show tensile yield stress above 35 MPa. Notched Izod impact strength for ABS is generally reported in the range 15 kJ/m² to 30 kJ/m² at 23 °C. The substitution is not drop-in. Gate and runner sizing may need to increase because the linear melt viscosity of ABS at 220 °C can be higher than HIPS at the same temperature, and the ABS melt is more sensitive to excessive shear heating. Unlike polycarbonate/ABS blends, the ABS765BK matrix contains no polycarbonate segment. Prolonged contact with concentrated ketones, esters, or aromatic hydrocarbons should therefore be evaluated by ISO 22088-3 or ASTM D543-21 immersion testing, because environmental stress cracking resistance is part-specific and strongly influenced by residual moulded-in stress. Compared with a black PC/ABS, ABS765BK generally has lower heat distortion and lower notched impact at sub-zero temperatures, but it can be processed at lower melt temperature and typically develops less shear heating during high-velocity injection.

Rear housing for benchtop diagnostic instruments, vacuum cleaner bodies, and automotive interior trim panels are representative application categories in which the BK designation is relevant. In instrument housings, the material should be screened for resistance to quaternary ammonium disinfectants and isopropyl alcohol at 70 % concentration under ASTM D543-21 or ISO 2812-1:2017. Stress-cracking failures are a function of chemical exposure time, temperature, part geometry, and moulded-in stress, not colourant alone. For automotive interior trim, migration resistance and fogging behaviour are evaluated by ISO 6452 or SAE J1756, and low-temperature impact of a grained black surface may be checked by ISO 6603-2 at −20 °C. Published data for ABS765BK specifically in UL Recognized Component scenarios is limited; a yellow card is not to be inferred from generic ABS listings. Where a regulated electrical enclosure requires a defined glow-wire result, the moulder must obtain the supplier’s IEC 60695-2-11 test report or equivalent lot-specific evidence. RoHS status should be verified against Directive 2011/65/EU Annex II and its delegated amendments, and REACH Article 33 obligations should be resolved through a full material declaration rather than a generic statement.

Extrusion of ABS765BK sheet or profile is possible when the lot-specific melt volume-flow rate is suitable. Drying becomes more critical because sheet surface area amplifies the visual impact of moisture splay and black sheet reveals silver streaks readily. A single-screw extruder with 20:1 to 30:1 L/D and a breaker plate with a 120 mesh screen pack is typical for thin-gauge black ABS sheet, but published data for this specific supplier configuration is limited. Barrel temperature, screw cooling, and roll stack temperature must be established from a process capability study on the actual line.