Kumho Petrochemical ABS SDP-0150 is classified as a high-flow acrylonitrile-butadiene-styrene injection-moulding resin within the Starex ABS product line. The grade is formulated to shift the conventional ABS property balance toward shorter cycle times and larger flow-length-to-wall-thickness ratios in rigid consumer electronics and appliance housings. Melt flow index measured under ISO 1133-1:2022 at 220 °C and 10 kg is reported as 15 g/10 min, placing it at the upper end of medium-flow ABS and at the lower end of super-high-flow ABS. The polymer consists of a styrene-acrylonitrile copolymer continuous phase and a discrete polybutadiene rubber phase, with rubber content held in the range 10–15 wt% to maintain stiffness and surface hardness while providing sufficient notched impact resistance for snap-fit and screw-boss features. The material is supplied in pellet form for reciprocating-screw injection moulding and is not intended for extrusion sheet or profile applications.

How Does SDP-0150 Differ from General-Purpose and Heat-Resistant Starex ABS Grades?

Selection between SDP-0150 and a general-purpose Starex ABS such as 750 is determined by minimum wall thickness and available clamp force. SDP-0150 has a higher melt flow index than common general-purpose grades; where SDP-0150 is reported at 15 g/10 min, general-purpose moulding grades often occupy the range 4–8 g/10 min under ISO 1133-1:2022 at 220 °C and 10 kg. This difference reduces cavity filling pressure and enables thinner nominal wall sections, but the advantage is specific. In sections greater than 3.0 mm, the lower melt viscosity of SDP-0150 increases the risk of jetting and weld-line formation unless gate location, gate diameter, and venting are adjusted accordingly. Compared with high-impact grades such as Starex HI-121H, SDP-0150 exhibits lower polybutadiene content and a smaller rubber particle size distribution, which reduces notched Izod impact but improves melt flow and surface gloss. Compared with heat-resistant Starex HR-0370, SDP-0150 has a lower Vicat softening temperature by approximately 10 °C; it is not specified for continuous service above 85 °C in load-bearing under-hood or heat-generating appliance applications. Direct substitution into a mould designed for high-impact or heat-resistant ABS should be preceded by part-level impact and heat-ageing evaluation because the high-flow balance modifies failure modes at weld lines, screw bosses, and snap-fit arms.

Pre-drying is mandatory above 60% ambient relative humidity. ABS pellets absorb atmospheric moisture rapidly; unconditioned resin can exceed 0.35 wt% moisture within 2 h at 25 °C and 80% relative humidity. Desiccant drying at 80 °C for 3–4 h with a dew point of −30 °C or lower reduces pellet moisture below 0.02 wt% as measured by ISO 15512:2019 method A. In moulding trials on a 120 tf hydraulic injection moulding machine with a 25 mm screw and 20:1 L/D, insufficient drying produced splay on the surface of a 1.2 mm wall housing and reduced notched impact strength by approximately 25% relative to dry pellets. Barrel settings from rear to nozzle are commonly set at 190 °C, 200 °C, 210 °C, 220 °C, and 215 °C, while mould temperature is maintained between 30 °C and 55 °C. At mould temperatures above 60 °C, cooling time increases and gate blush may become visible on high-gloss surfaces; below 30 °C, knit-line strength declines in thin ribs and bosses. Moisture-related defects are not eliminated by raising barrel temperature alone because hydrolytic degradation of the polybutadiene phase occurs during melt residence.

Melt Rheology and Thin-Wall Filling Behaviour

At the reported melt flow index of 15 g/10 min, SDP-0150 exhibits shear-thinning behaviour typical of high-flow ABS. Its lower melt viscosity reduces injection pressure under thin-wall flow conditions, but the trade-off is lower melt strength during free-surface flow. The material is suitable for thin-wall injection-moulded parts such as power adapter housings, display bezels, and small appliance shells where nominal wall thickness is between 1.0 mm and 2.5 mm. In spiral-flow evaluations typical of ABS compounds, a high-flow grade in this melt index class can fill a spiral thickness of 1.0 mm to a flow length beyond 120 mm when peak injection pressure is held near 70 MPa and the gate is a 0.8 mm side-edge or fan gate. Published data for this specific configuration is limited, and the flow length should be confirmed using the production tool and injection profile. The material is not suitable for extrusion sheet or profile because low melt strength leads to sag in thick calendered sheet; extrusion-grade ABS requires lower melt flow index and higher molecular weight in the styrene-acrylonitrile phase. Hot-runner tip temperatures above 250 °C can thermally degrade residual butadiene and produce an acetaldehyde-like odour, so direct-gated parts should maintain nozzle temperatures below 230 °C.

SDP-0150 is specified for snap-fit and screw-boss features only after notched Izod sensitivity is evaluated at the minimum service temperature. Notched Izod impact strength measured under ISO 180:2019 method 1A at 23 °C is 20 kJ/m²; at −30 °C the value declines to 7 kJ/m². Designers using the material in cold climates should avoid sharp internal corners below 0.5 mm radius and should not specify integral live hinges, because the polybutadiene phase does not provide polyolefin-like flexural fatigue resistance. Tensile stress at yield under ISO 527-2:2012 is approximately 44 MPa, flexural modulus under ISO 178:2019 is approximately 2300 MPa, and flexural strength is approximately 65 MPa. The combination is adequate for rigid enclosures but not for structural brackets, load-bearing gears, or high-energy impact applications. In multi-cavity tools, peak injection pressure and hold pressure should be profiled independently for thin bosses and thick gate regions to prevent local overpacking; overpacking produces stress whitening around the gate and increases ejection force. Shrinkage behaviour follows amorphous styrenic tendencies, with mould shrinkage typically in the range 0.4–0.6% in the flow direction and 0.5–0.7% transverse to flow, though part geometry and mould temperature shift these values.

When SDP-0150 Is Substituted into Thin-Wall Electronic Housings

In a direct substitution from general-purpose ABS, screw recovery time is reduced because of lower melt viscosity. The cushion position is held between 2 mm and 4 mm to avoid over-shearing the rubber phase. Excessive hold pressure above 50 MPa can produce gate-area stress whitening; insufficient hold pressure below 25 MPa increases sink marks over ribs and bosses. Dimensional stability is improved by adding a 0.5 s screw delay after injection and maintaining uniform mould temperature across the cavity. If mould temperature differential exceeds 10 °C, warpage in a 1.2 mm enclosure side wall is observed due to differential shrinkage. The ejection system must accommodate a draft angle of at least 0.5°; at lower draft, ejection stress can induce microcracks around the ejector pin. Weld lines in thin-wall bosses are a known failure site because the high-flow grade has lower melt strength and less rubber-phase bridging at the flow front compared with high-impact ABS. Vacuum venting or gas-vent pins may be required to prevent burning in blind ribs and deep bosses. For bright or high-gloss surfaces, mould surface replication is highly dependent on mould temperature; a mould temperature of 40 °C to 55 °C is commonly maintained to balance gloss, cycle time, and ejection stability. Below 30 °C, surface gloss decreases and the visibility of weld lines increases.

Electrical and electronics applications of SDP-0150 are supported by a flammability classification of HB at 1.6 mm thickness under UL 94. The grade is not flame-retarded and is not a candidate for enclosures requiring V-2, V-1, or V-0 ratings without a flame-retardant additive package or specification change to a flame-retardant Starex ABS grade. Heavy metal content is controlled under RoHS 2011/65/EU recast Annex II, and a REACH SVHC declaration is typically available from the manufacturer. For food-contact applications, compliance under EU 10/2011 or FDA 21 CFR 175.300 must be confirmed for the specific formulation and colour because published data for this specific configuration is limited. The material is not recommended for outdoor UV exposure; sustained UV weathering without protective coating or carbon black causes surface chalking and impact loss due to polybutadiene oxidation. UV-stabilized ABS grades should be specified for outdoor enclosures. Surface painting, metallization, or adhesive bonding should be validated on moulded plaques because mould release migration and low-molecular-weight styrene-acrylonitrile oligomers can reduce adhesion. Plasma or corona pretreatment may be required before polyurethane coating or solvent bonding.

The Published Property Set Is Defined by ISO 527-2 and ISO 180 Method 1A

The following values are representative of manufacturer-published data for Kumho Petrochemical Starex ABS SDP-0150. Users should verify against the current certificate of analysis for the specific production lot because slight shifts occur with colour concentrates and regrind addition.

Incoming quality control should verify melt flow index and moisture content before release to production. A single-point viscosity check at 220 °C and 10 kg is insufficient for detecting lot-to-lot rubber-phase variation; melt flow index should be accompanied by notched Izod and Vicat softening measurements on each silo or batch. If lot-to-lot melt flow index variation exceeds ±2 g/10 min, moulding parameters must be adjusted or the lot quarantined. Rubber-phase particle size distribution is not measured in routine incoming quality control but is controlled by the manufacturer through polymerization and melt compounding conditions. Published data for particle size distribution of SDP-0150 is limited; scanning electron microscopy of ultra-thin sections shows a dispersed rubber morphology with weight-average particle size typically below 1 µm.

Design of gate and runner systems for SDP-0150 must account for high shear and short residence time. Combination with amine-based mould-release sprays is not recommended because amine compounds can accelerate hydrolysis of the styrene-acrylonitrile phase and cause surface haze. If external release agent is required, a hydrocarbon-free, silicone-free mould release formulated for styrenic thermoplastics should be used. Regrind addition is acceptable up to 20 wt% in non-appearance parts, provided the regrind has been dried and is free from dust and mixed-colour contamination; higher regrind increases variability in melt flow index and dark speck formation. Injection moulding operators should monitor melt residence time because the high-flow grade has a narrower thermal degradation threshold in hot-runner systems than higher-viscosity general-purpose ABS. The melt should not remain above 220 °C for more than 10 min during production interruptions; if longer residence is required, barrel temperature should be reduced to 160 °C or the melt should be purged before restart.