Xiamen Defenghang ABS L218(D) is an acrylonitrile-butadiene-styrene copolymer grade supplied by Xiamen Defenghang Plastics Co., Ltd., assigned to the manufacturer’s L-series. The material is positioned for injection moulding and profile/sheet extrusion in which a middle-range melt viscosity, controlled surface quality, and practical impact resistance are required. The (D) suffix differentiates this formulation from the unmodified L218 base by a proprietary adjustment to the heat-stabilizer and external lubricant package; the exact additive composition is not disclosed in the general technical literature, so lot-specific certificates of analysis remain the controlling document for production release. Published data for this specific configuration is limited, and the following technical envelope therefore describes the class behavior expected of the grade while identifying the validation steps required before substitution from another ABS source. Classification and specimen preparation are governed by ISO 2580-1 and ISO 2580-2, with mechanical property determinations performed under ISO 527-2, ISO 179-1, and ISO 75-2 where applicable.

What Published Property Data Define the L218(D) Performance Envelope?

The property range associated with this grade is best interpreted as a design and incoming-inspection envelope rather than a fixed guarantee. Because lot-to-lot variation in emulsion-polymerized polybutadiene content and SAN molecular weight distribution affects stiffness, melt viscosity, and impact strength, the values in Table 1 are class-typical ranges that must be verified against the supplier’s certificate of analysis for each shipment. Tensile values referenced to ISO 527-2:2012 are not directly interchangeable with data generated under ASTM D638-14 Type I specimens because of differences in specimen thickness and gauge geometry. Notched impact values should be interpreted with attention to the exact notch radius and conditioning procedure; ISO 179-1/1eA:2023 and ISO 180/A cannot be treated as equivalent without an experimentally established correlation for this specific ABS grade.

Table 1. Class-typical property envelope for Xiamen Defenghang ABS L218(D); values are not lot-specific release limits.

Processing-related data for this grade must be developed on the intended production machine. The melt volume-flow rate band of 8–20 cm³/10 min at 220 °C under 10 kg load indicates a medium-flow ABS that can fill moderate flow paths but is not optimized for extreme thin-wall tools. Regulatory compliance with EU 2011/65/EU Annex II and REACH 1907/2006 Article 33 should be confirmed through lot-specific supplier documentation rather than assumed from the generic grade description.

Drying before processing is not optional for this ABS class. Moisture content above 0.03–0.05% by weight can produce silver streaking, splay, and loss of surface hardness through stabilizer hydrolysis. Desiccant drying at 80–85 °C for 2–4 h with a dew point of −20 °C or lower is acceptable when material is transferred directly from sealed bags to the drying hopper; if ambient storage relative humidity exceeds 60%, drying time should be extended to 4–6 h. In injection moulding, the melt temperature should be profiled from rear zone to nozzle between 210 °C and 250 °C, with a preferred nozzle setpoint near 230 °C. Sustained melt temperatures near 260 °C initiate thermal degradation of the styrene-acrylonitrile phase and crosslinking of the polybutadiene rubber, resulting in yellowing and a drop in Charpy impact strength. Mould surface temperatures from 30 °C to 70 °C are acceptable, but the upper half of this band is preferred for thin-wall structural parts because higher mould temperature improves weld-line strength and reduces frozen-in orientation. General-purpose screws with an L/D ratio of 20:1 to 24:1 and a compression ratio of 2.5:1 to 3.0:1 are suitable. Peak injection pressures in direct spruce-fed tools commonly fall between 70 MPa and 120 MPa; hold pressure should be 40–60% of peak hydraulic pressure, with gate-freeze time determined from cavity pressure sensors rather than fixed timer settings. Back pressure should remain low, in the 0.3–0.7 MPa band, to limit frictional heating. For sheet or profile extrusion, a barrel temperature profile from 180 °C to 220 °C and a die temperature of 200–230 °C are typical; screen packs of 60/80/100 mesh are used to generate head pressure and remove foreign particles, but the resulting pressure must stay below the extruder manufacturer’s maximum rating. Melt residence time above 240 °C should be minimized because prolonged exposure degrades the butadiene phase and shifts final part colour toward yellow.

Comparative Property Positioning of L218(D) Against High-Flow and High-Impact ABS

The primary difference between L218(D) and high-flow ABS grades is the melt viscosity. High-flow grades in the same supplier family may exhibit melt volume-flow rates from 25 cm³/10 min to 40 cm³/10 min, whereas L218(D) occupies the 8–20 cm³/10 min band. This lower flow makes L218(D) less suitable for thin-wall housings with flow-length-to-wall-thickness ratios above 150:1, but it provides better retention of notched impact strength in snap-fit features and reduces the incidence of ejection cracks. Compared with high-impact ABS, L218(D) deliberately accepts a lower room-temperature Charpy notched impact ceiling in exchange for higher tensile modulus and better heat deflection stability under load. Flame-retardant ABS grades are a separate product class; they contain brominated or phosphorus-based packages that reduce melt stability and increase plate-out tendency. L218(D) does not contain a flame-retardant package and is not a replacement for UL 94 V-0 electrical enclosure materials unless the part design includes shielding, coating, or another flame-barrier strategy. The (D) suffix differentiates the material from the base L218 by the addition of a lubricant package intended to reduce deposit accumulation on polished tool surfaces and vacuum calibrators. This benefit is most apparent in continuous extrusion runs longer than 8 h, where lower plate-out reduces cleaning frequency. Because external lubricants can lower surface energy, paint adhesion, printing durability, and electroplating adhesion should be revalidated after a substitution involving this grade.

Table 2. Qualitative and quantitative positioning of L218(D) against adjacent ABS classes; exact lot data are required for tool release.

The comparative data indicate that L218(D) is selected when a single material must perform consistently across both injection moulding and extrusion lines without the high-flow penalty on impact resistance or the high-impact penalty on heat resistance. The grade is not intended to replace high-impact ABS for luggage shells, helmets, or low-temperature impact parts where notched impact values above 35 kJ/m² are mandatory.

Applications for L218(D) concentrate in moulded and extruded goods requiring a controlled combination of melt processability, dimensional stability, and surface consistency without demanding extreme low-temperature ductility. Typical production-scale examples include vacuum cleaner housings with nominal wall thickness of 2.2–3.0 mm, appliance control-panel surrounds that must retain dimensional fitment after post-moulding conditioning, furniture edge-banding profiles produced through vacuum calibration, and coextruded ABS trim layers where low plate-out is economically significant. In these applications, moulding shrinkage measured according to ISO 294-4:2018 generally falls between 0.4% and 0.7%, but anisotropic shrinkage in unreinforced ABS requires gate-location-specific compensation. The grade is not approved for electroplating or high-adhesion painting without surface-energy validation because the external lubricant package can alter wetting; adhesion tests under ISO 2409 or ASTM D3359 should be performed on moulded plaques before production release. Unfilled ABS of this class is limited to indoor applications unless UV-stabilized or covered by a coextruded cap layer. Any specification requiring UL 94 V-0 or IEC 60695-11-10 flammability classification cannot be satisfied by L218(D) as an unfilled non-flame-retardant grade; the part design would require a flame barrier, metal housing, or a different material from the manufacturer’s portfolio.

When L218(D) Is Substituted into Existing ABS Tools Without Melt Temperature Adjustments

Substitution of L218(D) into a tool originally qualified with a lower-viscosity ABS produces a characteristic failure pattern if melt temperature and injection speed remain unchanged. Short shots appear first in ribs, bosses, and living hinges where flow-length-to-wall-thickness ratios exceed 120:1; the flow front freezes prematurely, and cavity pressure at end of fill may fall below 35 MPa. The resulting parts exhibit elevated orientation-induced stress, and post-moulding shrinkage can increase by 0.1–0.3 percentage points relative to the original grade. Compensation should begin by raising the nozzle temperature in 5 °C increments within the 210–250 °C processing window while monitoring melt pressure at the nozzle. If the press is equipped with cavity pressure transducers, switch-over should be adjusted to maintain peak cavity pressure between 40 MPa and 70 MPa. When shear heating is insufficient, injection speed should be changed from a single-stage fill profile to a two-stage profile: a fast first stage to fill the runner and gate, followed by a slower second stage to prevent jetting. Maximum shear rate at the gate should remain below 10,000 s⁻¹ to limit rubber-phase degradation. In sequential valve-gated tools, valve delays may need to be increased by 0.2–0.5 s because the lower melt-front velocity of L218(D) alters cavity filling sequence. In extrusion substitution, die pressure commonly rises and output may fall if screw speed is unchanged; a screw with 30:1 L/D and a Maddock mixing section is less sensitive to the viscosity shift than a standard metering screw. Melt temperature should be checked with an immersion thermocouple at the adapter, and barrel heater setpoints should be adjusted to keep the melt within the allowed range without exceeding 240 °C. Failure to observe these limits produces surface defects, gauge instability in calibration, and dimensional drift in downstream forming.