Dongguan Hechuang Plastic ABS 98388 is a styrenic terpolymer of acrylonitrile, butadiene, and styrene supplied in pellet form by Dongguan Hechuang Plastic Materials Co., Ltd. The grade code ABS 98388 is an internal commercial designation; it does not map directly to an ISO designation cell under ISO 2580-1:2019. The material is positioned for injection-moulded rigid components that require a controlled balance of melt flow, notched impact resistance, surface reproduction, and dimensional repeatability. Public access to lot-specific datasheets for this grade is limited; therefore, the property envelope discussed below is derived from class-level ABS moulding-compound data and must be replaced by the supplier’s certificate of analysis before final tooling release.

What Published Property Envelope Governs the 98388 Grade?

Because a single fixed public specification is not supplied for every production lot, the values in the following reference matrix are class-level limits for a medium-impact ABS injection-moulding material. They are not lot-specific guarantees. The batch certificate for the exact shipment should be consulted before quoting mechanical performance for production.

Mechanical testing is normally conducted after conditioning at 23 ± 2 °C and 50 ± 5 % relative humidity in accordance with ISO 291:2008. Under tensile loading, specimen type 1A is elongated at 5 mm/min for yield and 1 mm/min for modulus. The polybutadiene rubber phase controls notched impact; when the temperature approaches the rubber-phase glass transition, impact values drop sharply. Weld-line Charpy notched impact is lower than bulk impact in all injection mouldings; gate placement should be evaluated by short-shot study before production. Published data for the exact weld-line retention factor of ABS 98388 is limited in open repositories. Equivalent tensile data generated under ASTM D638-14 at 50 mm/min may differ from ISO 527-2 values because specimen geometry and elongation rate differ.

Processing Window, Drying Limits, and Machine-Specific Constraints

Pre-drying is mandatory when ambient relative humidity exceeds 60 % or when opened packaging has been stored for more than 4 h. A desiccant dryer with a dew point below -30 °C is set at 80 ± 5 °C for 2–4 h; the target moisture content is 0.03–0.05 % by ISO 15512:2019. Drying above 90 °C or beyond 8 h can cause pellet surface tack and colour shift. If the hopper capacity exceeds actual throughput, residence time should be limited to prevent oxidation.

Representative barrel settings for a reciprocating-screw press with a 20:1 to 24:1 L/D screw are:

• rear zone: 210–220 °C
• middle zone: 230–240 °C
• front zone: 240–250 °C
• nozzle: 240–250 °C

Melt temperature at the nozzle should be held between 230 °C and 250 °C. Residence time above 260 °C must be avoided; polybutadiene phase degradation then produces brown streaking and a fall in notched impact. Total melt residence time should not exceed 5 min at 240 °C. Screw geometry should be low-shear, chrome-plated, and matched to a compression ratio of approximately 2.0:1 to 2.5:1.

Mould temperature is maintained at 40–80 °C. Lower mould temperatures reduce cycle time but increase frozen-in stress and gloss loss; higher mould temperatures improve surface replication and reduce internal strain but extend cooling. For uncoloured parts, excessive shear can cause yellowing; injection pressure is normally set at 80–120 MPa, and holding pressure is 50–70 % of injection pressure for a gate-seal time determined by weighing mouldings in 0.5 s increments.

On production-scale machines with clamp force from 600 kN to 2,500 kN, hot-runner manifolds are operated at 240–250 °C. Internally heated systems with stagnant flow paths are avoided because dead spots generate yellow specks. The non-return valve clearance is maintained for shot-to-shot mass repeatability within ±0.3 %. Regrind is limited to 20–30 % by weight and is dried with virgin pellets; for UL 94-classified parts, virgin resin is preferred unless the regrind source is segregated and validated.

For mould-filling simulation, apparent viscosity at 240 °C and shear rate 1000 s⁻¹ may be represented by a Cross-Arrhenius model fitted to capillary rheometry data from ISO 11443:2021. No grade-specific model constants for ABS 98388 are published in open literature; entering class-level medium-impact ABS constants will give only first-round gate and runner sizing. Pressure-volume-temperature data for packing optimisation should likewise be generated on the actual lot if sink marks are critical. Cavity pressure sensors are typically placed at the gate, mid-cavity, and end-of-fill; a class-level end-of-fill cavity pressure target is 30–50 MPa.

When ABS 98388 Replaces HIPS or High-Flow ABS in Rigid Housings

ABS 98388 is used in injection-moulded enclosures, appliance trims, electronic device housings, automotive interior trim, electrical switch covers, and toy structural parts. In substitution comparisons with HIPS, the primary measured differences are notched impact, tensile yield stress, and softening temperature. ABS 98388 class-level values include Charpy notched impact at 23 °C of 14–30 kJ/m², tensile yield stress of 35–50 MPa, and Vicat B50 of 94–108 °C. HIPS reference compounds typically show Charpy notched impact below 12 kJ/m², tensile yield stress below 28 MPa, and Vicat softening below 90 °C. In aliphatic hydrocarbon wipe-contact service, ABS 98388 shows higher stress-cracking resistance than HIPS; aromatic solvents, ketones, esters, and chlorinated hydrocarbons still attack the styrenic phase.

Compared with high-flow ABS grades having melt volume-flow rate above 30 cm³/10 min, ABS 98388 shifts the property balance toward impact retention and surface quality. Thin-wall sections below 1.0 mm are generally outside the stable processing window at injection pressures of 80–120 MPa; high-flow grades may fill 0.5–0.8 mm walls in the same conditions. The trade-off is impact: high-flow ABS often exhibits lower Charpy notched impact and higher weld-line sensitivity. ABS 98388 is therefore selected when the part carries snap-fits, screw bosses, or visible surfaces requiring stable gloss without painting.

Against high-heat ABS grades with Vicat B50 above 108 °C, ABS 98388 does not extend continuous service temperature under load into the 90–100 °C range. It is not a drop-in for hot-air or under-hood applications. Barrel temperatures are 10–20 °C lower than high-heat ABS, reducing butadiene-phase degradation risk and specific energy consumption.

Against ABS/PC blends, ABS 98388 provides lower low-temperature impact and lower heat resistance. ABS/PC requires desiccant drying at 100–110 °C for 3–4 h; ABS 98388 is dried at 80 °C. In applications where notched Charpy impact at -30 °C must exceed 20 kJ/m², ABS/PC or a high-rubber ABS grade is more appropriate than standard ABS 98388.

Field experience on comparable medium-impact ABS grades indicates that the dominant production defects are silver streaking from moisture, sink marks at thick sections, and jetting at direct gates. Sink marks are controlled by maintaining nominal wall stock at 2.0–2.5 mm, reducing boss diameters, and using holding pressure until gate seal. Jetting is controlled by using a fan or tab gate with land length below 1.0 mm. Screw recovery is set to maintain a melt cushion of 4–8 mm; a cushion below 2 mm gives inconsistent holding pressure, while a cushion above 10 mm increases residence time and risk of butadiene-phase degradation.

Which Regulatory Verifications Accompany Commercial Shipments of ABS 98388?

Compliance documentation for this grade is normally supplied as a batch-specific declaration rather than a universal certification. The following verification matrix lists the applicable frameworks and standard test methods that should be requested from the supplier or a third-party laboratory.

Incompatibility boundaries before tooling release

ABS 98388 should not be mixed with PVC, acetal, or nylon; residual contamination can produce delamination, gas streaks, or catalytic degradation. Contact with aromatic solvents, ketones, esters, and chlorinated hydrocarbons should be avoided because environmental stress cracking can occur under residual mould-in stress. For painted or plated parts, adhesion promoters and etch baths must be qualified on the actual grade; resistance to alkaline cleaners is limited above 50 °C. If a secondary operation requires ultrasonic welding, energy-director geometry and amplitude must be tuned for the butadiene content; published data for this specific configuration is limited, so welding trials on production mouldings are required.