Jiangsu Xinfuda supplies the acrylonitrile-butadiene-styrene injection moulding grade Hepla H1100 HG T as a high-gloss, toughened styrenic formulation for appearance-critical thin-wall mouldings. The HG T suffix is consistent with high-gloss and toughened performance, but lot-specific values must be obtained from the supplier’s certificate of analysis. Published independent data for this exact configuration are limited; numerical ranges in this document therefore classify the material as a high-gloss toughened ABS rather than a certified lot-specific result. Acrylonitrile-butadiene-styrene consists of a continuous styrene-acrylonitrile matrix with a dispersed polybutadiene rubber phase. Rubber particle size distribution and graft morphology govern the balance between specular gloss, melt flow, and impact energy absorption. In a high-gloss toughened grade, a controlled fine rubber fraction maintains 60° specular gloss above 90 GU (ISO 2813) while retaining notched Izod impact at 23 °C in the range 18–35 kJ/m² (ISO 180/A).

For production specification, the supplier’s technical datasheet should be checked for density (ISO 1183-1:2019), melt volume-flow rate (ISO 1133-1:2022, 220 °C/10 kg), tensile yield stress (ISO 527-2), flexural modulus (ISO 178), notched Izod impact (ISO 180/A), Vicat B50 (ISO 306), and heat deflection temperature (ISO 75-2).

What separates Hepla H1100 HG T from general-purpose ABS in tooling and part design?

The primary differentiation is the simultaneous retention of specular gloss and room-temperature notched impact. General-purpose ABS grades commonly show melt volume-flow rates of 20–40 cm³/10 min at 220 °C/10 kg (ISO 1133-1:2022) and fill long paths easily, but the 60° gloss may be below 90 GU or low-temperature toughness may fall below 4–8 kJ/m² at −30 °C (ISO 180/A). High-heat ABS grades with Vicat B50 above 103 °C (ISO 306) supply greater thermal resistance, but notched Izod impact at 23 °C frequently falls below 15 kJ/m². ABS/PC blends provide better low-temperature ductility and heat resistance but require higher melt and mould temperatures and may exhibit lower surface hardness. The high-gloss toughened ABS class represented by H1100 HG T is specified where the moulded wall of 1.2–2.5 mm must maintain 60° gloss above 90 GU (ISO 2813) while room-temperature notched impact remains above 18 kJ/m² (ISO 180/A).

Batch-to-batch variation in rubber grafting, styrene-acrylonitrile molecular weight distribution, and additive package can shift these class values by approximately 5%. Production qualification should therefore use the supplier’s technical datasheet and a first-article inspection on the intended tool, because the table represents comparative engineering classes rather than certified lot-specific H1100 HG T results.

Pre-drying in a closed-loop desiccant dryer at 80 °C ± 5 °C for 2–4 h with dew point ≤ −30 °C is required until residual moisture is below 0.05 wt% (ISO 15512 Method B). Insufficient drying produces silver streaks, splay, and brittle knit lines. A reciprocating-screw injection moulding machine with a screw L/D ratio of 20:1–25:1 and compression ratio of 2.0:1–2.5:1 is suitable. Typical barrel temperatures from feed to nozzle are 210 °C, 230 °C, 240 °C, and 245 °C; melt temperature measured at the nozzle should be 220–250 °C. Mould wall temperature is maintained at 60–80 °C for high-gloss surfaces. A lower mould temperature of 40–50 °C reduces cycle time but increases gloss variation and flow-mark visibility. Injection speed is set at 100–200 mm/s for wall thickness 1.5–2.5 mm. Holding pressure is maintained at 60–80% of peak injection pressure, and holding time is based on gate seal time rather than part weight to avoid sink marks and dimensional variability.

High-gloss toughened ABS has a narrow mould-temperature corridor. At mould wall temperatures below 50 °C, the quenched surface freezes before the polymer replicates the polished cavity, and 60° gloss can fall below 80 GU (ISO 2813). At melt temperatures above 260 °C, thermo-oxidative degradation of the polybutadiene rubber phase accelerates, producing yellowing and a reduction in notched Izod impact at 23 °C of more than 15% (ISO 180/A). Residence time at melt temperature should be limited to 15 min. Cavity pressure transducers are recommended on all-electric machines with clamp forces from 500 kN to 2000 kN; velocity-to-pressure switch-over is set at 95–98% of cavity fill volume.

Capillary rheometry on high-gloss ABS at 230 °C (ASTM D3835) typically shows apparent shear viscosity decreasing from approximately 300 Pa·s at 100 s⁻¹ to 60 Pa·s at 1000 s⁻¹. This shear-thinning behaviour supports thin-wall fill but increases the sensitivity of molecular orientation to injection speed. Gate shear rate should be kept below 100,000 s⁻¹ for unfilled ABS to avoid burn marks and surface defects. Lot-specific capillary or slit rheometry data for H1100 HG T should be measured on dry pellets because moisture shifts viscosity and destabilizes the viscoelastic response.

Surface Aesthetics and Mechanical Performance Trade-Offs

For high-gloss ABS, the 60° specular reflectance is governed by rubber particle size distribution and mould surface replication. A fine rubber phase reduces light scattering, but a minimum rubber content is required for crack arrest. This is why high-gloss grades often show notched Izod impact values of 18–35 kJ/m² at 23 °C but fall to 8–15 kJ/m² at −30 °C (ISO 180/A). The mould cavity must be polished to a surface roughness of Ra 0.02–0.05 µm for the gloss target to be reached. A texture of Ra 1.5–3.0 µm suppresses gloss and reduces fingerprint visibility but does not alter intrinsic toughness. High-gloss ABS has pencil hardness in the range HB–F (ASTM D3363); it is not hard-coated, and visible scratches require a separate clear hard coat or secondary surface treatment.

The high-gloss/toughened balance in ABS depends on graft morphology. During bulk or emulsion polymerization, styrene-acrylonitrile copolymer is grafted to polybutadiene particles; the degree of grafting controls interfacial adhesion. If grafting is too low, impact delamination occurs at the rubber particle interface. If grafting is too high, the rubber phase is stiffened and low-temperature impact declines. This is why notched Izod impact and 60° gloss can move in opposite directions when formulation changes are made. The H1100 HG T designation implies a controlled grafting architecture, but the supplier’s technical datasheet and production trial are required to confirm the balance on a given tool.

In thin-wall electronic enclosures with nominal wall thickness 1.2–2.5 mm, the high-gloss ABS melt at 240 °C typically achieves a flow-path-to-wall-thickness ratio of 100:1 to 150:1 on a 500 kN clamp injection machine. Exceeding this ratio through a single edge gate can create short shots and severe orientation, visible as gloss shift around the gate. Valve-gated hot-runner systems with sequential opening from the centre outward are preferred for fascias wider than 200 mm. For appliance control panels exposed to household cleaners, the part should be evaluated under simulated service using the intended cleaning formulation, because stressed ABS in contact with ketones, esters, or halogenated hydrocarbons can show environmental stress cracking. If flame retardancy to UL 94 V-0 at 1.5 mm is required, a specifically flame-retarded ABS or ABS/PC formulation is normally necessary; unfilled high-gloss ABS is typically UL 94 HB.

Automotive interior trim uses the material class for high-gloss bezels and decorative panels where service temperature does not exceed the Vicat B50 limit and ultraviolet exposure is indirect. For painted or coated parts, adhesion promoter systems containing chlorinated polyolefins are applied before topcoat; cross-hatch adhesion is assessed by ISO 2409 after 72 h of water immersion at 40 °C. Unpainted ABS is not recommended for exterior use because polybutadiene photo-oxidation causes yellowing, gloss loss, and surface chalking. Grain retention after injection moulding is governed by pack pressure and cooling rate; deep-textured surfaces with average texture depth above 100 µm require higher holding pressure and may exhibit spring-back and unacceptable visual distortion if demoulded too early.

Weld-line strength in high-gloss ABS is a critical process conflict. In ISO 527-2 tensile specimens moulded with a single edge gate and a directly opposite gate, retained tensile strength at the weld line is typically 60–80% of the un-welded value. High-gloss grades with high flowability tend to form V-notch-shaped weld lines on the surface, which reduces gloss retention at the knit line. Sequential valve-gate control, elevated mould temperature, and local gas counterpressure can raise weld-line strength, but each adds cycle time and tooling complexity. For parts with multiple bosses on the appearance surface, gas-assisted moulding is generally unsuitable because gas channels create visible surface irregularities; microcellular foaming is also not recommended for high-gloss surfaces because surface silver streaks and swirl marks violate the cosmetic standard.

Moisture uptake in ABS is modest; equilibrium moisture content at 23 °C and 50% relative humidity is approximately 0.2–0.35 wt%. However, residual moisture above 0.05 wt% can hydrolytically degrade molecular weight during plastication and produce splay. Regranulated material should be limited to 20–30% by weight when high gloss and notched impact retention are specified, and regrind must be pre-dried separately because bulk density differences alter feed consistency and melt temperature.

For electrical and electronic enclosure applications, the material class is assessed under EU RoHS Directive 2011/65/EU Annex II and REACH Article 33. Supplier certification is required for each lot because pigment and additive packages can affect the presence of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, and the four restricted phthalates. Food-contact applications are not presumed compliant with EU 10/2011 or FDA 21 CFR 177.1020 unless explicitly certified by the supplier, because high-gloss ABS may contain additives that affect overall migration and specific migration limits under the intended food simulant and time-temperature condition.

When the application imposes low-temperature impact or chemical exposure demands

If the component must absorb notched Izod impact above 30 kJ/m² at −30 °C or withstand continuous service above 105 °C, H1100 HG T should be compared with ABS/PC or high-heat ABS grades. The polybutadiene rubber in ABS has a glass transition near −80 °C, but the styrene-acrylonitrile matrix and graft interface reduce low-temperature ductility relative to polycarbonate-modified systems. Chemical resistance testing should use a defined stress jig and the intended chemical formulation, because environmental stress cracking in ABS depends on stress level, chemical concentration, temperature, and exposure time. Skin oils and dilute household cleaners are generally tolerated at room temperature but may produce microcrack networks in stressed bosses. For outdoor exposure, unpainted ABS loses gloss and embrittles after 500–1000 h of xenon arc weathering (ISO 4892-2); ASA or a UV-screening cap layer is preferred for direct exterior use.