LG Chem ABS HI-100H is an acrylonitrile-butadiene-styrene copolymer in which a grafted polybutadiene rubber phase is dispersed in a styrene-acrylonitrile matrix. The grade is specified for injection moulding of medium-to-large impact-critical housings. Representative density is 1.04 g/cm³ under ISO 1183-1:2019, and melt mass-flow rate is 4 g/10 min at 220 °C under 10 kg load per ISO 1133-1:2022. The polymer is supplied as natural cylindrical pellets; colours are introduced by styrenic masterbatch dilution rather than by polymerisation. Compared with a general-purpose ABS of the same supplier, HI-100H contains a larger rubber-phase volume, which raises notched Izod energy absorption while reducing tensile yield strength and flexural stiffness. Profile extrusion or thermoforming should not be substituted for injection moulding unless melt strength and draw-down have been verified on the specific line.

What Drying and Melt-Residence Constraints Govern Production?

Pre-drying is required before moulding when regrind content exceeds 20 % or when ambient relative humidity exceeds 60 %. A desiccant dryer with a feed-air dew point below -30 °C is recommended; 80 °C air temperature for 2–4 h is sufficient to reach a residual moisture content below 0.02 % by weight. If the hopper throat is unheated, moisture condensation at the feed zone can produce splay and intermittent feeding. During extended production, the hopper should be maintained at 80 °C. Melt temperature measured at the nozzle should be controlled between 210 °C and 250 °C. Holding the resin above 250 °C for more than 5 min accelerates polybutadiene particle agglomeration and SAN matrix yellowing; the consequence is measurable loss of notched Izod performance. In hot-runner manifolds, setpoint above 240 °C should be avoided. Dead corners, sharp changes in runner diameter, and externally heated tips without uniform thermal profiles generate stagnant melt that carbonises into black specks. A screw peripheral speed of 0.15–0.35 m/s and back pressure of 0.5–1.5 MPa limit shear heating. The melt cushion should be held at 3–6 mm; shot-to-shot cushion variation above 2 mm indicates check-ring wear or decompression instability and must be corrected before impact-critical parts are accepted.

Production-scale observations from multi-cavity tools for vacuum cleaner housings with nominal wall thickness between 2.2 mm and 2.5 mm indicate that gate-seal time is approximately 6–9 s when mould temperature is maintained at 50 °C. In these tools, sink marks above bosses are controlled by packing pressure and gate geometry rather than by changing the material to a glass-filled grade. Short-shot studies show that a flow-front temperature above 220 °C at the end of fill prevents visible weld-line cracking in textured surfaces. For parts with snap-fit undercuts, notched Izod values measured on dry-as-moulded specimens should not be used as the sole acceptance criterion; weld-line impact and sharp-corner radius tests must be included because the grade exhibits notch sensitivity under plane-strain constraint. Published data for this specific configuration is limited, so tool-specific validation is required.

Mechanical Property Bands Under ASTM D638 and ASTM D256 Loading

Because ABS is strain-rate dependent, the following values are reported in relation to specimen geometry and loading rate. Tensile yield stress under ASTM D638-14 at 50 mm/min is 44 MPa; elongation at break is typically 20–30 % for injection-moulded 3.2 mm Type I specimens. Flexural modulus under ASTM D790-17 Method A is 2.1 GPa. Notched Izod impact at 23 °C is 38 kJ/m² when measured on ISO 180-1:2019 Type 1A specimens; at -30 °C, the reported band narrows to 9–12 kJ/m², indicating a ductile-to-brittle transition that depends on thickness and notch radius. Rockwell hardness is 102 R scale under ASTM D785. Vicat softening temperature is 96 °C under ISO 306:2022 method B50. Heat deflection temperature at 1.82 MPa is 88 °C under ISO 75-2:2013 method A. Mould shrinkage is 0.4–0.7 % in the flow direction under ISO 294-4:2018, with transverse shrinkage typically 0.5–0.8 %.

Capillary rheometry data for ABS grades in this flow class show apparent viscosity falling from approximately 1,200 Pa·s at low shear to 120 Pa·s at 1,000 s⁻¹ at 220 °C. The shear-thinning response allows filling of long flow paths despite the moderate melt mass-flow rate. Processors should not use melt mass-flow rate as a direct filling index; spiral-flow data at the intended wall section and mould temperature are more relevant for tool design.

Injection Moulding Parameter Corridors, Gate Freeze and Shrinkage Compensation

The recommended mould temperature window is 40–80 °C. For parts above 300 g shot weight or with textured surfaces, a setting of 60–70 °C improves knit-line strength and surface replication but increases cycle time. Injection pressure in the range 70–120 MPa is normal for a 2.0 mm wall section and flow-length-to-thickness ratios below 150:1; thin ribs, long textured surfaces, and sequential valve gating increase peak pressure. Packing pressure should be 50–80 % of peak injection pressure, and hold time must exceed gate-seal time. Gate-seal can be measured by incrementally increasing hold time while tracking part weight until mass asymptote; in edge-fed tools with a 2.5 mm wall, this often occurs at 6–12 s. Backpressure is typically 0.5–1.5 MPa and decompression should be below 5 mm to prevent air ingress and colour streaking. The maximum recommended regrind level is 20 % when regrind is dried, and reclaimed material should not be blended with virgin resin without stabilising the feed ratio. Check-ring wear with clearance above 0.15 mm causes shot-weight drift and should be corrected before producing dimensionally stable housings.

When Low-Temperature Impact Retention Replaces Standard ABS in Enclosures

General-purpose ABS grades typically exhibit tensile yield above 50 MPa and notched Izod values below 20 kJ/m² at 23 °C. HI-100H shifts the property balance toward impact absorption; the grade is therefore substituted when the dominant failure mode is crack initiation at moulded-in bosses, gate vestiges, or snap-fit undercuts. At -30 °C, an unreinforced standard ABS can fall below 6 kJ/m² under notched Izod loading, whereas HI-100H retains 9–12 kJ/m² under the same specimen configuration. This difference is applied in electrical equipment housings, power-tool shells, vacuum cleaner bodies, and automotive interior trim that require assembly clips and low-temperature handling. Heat-resistant ABS grades provide higher Vicat temperature, often above 105 °C, but their lower melt flow and higher processing temperature increase the risk of polybutadiene degradation. Polycarbonate/ABS blends offer greater low-temperature ductility and heat resistance, but require dryer settings near 110 °C and generate higher melt viscosity; HI-100H is selected where simpler drying and the lower melt-temperature corridor are decisive.

Where the moulded article contacts cleaning agents or processing fluids, chemical resistance follows the general ABS pattern. Aromatic and chlorinated hydrocarbons attack the SAN matrix, while concentrated oxidising acids attack the polybutadiene phase. Prolonged hot water contact above 60 °C can reduce mechanical strength and cause surface blush; end-use validation under ASTM D543 is required for housings exposed to detergents or humid heat cycles.

For regulatory documentation, supplier statements indicate that unfilled HI-100H is suitable for restriction of hazardous substances compliance under Directive 2011/65/EU as amended by (EU) 2015/863. Final moulded articles are outside the scope of this statement if additives, pigments, or metal inserts introduce restricted substances. Under Regulation (EC) No 1907/2006, no substance on the REACH candidate list for authorisation is intentionally added to the base polymer; however, Article 33 communication duties apply at 0.1 % weight by weight when a listed substance is introduced downstream. The material is not flame-retardant ABS; a UL 94 HB classification at 3.0 mm is typical for this product class and should not be interpreted as a V-rating.