INEOS Styrolution ABS TERLURAN HH-106 is a high-heat acrylonitrile-butadiene-styrene injection-molding grade within the Terluran family. The grade designation HH indicates high heat resistance, and the numeral 106 corresponds to a Vicat softening temperature of 106 °C determined under ISO 306 Method B50. Typical melt volume-flow rate is 5 cm³/10 min at 220 °C and 10 kg load in accordance with ISO 1133-1. Density is reported as 1.05 g/cm³ under ISO 1183-1. The material combines moderately high flow with elevated short-term heat resistance, making it suitable for injection-molded housings, automotive interior structural parts, electrical enclosures, and appliance components that must resist dimensional distortion during paint drying or hot-service conditions. Compared with general-purpose Terluran GP-22, HH-106 trades melt flow for heat resistance. Compared with high-impact Terluran HI-10, it offers higher Vicat performance but lower notched impact at room temperature. All values cited are typical values from published technical data and are not specification limits.

What Distinguishes High-Heat ABS Grade HH-106 from General-Purpose and High-Impact Terluran Grades?

The primary difference between HH-106 and lower-temperature ABS grades is the distribution of the butadiene rubber phase and the composition of the styrene-acrylonitrile matrix. General-purpose ABS grades typically optimize melt flow and surface appearance for rapid filling of large-area tools, while high-impact grades increase rubber content to raise Charpy notched impact at the expense of heat deflection and stiffness. HH-106 is positioned between these classes: its Vicat softening temperature is approximately 10 K above general-purpose ABS, but its melt volume-flow rate is significantly lower, requiring higher injection pressure or larger gate cross-sections for equivalent filling length. The following representative values are drawn from published technical data sheets for Terluran HH-106 and adjacent Terluran grades; they are not intended for product specification.

From a formulating perspective, the higher heat resistance of HH-106 is achieved through a more restricted rubber-phase morphology and a styrene-acrylonitrile matrix with a higher glass transition temperature. The trade-off is a reduction in room-temperature impact and a narrower processing window. When a tool designed for GP-22 is converted to HH-106, sprue and runner dimensions may need enlargement because the lower MVR increases filling pressure drop across cold runners and hot-runner drops.

Application use cases are driven by the Vicat number rather than continuous-use temperature. HH-106 is frequently selected for painted automotive interior trim where off-line drying after paint application can expose the substrate to 100 °C for up to 30 min. In electrical enclosures, the grade is used where internal heat from transformers or busbars creates local surface temperatures near 90 °C. For appliance housings, it is chosen for parts adjacent to heated surfaces such as washing machine fronts, iron soleplate covers, and microwave trim, where lower-heat ABS may deflect or lose snap-fit retention. These uses require mold design with generous radii and minimized notch sensitivity because the material’s low-temperature impact is lower than that of high-impact ABS grades.

Drying, Melt Rheology, and Screw Recovery in Heated Injection Tooling

Moisture management is a process threshold for HH-106. Residual pellet moisture above 0.1% by weight produces splay, voids, and degraded impact performance during injection molding. Desiccant drying at 80 °C for 2 h to 4 h is the standard baseline. At ambient relative humidity above 60%, extended drying or sealed hopper loading is required. The dryer dew point should be maintained at or below -20 °C. Melt temperature is normally controlled between 240 °C and 260 °C, with a preferred maximum of 270 °C to avoid thermo-oxidative attack on the polybutadiene phase. Mold temperature is typically 60 °C to 80 °C, which promotes weld-line strength and reduces internal stress. Screw geometry for ABS processing commonly uses an L/D ratio of 20:1 to 25:1 and a compression ratio of 2.0:1 to 2.5:1. Excessive shear heating in the transition zone can raise melt temperature above the setpoint and generate black specks.

In production-scale trials on hot-runner tools, the limiting variable is often screw recovery time rather than injection speed. Because HH-106 has a lower melt volume-flow rate than general-purpose ABS, the plasticating unit must rotate longer to prepare the shot, which can increase residence time in the barrel. The melt residence time distribution across the screw is non-uniform. Polymer near the barrel wall experiences longer thermal history than the center stream. This distribution must be accounted for when setting screw backpressure and barrel temperature profile. Published data for specific hot-runner configurations with HH-106 is limited, so tool trials remain necessary when gate geometry is complex.

Thermal degradation in HH-106 proceeds primarily through oxidation of the polybutadiene domains and chain scission in the styrene-acrylonitrile matrix. At melt temperatures above 270 °C, visible yellowing and brown streak formation appear within a few minutes of static residence time. Degradation onset is accelerated by stagnant melt zones in hot-runner manifolds, decompression ports, or improperly purged check rings. In fast-cycling thin-wall molding, shot weights below 20% of barrel capacity can extend residence time beyond 5 min, which is the practical upper limit at 260 °C for retaining Charpy notched impact. When the molded part is painted or electroplated, these degradation products can also reduce adhesion uniformity and contribute to surface defects in subsequent finishing.

When Barrel Residence Time Exceeds 5 Minutes at 260°C

Process conflicts arise when a high-heat ABS grade is molded on equipment configured for lower-temperature ABS. The higher barrel settings required for HH-106 simultaneously reduce melt viscosity but accelerate thermal degradation. If the cycle is interrupted, the stable processing window narrows: at 260 °C, a residence time of 5 min is the recommended maximum before purging. At 270 °C, the maximum residence time drops to approximately 3 min. These limits are not sharp chemical thresholds but operational guidelines; color shift and impact loss are progressive. In hot-runner systems with multiple drops, the slowest-flowing cavity dictates residence time. A cavity that fills slowly at the end of fill may experience local melt temperatures above 265 °C while the adjacent cavity remains below 250 °C, leading to non-uniform mechanical properties within the same shot. Correcting this requires balanced runner sizing, sequential valve-gate timing, or cavity-specific cooling controlled within ±5 °C.

High-shear dispersion in the gate area can also generate frictional heat. For a 1.0 mm gate thickness and high injection velocity, local melt temperature can exceed the barrel setpoint by 10 K to 20 K. Under these conditions, the polybutadiene phase may crosslink or degrade, producing the characteristic brown streaks and reducing notched impact. The practical mitigation is to increase gate cross-section or reduce injection velocity, but this must be balanced against the hesitation marks that occur when melt flow slows in thin-wall sections. These process interactions are specific to HH-106 compared with higher-flow ABS grades because the lower MVR demands higher pressure, which in turn increases shear heating.

Comparative Mechanical Data under ISO 527-2, ISO 179-1, and ISO 306

Mechanical characterization of HH-106 is dominated by the trade-off between stiffness and impact. Under ISO 527-2, tensile modulus is approximately 2500 MPa, and yield stress is reported near 50 MPa. Under ISO 179-1, Charpy notched impact strength is approximately 14 kJ/m² at 23 °C and falls to approximately 7 kJ/m² at -30 °C. Heat deflection temperature under ISO 75-2/A is approximately 101 °C, while Vicat softening temperature under ISO 306 Method B50 is 106 °C. These values place HH-106 between general-purpose ABS and high-impact ABS: the material is stiffer and more heat-resistant than high-impact grades but less tough at room and low temperature.

Dimensional stability after demolding is influenced by mold temperature and packing pressure decay. Mold shrinkage for HH-106 is typically in the range of 0.4% to 0.7% depending on wall thickness, gate location, and packing pressure. Post-mold shrinkage can occur if parts are exposed to continuously elevated temperatures above 85 °C. Compared with amorphous glass-filled ABS or ABS/polycarbonate blends, HH-106 does not carry the same continuous-use temperature rating and should not be substituted where sustained service above 95 °C is required. The grade is also not UV-stabilized in its standard form. Prolonged outdoor exposure without carbon black or additional stabilization causes photo-oxidative chalking and reductions in surface gloss. In such cases, ASA grades such as Luran S are preferred.

When an additional step change in heat resistance is required, ABS/polycarbonate blends or ASA/polycarbonate blends are often considered. HH-106 provides an intermediate solution at lower formulation complexity. Compared with an unfilled ABS/polycarbonate blend with a Vicat softening temperature near 120 °C to 130 °C, HH-106 offers easier processability but lower continuous-heat performance. Published data for direct replacement of ABS/polycarbonate blends with HH-106 is limited, particularly in metalized applications where thermal expansion mismatch and electroplating adhesion are critical.

Regulatory Documentation Is Not a Certification in Itself

The material is subject to standard polymer regulatory documentation. Compliance with REACH Regulation (EC) No 1907/2006 must be confirmed through the manufacturer’s substance declaration. RoHS Directive 2011/65/EU compliance for homogeneous materials is typically addressed in the supplier declaration, but the burden of validation falls on the end-product manufacturer. Food-contact status under FDA 21 CFR 177.1020 or EU 10/2011 is grade-specific and must not be assumed for HH-106 without written confirmation from INEOS Styrolution. Flame-retardant requirements are not met by standard HH-106; the grade is typically classified as UL 94 HB unless a flame-retardant variant is specified. The following matrix summarizes documentation categories but does not constitute a certification.

Operational boundaries include pre-drying at 80 °C for 2 h to 4 h, a melt-temperature ceiling of 270 °C, and a residence-time limit of 5 min at 260 °C. The grade should not be blended with regrind beyond the manufacturer’s recommended ratio because repeated heat history degrades the polybutadiene phase and widens the batch-to-batch impact distribution. Incompatibility is noted with strong solvents, including ketones, esters, and chlorinated hydrocarbons, which can induce environmental stress cracking in molded parts under residual stress. The material should not be exposed to amine-based mold-release agents or certain silicone-based external lubricants without prior screening, as these can interfere with adhesion in painting, plating, or bonding operations.