INEOS Styrolution ABS TERLURAN HH-104 is a high-heat acrylonitrile-butadiene-styrene copolymer supplied as cylindrical pellets for injection moulding and, to a lesser extent, profile extrusion. Under the designation system of ISO 2580-1:2004, the grade is classified as an ABS moulding material with elevated Vicat softening temperature; the suffix HH-104 corresponds to a Vicat B/50 value of approximately 104 °C when tested according to ISO 306:2022. Manufacturer literature lists automotive interior structural parts, heating/ventilation/air-conditioning ducts, loudspeaker grilles, and appliance housings as primary conversion routes. Published datasheet values should be treated as centroid values for natural colour; lot-specific certificates of analysis govern actual production validation because pigmentation, regrind level, and trapped moisture influence the final test results.

How Does the High-Heat Architecture Affect Short-Term Thermal Performance?

Vicat softening temperature is determined under ISO 306:2022 using method B/50, in which a 50 N load and 50 °C/h heating rate are applied to a standard test specimen. For TERLURAN HH-104, the method B/50 value is approximately 104 °C; this is typically 8–10 K higher than general-purpose TERLURAN grades and makes HH-104 suitable for short-term paint-baking or hot-air exposure in automotive interior locations. Heat deflection temperature under a 1.8 MPa flexural load is reported near 96–98 °C using ISO 75-2:2013 method A. The deflection temperature is lower than the Vicat value because the applied stress accelerates relaxation of the rigid SAN-rich phase. Continuous-use temperature is not equivalent to Vicat temperature; for this grade, continuous-load service above 85–90 °C should be supported by creep-modulus data from ISO 899-2:2003 rather than short-term thermal indices alone.

Melt Rheology and Drying Requirements for Injection Moulding Lines

High-heat ABS exhibits higher melt viscosity than general-purpose ABS at equivalent barrel temperatures. Apparent viscosity measured by capillary rheometry at 250 °C and shear rates between 100 s⁻¹ and 1000 s⁻¹ generally falls in the 150–400 Pa·s range for injection moulding grades; processors should reference the manufacturer's viscosity curve for lot-specific values. The increased viscosity raises screw recovery torque and can generate adiabatic overheating in undersized screws. On production-scale injection moulding machines with clamping force between 1000 kN and 6500 kN, a general-purpose screw with a length-to-diameter ratio of 20:1 and compression ratio of 2.0–2.5:1 is adequate for standard parts. For thin-wall parts below 2.5 mm, screws with higher mixing intensity and L/D near 22:1 are preferred to homogenise melt temperature without raising barrel set-points.

The material is hygroscopic. Pellets exposed to ambient conditions above 60% relative humidity require dehumidified-air drying at 80 °C for 2–4 h to a residual moisture target below 0.1% before melt processing. Dryers controlled to a dew point of -30 °C or lower produce consistently low splay and better gloss retention. Regrind addition up to 20 wt% is generally tolerated if the regrind is dry and free of dust; higher levels shift melt viscosity and reduce notched impact due to cumulative thermal history. The SAN phase is susceptible to thermo-oxidative yellowing when melt temperature exceeds 280 °C or residence time exceeds 10 min; the butadiene phase can also gel. Purging after shutdown should use a low-viscosity acrylic or HDPE purge compound, not PVC, to avoid acid generation in the barrel.

Injection velocities of 100–200 mm/s are commonly used for thin walls to prevent premature freeze-off; however, excessively high shear rates above 10 000 s⁻¹ can induce surface haze at gates. Gate location should place weld lines away from direct high-velocity vent air because weld-line tensile strength measured on double-gate plaques under ISO 527-2:2012 is typically 60–80 % of the un-notched value in ABS. Injection moulding trials have shown that mould temperatures below 50 °C increase internal stress, gloss variation, and susceptibility to environmental stress cracking.

If Dimensional Tolerance Below 90 °C or Immersion in Weak Acid Media Is Required

TERLURAN HH-104 is not an intrinsically dimensionally stable material under load; short-term thermal resistance does not imply low creep. The coefficient of linear thermal expansion for ABS is typically 80–110 × 10⁻⁶ K⁻¹ according to ISO 11359-2:2021. Parts with tight dimensional windows should use mould shrinkage compensation according to ISO 294-4:2018; measured flow-direction shrinkage is commonly 0.4–0.7 %, with transverse shrinkage up to 0.6–0.8 %. In applications where hot air from a defroster impinges on an instrument panel carrier, the part must not be rigidly constrained because differential expansion against metal brackets can initiate stress cracking. Finite-element simulations should use creep-modulus values generated under ISO 899-2:2003 at the service temperature rather than short-term tensile modulus.

Chemical resistance to dilute acids and alkalis is acceptable at ambient temperature. Immersion testing under ISO 2812-2:2007 commonly shows moderate mass gain without visible attack in 5 % acetic acid or 5 % sodium hydroxide at 23 °C for short exposure; however, stress-cracking solvents such as toluene, ethyl acetate, and methyl ethyl ketone must be avoided. Published data for this specific grade under continuous immersion at elevated temperatures is limited, and conversion trials should include chemical exposure with the actual production fluid.

Chemical Compatibility Boundaries and Ultraviolet Ageing Response

Absence of butadiene-phase ultraviolet stabilisation is a boundary condition. The material is not classified as UV-stable and should not be specified for unpainted exterior components unless a UV absorber and hindered amine stabiliser system is compounded at the converter or a protective cap layer is used. Xenon-arc exposure under ISO 4892-2:2013 has shown that standard ABS yellowing and gloss loss begin before mechanical embrittlement; the exact failure threshold depends on pigment loading and part thickness. For exterior unpainted parts, ASA or PC/ASA should be selected instead. Environmental stress cracking can be evaluated using ISO 22088-2:2006 with a constant strain method; ABS is particularly sensitive to esters, aromatic hydrocarbons, and chlorinated solvents. Compatibility with coolants, windshield washer fluids, and cleaning agents must be tested because blends containing ethylene glycol mono-butyl ether can induce stress cracking in amorphous thermoplastics. Avoid contact with glycol ethers in water-based paints and with plasticised PVC seating or adhesive films that can migrate plasticiser into the ABS surface.

Automotive heating, ventilation, and air-conditioning components represent the largest conversion route for TERLURAN HH-104. In production-scale injection moulding cells using 1200 kN to 3000 kN clamp force and valve-gated hot runners, the grade has been used for defroster grilles, upper airbag trim panels, and pillar mouldings where the peak soak temperature after a summer heat cycle can exceed 95 °C but total sustained load is low. For these parts, gate location is selected so that weld lines are not placed in direct line of high-velocity vent air; weld-line strength measured by tensile testing on double-gate plaques under ISO 527-2:2012 is typically 60–80 % of the un-notched value in ABS grades. Part geometry determines whether that reduction is acceptable.

Benchmarking Against General-Purpose and High-Impact Terluran Grades

Compared with general-purpose TERLURAN GP-22, HH-104 shifts the Vicat B/50 upward by approximately 8 K while melt viscosity increases and low-temperature impact declines. The exact property spread depends on colourant: carbon black, titanium dioxide, and organic pigments alter nucleation and embrittlement. High-impact TERLURAN grades with higher butadiene rubber content can offer notched Charpy values above 25 kJ/m² at 23 °C, whereas the high-heat architecture of HH-104 typically falls in the 18–22 kJ/m² range; selection between high-heat and high-impact ABS is therefore controlled by whether hot bearing strength or ductile impact resistance is the first failure mode. Against polycarbonate/ABS blends, HH-104 has lower heat deflection temperature under load, lower notched impact, and lower raw-material cost; against ASA, HH-104 lacks exterior weatherability. These differences are documented in manufacturer datasheets and should be confirmed with current certificates of analysis.

Shrinkage anisotropy under ISO 294-4:2018 is an often-overlooked discriminator. The high-heat grade's higher melt temperature typically produces slightly greater flow-direction shrinkage than standard ABS; mould designs should not simply reuse tools cut for general-purpose ABS without verifying gate and runner dimensions. Production moulds for HH-104 benefit from larger cold slug wells and polished runner surfaces to counteract the narrower processing window. Regulatory compliance statements regarding REACH Regulation (EC) No 1907/2006 and Directive 2011/65/EU are supplied through the material safety data sheet and should be verified for each shipment because additive packages can vary by region.