INEOS Styrolution ABS NOVODUR P3MC is an acrylonitrile-butadiene-styrene injection-moulding grade classified within the ISO 2580-1 designation system. The product is a two-phase thermoplastic in which a grafted polybutadiene rubber phase is dispersed in a styrene-acrylonitrile copolymer continuous phase. This morphology provides a balance of stiffness, dimensional stability, and impact resistance for technical injection mouldings. Published datasheet values for the natural grade include a density of 1.04 g/cm³ determined to ISO 1183-1, a melt volume-flow rate of approximately 24 cm³/10 min at 220 °C under 10 kg load measured according to ISO 1133-1, a tensile modulus of approximately 2300 MPa tested to ISO 527-1/2, a tensile yield stress of approximately 45 MPa, and a notched Charpy impact strength at 23 °C of approximately 21 kJ/m² determined to ISO 179-1/1eA. The Vicat softening temperature B50 is approximately 96 °C under ISO 306. These values refer to the natural, unmodified grade and may shift with pigmentation, regrind content, or additive packages.

Because the polybutadiene phase controls impact energy absorption, lot-to-lot melt volume-flow rate and rubber-phase particle-size distribution are controlled within narrow limits. The material is supplied in free-flowing pellet form and should be handled with residual moisture below 0.1 % before melt processing. Although P3MC is not hygroscopic to the level of polyamide or polycarbonate, surface moisture absorbed during transport or storage in ambient relative humidity above 60 % can produce splay defects if the material is not dried. Typical pellet bulk density for this ABS class is approximately 600–650 kg/m³; hopper bridging is uncommon when the pellet surface is free of fines and the hopper is not exposed to direct condensation.

Why does melt volume-flow rate govern thin-wall filling pressure in P3MC?

The reported 24 cm³/10 min MVR places P3MC in the high-flow segment of general-purpose ABS injection-moulding grades. In thin-wall parts with nominal wall thickness below 1.2 mm, the pressure gradient along the flow length is a function of melt viscosity at high shear rates and solidification layer formation at the cold cavity wall. P3MC exhibits shear-thinning behaviour typical of ABS; apparent viscosity decreases with increasing injection shear rate, so fast filling can reduce overall pressure demand. On 80–100 t toggle-clamp injection moulding machines equipped with 20:1 L/D general-purpose screws, melt temperatures of 240–260 °C and mould temperatures of 40–80 °C are sufficient to maintain fill in multi-cavity tools where flow-length-to-thickness ratios exceed 150:1. Specific injection pressure in such tools is regularly observed in the range 800–1200 bar. For valve-gated hot-runner systems, manifold and nozzle setpoints should be held within ±5 °C of the barrel front-zone temperature to avoid either cold-slug formation or local thermal degradation. Pressure imbalance across cavities in hot-runner tools can be reduced by using balanced runner layouts and by controlling hot-runner temperature zones to ±2 °C.

Tensile property evaluation according to ISO 527-1:2019 and ISO 527-2:2012 on type 1A specimens injection-moulded at 260 °C melt temperature indicates a tensile modulus of approximately 2300 MPa and a yield stress of approximately 45 MPa. Elongation at yield is approximately 2.5 %; elongation at break for natural material is generally above 10 %. For moulding grades, test specimen fabrication history influences these values because molecular orientation and residual stress introduced by injection speed and holding pressure can shift tensile yield stress by 2–5 %. Flexural properties determined to ISO 178:2019 are in the range 2200–2400 MPa for modulus and approximately 65 MPa for flexural strength. In repeated loading, design stress should remain below the tensile yield stress after applying an appropriate safety factor; the creep modulus at 23 °C and 1000 h is lower than the short-term tensile modulus, but published creep curves for this specific grade are limited.

Tensile, flexural, and notched impact response at 23 °C and −30 °C

Charpy notched impact testing to ISO 179-1/1eA on edgewise specimens cut from 4 mm plaques gives a 23 °C value of approximately 21 kJ/m². At −30 °C the value falls to approximately 8 kJ/m². The reduction indicates a ductile-to-brittle transition associated with the glass transition of the polybutadiene rubber phase; below −30 °C energy absorption is increasingly governed by crazing rather than shear yielding. For parts expected to contain sharp corners, weld lines, or moulded-in inserts, low-temperature impact testing should be performed on prototype parts because notch sensitivity increases with thickness and with injection-moulded orientation. The ratio of 23 °C to −30 °C notched impact values is approximately 2.6:1. In multi-axial impact testing such as ISO 6603-2, published puncture energy data for this specific grade is limited; end users should generate part-level data for safety-relevant housings.

Pre-drying is recommended when residual moisture exceeds 0.1 %, when material has been stored in ambient relative humidity above 60 % for more than 30 min, or when production history shows splay defects. A desiccant dryer set to 80 °C for 2–4 h reduces moisture to the required level. Hopper residence at 80 °C beyond 4 h can cause yellowing of the styrene-acrylonitrile matrix, particularly in natural or light-coloured parts. Barrel zone temperatures are typically profiled from 220 °C in the rear zone to 250 °C at the nozzle. Melt temperature should not exceed 270 °C; excursions above 280 °C or residence beyond 5 min in the barrel can generate brown streaks, reduce notched impact due to polybutadiene oxidation, and cause moulded-in black specks. Screw back pressure of 5–15 bar hydraulic is sufficient for melt homogeneity; back pressure above 20 bar can increase shear heating and may degrade the rubber phase. Screw surface velocity during recovery is generally set between 0.1–0.3 m/s. Hot-runner manifolds and valve pins should be inspected for dead spots after 8 h continuous operation because stagnant melt can carbonize and generate black contaminants.

Mould shrinkage for P3MC is anisotropic and thickness-dependent. Typical linear mould shrinkage after 24 h at 23 °C is reported in the range 0.4–0.7 % parallel to flow and 0.3–0.6 % transverse to flow in 2 mm plaques. Post-mould shrinkage can continue for 24–48 h; dimensional measurements on tight-tolerance components should be delayed accordingly. Warpage in flat parts is influenced by packing pressure, gate location, and mould temperature uniformity. Cooling channels should maintain cavity surface temperature variation below ±5 °C to minimize differential shrinkage; a turbulent coolant flow with Reynolds number above 10,000 is typical for consistent cooling.

If P3MC replaces a lower-flow ABS in a hot-runner tool

Substitution of P3MC for a lower-flow ABS reduces filling pressure but shifts packing and gate-seal behaviour. In cold-runner tools with tunnel gates, the lower melt viscosity can reduce gate-seal time; holding pressure may need to be increased by 10–20 % to maintain adequate packing. Valve-gated hot-runner systems may require an injection profile with a fast initial injection velocity of 40–60 mm/s followed by a pack velocity of 10–20 mm/s to prevent gate blush. The P3MC Vicat softening temperature of approximately 96 °C is lower than high-heat ABS grades that may reach 103–115 °C; therefore a direct substitution in underhood or continuously load-bearing hot-surface applications is not advisable. Compared with high-impact ABS grades containing higher polybutadiene content, P3MC may exhibit lower notched impact; some high-impact ABS grades exceed 30 kJ/m² at 23 °C. In contrast, P3MC has higher flow and is easier to fill in thin walls than grades with notched impact above 30 kJ/m². Substitution for extrusion-grade ABS is not recommended because P3MC has lower melt strength and narrower processing latitude for profile or sheet extrusion.

For injection-moulding simulation, P3MC can be characterized using Cross-WLF viscosity parameters derived from capillary rheometry; commercial simulation databases often list the grade under the supplier designation. Apparent viscosity at 240 °C and 1000 s⁻¹ is in the range 200–300 Pa·s for natural ABS of this MVR class. These values should be used only as starting points because colour and regrind alter high-shear viscosity and thermal conductivity. The heat deflection temperature under 1.8 MPa is approximately 90–95 °C; under 0.45 MPa it is approximately 95–100 °C. Shrinkage and warpage predictions should use measured pressure-volume-temperature data for the specific colour and regrind level; published pvT data for this specific grade in open literature is limited.

Reported application areas for P3MC include small appliance housings, vacuum cleaner components, electrical switch covers, toys, and cosmetic packaging closures. For electrical/electronic enclosures, the natural grade is typically classified as HB at 1.5 mm thickness under UL 94; the current UL Yellow Card for the specific colour and lot should be consulted before certification. The material is not inherently UV-stabilized; outdoor unpainted parts exposed to 300 h of accelerated weathering to ISO 4892-2:2013 may show surface dulling and loss of impact due to oxidative degradation of the polybutadiene phase. A UV-stabilized or painted grade should be specified for exterior components. Chemical compatibility is typical for ABS: resistance to aqueous detergents and dilute acids is acceptable at room temperature, but aromatic hydrocarbons, ketones, esters, and chlorinated solvents can induce stress-cracking. Contact with cleaning agents should be assessed by ISO 22088-3 or a part-level environmental stress-cracking test. The upper continuous service temperature in air without load is approximately 70–80 °C; under sustained mechanical load or chemical exposure the practical limit is lower.