Versalis SINKRAL M 112 is a general-purpose acrylonitrile-butadiene-styrene injection-moulding grade produced by Versalis S.p.A. The material is positioned for thin-wall technical parts in which melt fluidity, dimensional stability, gloss control, and mechanical consistency are specified. Typical published data for the grade include a density of 1.04 g/cm³ under ISO 1183-1:2019 and a melt mass-flow rate of 25 g/10 min at 220 °C with a 10 kg load according to ISO 1133-1:2022. Moulding shrinkage is stated as 0.4–0.7 % under ISO 294-4:2018; moisture absorption after 24 h immersion is given as 0.3 % under ISO 62:2008. The granules are available in natural and pre-coloured forms, and colour concentrates require verification for dispersion, melt stability, and compatibility with the stabiliser package. The reported values are typical results and are not release limits. The grade is not a modified polyphenylene ether, a polycarbonate alloy, or a flame-retardant ABS; its property profile belongs to the medium-impact high-flow class within the SINKRAL ABS portfolio.

What process window governs SINKRAL M 112 in thin-wall injection moulding?

Pre-drying is mandatory when the granulate moisture content exceeds 0.05 %. The reference drying condition is 80 °C for 2–4 h in a dehumidifying dryer with a dew point not higher than −20 °C. At ambient relative humidity above 60 %, the drying time is extended or the hopper is fitted with a closed-loop dry-air supply. Moisture contents above 0.05 % cause splay, silver streaks, surface defects, and reductions in notched impact resistance through hydrolysis of the rubber phase. The melt temperature at the nozzle is maintained between 230 °C and 250 °C. A typical four-zone barrel profile is 210–230 °C, 220–240 °C, 230–250 °C, and 230–250 °C from feed throat to nozzle. The mould wall temperature is controlled between 40 °C and 70 °C; lower temperatures shorten cycle time but increase frozen-in orientation and can reduce the practical flow length by increasing melt viscosity at the flow front. A reciprocating-screw injection unit with a screw L/D ratio of 20:1–24:1 and a compression ratio of 2.0:1–2.5:1 is adequate for the grade. Back pressure is maintained between 0.3 MPa and 0.7 MPa; higher back pressure improves melt uniformity but raises the risk of thermal degradation when the residence time is already high.

On production-scale injection-moulding lines, the fill rate is set to fill the cavity in 0.5–1.5 s for wall sections below 2.0 mm. The hold pressure is commonly 50–70 % of the peak injection pressure, with a hold time established by gate freeze. Screw decompression between 3 mm and 5 mm prevents nozzle drool; excessive decompression introduces air into the melt and causes burn marks. Regrind from the same grade may be incorporated up to 30 %. Higher regrind fractions are associated with lot-to-lot viscosity shift, gloss reduction, and colour drift, particularly in white and light-coloured parts. At melt temperatures near 250 °C, residence times longer than 5 min produce yellowing, odour, and a measurable loss in melt viscosity. In thin-wall tools with flow-length-to-wall-thickness ratios above 150:1, the injection pressure requirement should be calculated with the grade’s melt viscosity; machines with clamp force below 1000 kN may be pressure-limited before they are clamp-limited. Venting depths between 0.02 mm and 0.03 mm are recommended at the end of fill; insufficient venting leads to diesel effect, burn marks, and reduced weld-line strength.

Gate diameter for edge gates is typically 0.5–0.8 times the wall thickness; submarine gates are designed with a land length of 0.8–1.0 mm and a gate diameter of 0.8–1.2 mm. In hot-runner systems, the manifold temperature is kept between 230 °C and 250 °C, and the tip temperature is adjusted to prevent stringing without exceeding 250 °C. Weld lines in ABS are a modulus concentration point; the notched impact at a weld line may be 40–60 % lower than the base material value. For structural ribs, thickness should not exceed 50–60 % of the adjoining wall to avoid sink marks. Ejection pins should have a minimum draft angle of 0.5 °; textured surfaces require an additional draft of 1 ° per 0.025 mm of texture depth. If the tool is run at a cycle time below 30 s, mould-temperature control stability should be verified because the material’s amorphous structure does not create a defined crystallisation plateau, but shrinkage anisotropy remains sensitive to gate location and flow orientation.

Mechanical, thermal, electrical, and rheological reference data

The following table consolidates typical values from the supplier’s technical datasheet. They are single-point laboratory values measured under the specified methods and should not be used as design minima without converters’ release data.

Relative to other ABS grades, SINKRAL M 112 occupies the high-flow segment. The melt mass-flow rate of 25 g/10 min is above the common threshold of 10–12 g/10 min for low-flow ABS, which permits shorter fill times and lower injection pressures in multi-cavity tools. However, the high-flow design is not intended for low-temperature impact service. High-impact ABS grades with ISO 180/1A notched impact values exceeding 30 kJ/m² at 23 °C are preferred when the application must survive crack propagation at sub-zero temperatures or sustained point loads. Conversely, low-flow grades are generally unsuitable for high-cavitation thin-wall tooling, and M 112 is selected when the primary processing constraint is pressure drop or short-shot formation. The grade can also be compared with polycarbonate/ABS blends; PC/ABS materials typically show Vicat B/50 values above 120 °C under ISO 306:2022 and higher notched impact energy but require melt temperatures above 260 °C and often require elevated mould temperatures above 80 °C. SINKRAL M 112 is further distinguished from acrylonitrile-styrene-acrylate by lower retention of surface appearance and mechanical properties after prolonged ultraviolet exposure; unpigmented ABS is not recommended for exterior unpainted parts unless the compound is specifically UV-stabilised. Published data for exact competitive comparisons are limited; equivalence should be established by parallel moulding and release testing under identical standards.

On injection-moulding lines with high-speed robots, static surface attraction of ABS granules can affect regrind conveying; conveying-air velocity is maintained below 12 m/s to limit fines. Feed throat temperature is maintained below 50 °C to prevent bridging. If the grade is changed from another ABS, the screw and barrel are purged with a low-viscosity acrylic or ABS purge compound; residual polycarbonate from a previous run raises melt viscosity and requires a melt temperature increase above 260 °C, which is outside the M 112 reference window. These operational observations are derived from standard ABS handling practice rather than grade-specific published data; local equipment validation is necessary.

When SINKRAL M 112 is evaluated for appliance housings and electrical enclosures

Small appliance housings, vacuum-cleaner structural components, electrical enclosures, and consumer electronic shells are typical application categories. For electrical enclosures, the comparative tracking index of 600 V under IEC 60112:2020 is above the 250 V creepage requirement often used in reinforced-insulation layouts; however, the material is flammability class HB at 1.6 mm under UL 94 and is not a V-0 or 5VA solution. Enclosures carrying an ignition source therefore require a flame-retardant grade or an internal insulating barrier. Moulded-in brass or steel inserts should be preheated to the mould-wall temperature to reduce differential shrinkage and stress cracking around the insert. Screw bosses in appliance housings are designed with a pilot diameter of 0.8 times the screw outer diameter and a depth of at least 2.5 times the screw diameter for self-tapping assembly. For snap-fit features, the design strain is maintained below 1.5 % in unfilled ABS to avoid stress whitening and premature failure. Parts exposed to kitchen oils, aromatic hydrocarbon cleaning fluids, ketones, or esters require chemical compatibility testing; ABS is attacked by some solvents, and stress cracking under load is not predictable from immersion data alone. The grade has no universal European food-contact approval; compliance with EU Regulation 10/2011 must be confirmed for the specific pigment package and conversion line. RoHS conformity is declared under Directive 2011/65/EU as amended, and REACH obligations are addressed under Regulation 1907/2006, but batch-specific verification of heavy-metal content is required for electrical and electronic equipment.