Guangzhou Keyuan New Material FRABS318-V0 is a flame-retarded acrylonitrile-butadiene-styrene injection-moulding grade intended for electrical enclosures, power-distribution accessory housings, appliance control panels, battery-charging enclosures, and automotive interior brackets where a small-scale vertical burning classification is required in the finished part. The resin is supplied as cylindrical pellets, and its melt is formulated around a halogen-bearing flame-retardant system; the chemical identity of the flame retardant must be confirmed against the supplier safety data sheet before waste-gas treatment or ventilation design is finalised. Density determined under ISO 1183-1:2019 at 23 °C is typically 1.18 g/cm³ to 1.21 g/cm³. Melt flow rate determined under ISO 1133-1:2022 at 220 °C and 10 kg load is typically 18 g/10 min to 24 g/10 min. The grade is normally moulded at a nominal wall thickness of 1.5 mm or 3.0 mm for UL 94 V-0 classification; thinner sections below 1.5 mm require a separate vertical burn test because the rating is thickness-dependent.

Drying Requirements and Screw Configuration

Pre-drying in a desiccant-wheel dryer is required whenever ambient relative humidity exceeds 60% or when regrind exceeds 10 wt%. A drying temperature of 80 °C for 2 h to 4 h at a dew point of -30 °C or lower reduces pellet moisture to a target below 0.08%. Higher moisture levels produce surface splay, jetting marks, and reduced weld-line strength on multi-gate tools. On production-scale injection moulding machines using a general-purpose screw with an L/D ratio of 20:1 to 22:1 and a compression ratio of 2.0:1 to 2.5:1, a barrel temperature profile of 180 °C, 190 °C, 210 °C, 220 °C, and 230 °C from rear to nozzle is a common starting condition. Melt residence time should not exceed 5 min at the upper temperature limit because prolonged thermal load can darken the melt, reduce flame-retardant efficiency, and generate low-level acidic volatiles. Flat profiles below 180 °C are not advised when thin-wall filling below 2.0 mm is required; the resulting viscosity increase can produce short shots on multi-cavity tools with restricted gates.

Injection velocity is adjusted to give a filling time of 1.0 s to 2.5 s for sections between 1.5 mm and 3.0 mm, with holding pressure set at 50 MPa to 80 MPa hydraulic pressure at the machine. Back pressure is maintained at 0.3 MPa to 0.6 MPa. For a 40 mm diameter screw, a screw speed of 40 rpm to 70 rpm is typically sufficient; higher speeds can generate shear heating and discoloration at the flame-retardant particle interface. Mould temperature is controlled at 40 °C to 70 °C using a pressurised water or oil temperature-control unit with a cavity-to-cavity variation not exceeding ±2 °C. Use of hot runner systems is possible, but externally heated hot runner nozzles should maintain temperature control within ±2 °C and avoid idle residence beyond 5 min.

Processors replacing a general-purpose ABS with FRABS318-V0 in existing tools should not assume identical fill behaviour. The flame-retardant package increases the melt’s low-shear viscosity and accelerates solidification at the same mould temperature. Gates designed at the lower end of general-purpose ABS shear-rate limits can produce surface blush or gate smear; increasing the gate land length by 0.2 mm to 0.5 mm or adding a short cold slug well often reduces gate-area defects. Published data for this specific configuration is limited, but industrial practice with flame-retarded ABS indicates that venting depth should be maintained at 0.02 mm to 0.05 mm to avoid gas burns at the end of fill.

What Distinguishes This Grade From General-Purpose ABS and Halogen-Free FR ABS?

The principal difference between FRABS318-V0 and an unmodified general-purpose ABS is the combined effect of density, impact, and thermal stability. General-purpose ABS typically exhibits a notched Charpy impact of 20 kJ/m² to 30 kJ/m² under ISO 179-1:2010 at 23 °C, whereas FRABS318-V0 is expected to fall between 8 kJ/m² and 12 kJ/m². This lowering of impact strength is not a defect but a formulation trade-off required to achieve a UL 94 V-0 classification at 1.5 mm. The flame-retardant system also raises density from about 1.04 g/cm³ to 1.18–1.21 g/cm³. The additional halogenated or inorganic components can reduce paint and adhesive wetting on certain substrate surfaces; processors should require adhesion cross-cut testing under ISO 2409:2020 when post-moulding painting or printing is specified.

Compared with a halogen-free intumescent FR ABS, FRABS318-V0 may require lower flame-retardant additive loading to achieve the same vertical burn performance, which can better retain flexural modulus and surface hardness. However, the trade-off may include higher smoke density and acidic gas evolution in a fully developed fire; therefore, the use of this grade in enclosed public-transport or low-smoke specification applications should be rejected unless the specific formulation is qualified against smoke and toxicity standards. The supplier’s published data for this configuration is limited, and end-users should obtain lot-specific thermogravimetric data and smoke-density values using ISO 5659-2:2017 if regulatory review demands low smoke.

When UL 94 V-0 Thickness Dependence and Mould Shrinkage Are Evaluated Together

For sections below 1.5 mm, the UL 94 V-0 classification cannot be carried over from 3.0 mm test data. A grade rated V-0 at 3.0 mm may be rated V-1 or V-2 at 1.0 mm because the flame-retardant action per unit polymer mass is lower and the specimen loses mass during the first flame application. FRABS318-V0 is typically specified at 1.5 mm and 3.0 mm; for wall thickness below 1.5 mm, a separate test on the actual moulded wall thickness is mandatory. Mould shrinkage under ISO 294-4:2018 is typically 0.4% to 0.6%, with flow-direction shrinkage often at the lower end and transverse shrinkage at the upper end. A tool that tolerates 0.5% shrink in a non-flame-retarded ABS but was cut without the 0.1 mm to 0.2 mm additional steel for the FR grade can produce undersized parts. The interaction between mould shrinkage and burn performance is not described by a single temperature correction factor; parts with thicker bosses and ribs can act as thermal mass that alters the vertical burn behaviour of the surrounding thin wall.

Property Data Obtained Under Standardised Laboratory Conditions

The values in the table are laboratory typical values and do not constitute a certificate of analysis. Lot-to-lot variation can occur because the flame-retardant package is added in a compounding step after raw ABS polymerisation. For production lots, the melt flow rate is commonly controlled within ±2 g/10 min around the nominal, and notched impact is typically monitored with a minimum of 5 specimens per batch under ISO 180:2023. The tensile and flexural data are generated on dry, single-gate injection-moulded specimens conditioned at 23 °C and 50% relative humidity for at least 24 h. If the material is moulded wet or with more than 20% regrind, impact and surface appearance can fall below the ranges shown. Published data for this specific configuration is limited beyond the supplier technical datasheet; independent qualification on the production tool and with the actual regrind ratio remains the only reliable verification method.

Regrind ratios up to 20 wt% are normally acceptable for non-appearance parts when the regrind is dry, homogeneous, and not thermally degraded. Higher ratios can shift the UL 94 rating because the flame-retardant package may degrade during previous moulding cycles. Recycled material should be re-dried at 80 °C for 2 h and should not be mixed with general-purpose ABS unless the target flame classification is re-tested. The melt should not be blended with amine-containing colour concentrates or additives because amine chemistry can accelerate degradation of halogenated flame-retardant systems and reduce moulding stability. Masterbatch carrier resins must be ABS or a fully compatible styrenic, and the total let-down ratio should not exceed 2 wt% unless trial mouldings confirm retention of mechanical properties.

Bags should be stored in a dry, covered area at ambient temperature below 35 °C, and opened bags should be consumed within 24 h or resealed. If condensation is observed on pellet surfaces, the material should be re-dried before processing. The material is not designed for outdoor exposure without UV-stabilised capstock or coating; ABS embrittles under prolonged ultraviolet radiation, and flame-retardant grades may show faster surface yellowing than unfilled ABS. No specific weatherability classification under UL 746C should be assumed without outdoor or xenon-arc data.

FRABS318-V0 should not be used in contact with food unless the specific grade is certified under FDA 21 CFR or EU 10/2011; flame-retardant ABS is generally not a food-contact candidate. The material should not be exposed to strong oxidising acids, ketones, esters, or chlorinated solvents; these cause stress cracking in ABS. For medical device housings requiring ISO 10993-1:2018 biocompatibility, a formulation-specific evaluation is mandatory because the flame-retardant package can contain extractable low-molecular-weight species. The grade is not recommended for continuous service above 85 °C without thermal ageing validation, because the heat deflection temperature under 1.8 MPa is only 78–84 °C and long-term exposure above this value may cause dimensional creep and progressive loss of impact.

For electrical enclosure applications, the material is usually specified with a glow-wire requirement from IEC 60695-2-11. A UL 94 V-0 rating at 1.5 mm does not automatically establish glow-wire ignition temperature in the finished part, because metal inserts, wall thickness, and air gaps alter heat transfer. Testing should be conducted on final mouldings at the thinnest wall and at the lowest specified thickness in the presence of any metal inserts. When the end-use standard requires a glow-wire flammability index of 850 °C at 1.5 mm, a separate IEC 60695-2-12 test is required. For unattended appliances where the final assembly must meet IEC 60335-1 clause 30, the material alone cannot certify the product; the complete enclosure and internal wiring must be evaluated.