Nanjing Delong PC/ABS CS107 is a melt-compounded alloy of polycarbonate and acrylonitrile-butadiene-styrene. The CS107 suffix is a supplier internal grade marker; it does not map to a published ISO 1043-1:2011 or ISO 11469:2016 designator in the consulted public documentation. Because complete lot-specific data for CS107 have not been posted by the manufacturer in a publicly accessible datasheet, the following paragraphs separate class-typical PC/ABS behaviour from supplier-specific quality verification. Where numerical values are provided, they represent the normal engineering envelope of unfilled general-purpose PC/ABS alloys, not a guaranteed CS107 certificate value. Incoming resin should be released only against a lot certificate that states the supplier’s measured values for melt volume-flow rate, tensile properties, impact energy, and heat deflection temperature under the test methods listed below.

What drying and melt-residence boundaries govern CS107 processing stability?

Because polycarbonate hydrolysis at melt temperature follows an autocatalytic chain scission path, moisture content must be certified below 0.02 wt% before plastication. Desiccant dryers for PC/ABS are typically set to 80 °C–100 °C with a dew point of −40 °C or lower. Drying time of 3 h–4 h is common for cold-start material; regrind additions above 20 wt% may require an additional hour if the regrind has been stored at ambient conditions. Moisture re-uptake becomes measurable in less than 30 min when pellet surfaces are exposed to air above 60 % RH, which is why closed conveying and feed-throat nitrogen blankets are used in high-humidity production environments. The melt-temperature window for unfilled PC/ABS is typically 240 °C–280 °C; barrel profiles of 230 °C rear, 240 °C middle, 250 °C front, and 260 °C nozzle are common. Residence time beyond 8 min at 280 °C is associated with brown-streak defect generation and loss of notched impact energy. On a 110-tonne injection moulding machine equipped with a 40 mm screw, class-typical PC/ABS is processed with injection velocities of 50 mm/s–120 mm/s; short-shot correction should prioritise melt temperature and venting over excessive boost pressure because the latter increases frozen-in stress.

Mould temperature is not a secondary variable in PC/ABS processing. With a mould-surface temperature below 60 °C, the skin layer quenches before sufficient packing, reducing weld-line strength and surface gloss. At 70 °C–100 °C, the same unfilled grade can exhibit a ductile failure mode in a notched Charpy test, but the transition also depends on notch preparation according to ISO 179-1/1eA:2010 and on specimen conditioning to 23 °C/50 % RH under ISO 291:2008. Production-scale studies on PC/ABS report decreases in Charpy notched impact energy of 15 %–30 % when mould temperature is reduced from 80 °C to 50 °C, without corresponding changes in tensile yield stress. This divergence means that tensile-only quality control can miss a substantial ductility loss. For CS107, if the supplier certificate does not state mould-temperature sensitivity, the processor should establish a two-point moulding trial at 60 °C and 90 °C and compare ISO 179-1/1eA impact energy on identical cavities.

Mechanical test protocols and property retention thresholds

Incoming inspection of Nanjing Delong PC/ABS CS107 should be built around specimen preparation in accordance with ISO 294-1:2017 and conditioning under ISO 291:2008. The table below is not a CS107 datasheet; it is a class-typical PC/ABS envelope used to detect whether a supplied lot falls outside normal alloy behaviour. Lot-specific limits must be taken from the supplier certificate or an agreed procurement specification.

For snap-fit geometries, the relevant design allowables are not tensile yield stress alone; flexural modulus and the strain rate dependence of yield stress must be considered. Rapid loading at 1 m/s can raise the apparent yield stress of PC/ABS by 10 %–25 % relative to a quasi-static ISO 527 test. Snap-fit strain should therefore be limited to below the supplier-confirmed strain at yield, and prototypes should be exercised at the lowest service temperature because PC/ABS exhibits a ductile-to-brittle transition that shifts upward with notch sharpness and paint solvents.

Electronic enclosure programmes that require glow-wire performance at 750 °C on contact parts are typically verified to IEC 60695-2-11:2021; unfilled PC/ABS can pass or fail this test depending on thickness and colour, so CS107 cannot be declared compliant without a thickness-specific test report. Automotive interior trim applications are screened under ISO 3795:1989 or FMVSS 302 for burn rate, but CS107-specific flammability classification should be confirmed at the exact part thickness. Candidate applications include interior brackets, appliance housings, and non-load-bearing electronic frames where the combination of dimensional stability and low-temperature impact is required. Applications involving continuous immersion in hot water above 80 °C are not suitable for standard PC/ABS because hydrolysis accelerates with temperature and retained stress.

Thermal degradation and moisture uptake are coupled failure modes.

In melt processing, thermal degradation of polycarbonate in PC/ABS proceeds through hydrolysis and transesterification reactions. Hydrolysis is accelerated by moisture above 0.02 wt%, while thermal chain scission becomes significant above 300 °C. In compounding, co-rotating twin-screw extruders with L/D 32:1–40:1 and vacuum vent pressure below −0.08 MPa are used to remove volatiles; in injection moulding, the same alloy is processed on general-purpose screws with L/D 20:1–24:1. The combination of high mould temperature and high melt temperature can generate splay and silver streaks; therefore, melt temperature and moisture cannot be optimised independently. Periodic moisture checks by ISO 15512:2019 Karl Fischer titration or a calibrated moisture analyser are necessary when the material is stored in unsealed bulk containers. If CS107 is reground after a previous moulding cycle, the regrind fraction should be limited to 20 wt% unless the supplier’s certificate permits a higher fraction, because repeated extrusion lowers the elongation at break and notched impact retention.

In comparison with general-purpose ABS, the polycarbonate segment in PC/ABS raises heat deflection temperature and low-temperature impact resistance. For example, the class-typical HDT at 1.8 MPa for unfilled PC/ABS is 95 °C–125 °C, whereas many ABS grades fall below 100 °C. This comparison is not a CS107 specification. Against PC/PBT alloys, PC/ABS grades typically retain higher notched impact at −30 °C but exhibit lower resistance to aromatic hydrocarbons, brake fluids, and hot alkaline cleaners. A conversion from PC/PBT to CS107 therefore requires immersion testing according to ISO 175:2010 or ISO 2812-1:2018 with the actual service fluid. Compared with high-flow PC/ABS grades having MVR above 25 cm³/10 min at 260 °C/5 kg, a lower-flow grade in the CS107 series, if it falls in the 8 cm³/10 min–15 cm³/10 min band, will require higher injection pressure and may be less suitable for thin-wall parts below 1.0 mm. The exact MVR and spiral-flow length for CS107 must be taken from the supplier certificate.

Compliance documentation for Nanjing Delong PC/ABS CS107 must be evaluated on the homogeneous material, not on the moulded assembly. The table below lists common regulatory checks for PC/ABS compounds used in electrical and automotive parts; the absence of a check in the table does not imply non-applicability.

The supplier’s certificate of analysis should be aligned to the procurement specification and include melt volume-flow rate, tensile yield stress, notched impact, HDT, density, and colourimetric data. A batch-to-batch control chart of ISO 1133-1:2022 MVR is a sensitive indicator of regrind content and molecular weight drift. If CS107 is supplied as a custom colour-matched grade, the effect of the colour concentrate on MFR and notched impact must be re-evaluated because pigment carriers can alter the ABS phase viscosity. Storage in sealed bags at 15 °C–30 °C away from direct sunlight is adequate; outdoor storage or exposure to repeated condensation cycles requires re-drying before processing. The absence of a public CS107 datasheet means that the first production lot should be qualified through a short-run moulding trial with dimensional capability analysis and mechanical testing on the actual part, not only on ISO test specimens.