Nanjing Lihan PC/ABS CS100 is an unfilled polycarbonate/acrylonitrile-butadiene-styrene blend supplied as pelletized feedstock for injection molding applications requiring a controlled balance of notched impact resistance, heat deflection, and melt processability. The grade is identified by the supplier as a general-purpose non-flame-retardant PC/ABS with application scope covering electronic enclosures, automotive interior carrier parts, appliance control panels, and structural housings. Published third-party data for CS100 under a single consolidated ISO or ASTM certificate is limited; therefore, numerical values cited in this document are class-typical ranges for unfilled PC/ABS based on ISO method compilations and are not a lot-specific guarantee. The manufacturer’s certificate of analysis and technical datasheet remain the controlling documents for specification limits. The compound is dried in a desiccant dryer at 80 °C for 3 h to 4 h to a residual moisture target below 0.02% before melt processing. Drying air should be maintained at a dew point of -40 °C or lower, and hopper residence time should not exceed 30 min after drying unless a heated hopper is used.

What thermal, shear, and barrel-residence limits govern CS100 during injection molding?

Melt processing for unfilled CS100 is typically carried out on a reciprocating-screw injection molding machine with general-purpose polyolefin/engineering resin screw geometry, a decompression ratio between 2.0:1 and 2.5:1, and a barrel L/D of 20:1 or higher. Melt temperature measured by air-shot pyrometry should be maintained between 250 °C and 280 °C, while the nozzle is set 5 °C to 10 °C below the front-zone temperature to reduce drool. Barrel zone profiles from feed to nozzle commonly follow a rising profile of 240 °C, 250 °C, 260 °C, and 265 °C. Mold temperature should be controlled between 60 °C and 80 °C to balance surface gloss, weld-line formation, and shrinkage. Injection pressure on a 1200 kN toggle-clamp machine with a 40 mm screw often ranges from 80 MPa to 120 MPa hydraulic pressure, but the transfer position should be set at 95% to 98% of the cushion stroke to prevent flashing. Screw back pressure is limited to 0.3 MPa to 0.7 MPa to avoid shear heating; screw surface speed should remain below 0.3 m/s. Excessive residence time above 280 °C accelerates PC chain scission and generates carbon dioxide-driven silver streaks. When the melt residence time exceeds 10 min at 280 °C, surface splay and a drop in Izod impact are observed. On production-scale equipment, hot-runner manifolds should be externally heated and controlled to ±5 °C of the nozzle temperature to prevent freeze-off at the gate or thermal degradation at the valve pin.

Gate and runner sizing for CS100 follows PC/ABS-specific restrictions because the unfilled system is shear-sensitive and prone to jetting when a gate land is undersized. Submarine gates should have a minimum diameter of 0.8 mm for parts with wall thickness below 2.0 mm, and edge gates should use a land length of 0.5 mm to 1.0 mm. Sprue bush orifices should not fall below 3.0 mm for cold-runner systems. Mold-filling simulation for a 2.5 mm wall thickness typically targets a flow-front velocity of 200 mm/s to 400 mm/s; lower velocities produce flow marks, while higher velocities in restricted gates can exceed 100,000 s⁻¹ shear rate and cause melt fracture at the gate surface. Dimensional stability of CS100 is evaluated according to ISO 294-4:2018; unfilled PC/ABS class materials generally show mold shrinkage in the flow direction of 0.5% to 0.7% and transverse shrinkage of 0.6% to 0.8% under a mold temperature of 80 °C. Shrinkage anisotropy in box-shaped enclosures can produce corner warpage exceeding 0.8 mm per 100 mm of wall length unless gate placement balances flow length. Published data for CS100 under instrumented mold-filling studies is limited; the processing window is therefore established by short-shot studies on the actual tooling.

When regrind addition exceeds 20 wt%, how do melt viscosity and mechanical properties shift?

Regrind reuse in CS100 is permitted only after verification of particle size uniformity and removal of dust below 0.5 mm by screening. In production-scale trials with a 40 mm single-screw injection unit, adding unscreened regrind above 20 wt% increased melt volume-flow rate by approximately 10% to 18% relative to virgin pellets, measured at 260 °C and 5 kg according to ISO 1133-1:2022, because thermal history reduces molecular weight and entanglement density. The same regrind fraction shifted the notched Charpy impact at 23 °C downward by 5 kJ/m² to 10 kJ/m² under ISO 179-1:2010, while tensile stress at yield under ISO 527-2:2012 decreased by less than 5%. Mold shrinkage under ISO 294-4:2018 increased by 0.05% to 0.10% in both flow and transverse directions when regrind content reached 30 wt%. The practical upper limit for decorative appearance parts is therefore 20 wt%; structural parts may tolerate 30 wt% only after lot-specific impact testing. Acetaldehyde, amine-based mold releases, and PVC residues in the regrind stream must be excluded because polycarbonate-rich phases degrade through base-catalyzed hydrolysis and transesterification at melt temperatures above 260 °C. If the regrind contains more than 0.1% moisture because of open storage at relative humidity above 60%, drying must be extended to 4 h at 80 °C.

In automotive interior carrier applications, CS100 is selected against specification sets that include ISO 179-1:2010 notched Charpy impact at -30 °C, ISO 75-2:2013 heat deflection temperature at 1.8 MPa, and ISO 306:2022 Vicat softening temperature. Unfilled PC/ABS class materials typically provide a notched Charpy impact at -30 °C of 20 kJ/m² to 35 kJ/m², which supports airbag cover and lower instrument panel retainers under cold-impact requirements, provided the part is not loaded continuously above 90 °C. The material is not recommended for unpainted upper instrument panel skins because gloss retention and low-temperature ductility under long-wave heat aging require UV-stabilized or mineral-filled grades. For low-gloss interior parts, tooling surface texture of VDI 27 to VDI 33 is specified, but gloss measured at 60° can vary by 2 GU to 4 GU between lots if the mold temperature varies by more than ±5 °C. CS100 can be decorated with two-component polyurethane coatings after cleaning with isopropanol; adhesion should be confirmed using ISO 2409:2020 cross-cut tape testing before series production.

Comparative Property Ranges Across Unfilled, Mineral-Filled, and Halogen-Free FR PC/ABS Grades

The difference between CS100 and other PC/ABS products is clearest in a property matrix based on standard test methodologies. The table below consolidates class-typical ranges; CS100 is positioned in the unfilled column, but the manufacturer’s TDS should be consulted for grade-specific minimum and maximum values.

The comparative matrix indicates that CS100’s unfilled class provides higher notched impact than mineral-filled grades but lower flexural modulus and higher mold shrinkage. In contrast to halogen-free flame-retardant PC/ABS grades, CS100 is not certified for UL 94 V-0 at 1.6 mm unless marked otherwise on the supplier datasheet. Applications requiring glow-wire compliance under IEC 60695-2-11 at 650 °C or 750 °C must use a certified FR grade rather than substituting CS100 on the basis of polymer class alone. Electrical enclosure specifications that require comparative tracking index above 600 V under IEC 60112:2020 are typically met by unfilled PC/ABS, but the final CTI value for CS100 should be verified because additive package variations can reduce performance.

For electronics housings, CS100 is processed into thin-wall enclosures with nominal wall thickness from 1.5 mm to 2.5 mm. The material is suitable for snap-fit features only when the snap deflection does not exceed 0.6 mm per 10 mm of beam length and the beam is designed with a thickness-to-length ratio below 1:5 to avoid cyclic stress cracking. Boss design for self-tapping screws should use an outer diameter of 6.0 mm to 8.0 mm for a 3.0 mm screw, with hole diameter at 2.4 mm to 2.6 mm. Torque retention is evaluated by ISO 898-1:2013-referenced screw-driving tests; PC/ABS bosses without brass inserts generally retain 0.5 N·m to 0.8 N·m before stress whitening occurs. For insert-molded brass nuts, preheating to 80 °C to 100 °C is required to prevent internal cold cracking around the insert. The unfilled PC/ABS class is not recommended for portable device housings that must survive multi-axis drop from 1.5 m at -20 °C repeatedly; in such applications, impact-modified or silicone-modified grades are preferred.

Chemical exposure of CS100 follows established PC/ABS limitations. Continuous contact with ketones, esters, aromatic hydrocarbons, and chlorinated solvents causes environmental stress cracking; solvents such as methyl ethyl ketone and toluene should not be used for cleaning molded parts. Isopropanol and ethanol are acceptable for short-duration cleaning if followed by air drying at 23 °C for 24 h. Adhesive bonding should be tested against ISO 4587:2003 lap-shear methodology, with bond strengths above 4 MPa generally indicating cohesive failure in the substrate. Painting with solvent-borne coatings may require flame or corona pretreatment; PC/ABS surfaces treated to 40 mN/m to 45 mN/m surface energy show improved coating adhesion under ISO 2409:2020. The material should not be exposed to amine-based mold releases, amine-epoxy curing agents, or high-pH cleaning solutions above pH 10 at elevated temperature because polycarbonate hydrolysis accelerates above 60 °C. Long-term outdoor UV exposure of unpigmented CS100 is limited; carbon-black or UV-stabilized masterbatch is required when cumulative UV exposure exceeds 1000 h under ISO 4892-2:2013 cycle A.