Dongguan Baoli PC/ABS MC1300 is a polycarbonate/acrylonitrile-butadiene-styrene alloy supplied in pellet form for injection moulding. The grade is positioned for thin-wall electronic housings, power adapter shells, router enclosures, and automotive interior trim where a reduction in melt viscosity relative to general-purpose PC/ABS is required while retaining notched Izod impact strength above 20 kJ/m² at 23 °C according to ISO 180:2023. Because the manufacturer has not posted a publicly archived English-language datasheet for this exact grade, the following engineering data are compiled from typical high-flow PC/ABS formulations and should be verified against the current certificate of analysis for each lot. The suffix 1300 is supplier-specific and does not denote a standardized ISO grade designation. The material is commonly described as a high-flow, non-flame-retardant PC/ABS with a balance of heat resistance, impact strength, and processability, but final compliance and property limits remain subject to the supplier’s lot release document.

Material Design and Property Profile of MC1300

The design of MC1300 is governed by the phase morphology and compatibilization between polycarbonate and ABS. In PC/ABS alloys, the polycarbonate contributes thermal stability and impact strength, while the ABS phase improves melt processability and lowers cost relative to neat polycarbonate. High-flow grades such as MC1300 are typically produced by raising the ABS fraction or selecting a lower-viscosity polycarbonate. The consequence is a measurable shift in the property balance: heat deflection temperature and low-temperature impact are slightly reduced, while spiral flow length and thin-wall filling capacity increase. Representative values for this grade class are listed in Table 1. These values are not guaranteed minima; they serve as preliminary engineering references for mould filling simulations and material selection.

Production-scale compounding of MC1300 on a co-rotating twin-screw extruder with L/D 40 is used to disperse the ABS phase and compatibilizer. The polycarbonate phase is usually fed at the main throat, while the ABS phase may be side-fed downstream to limit exposure to high melt temperatures. Screw speeds of 400–700 rpm and melt temperatures of 260–290 °C are common, with vacuum devolatilization at -0.08 MPa to remove residual volatiles. If the melt temperature exceeds 300 °C, the polycarbonate phase undergoes chain scission, visible as yellowing and a drop in notched Izod impact. The compounded strands are water-bath cooled and pelletized under conditions that keep moisture uptake below 0.03% before packaging. The pellets require sealed aluminum-lined bags for long-term storage in tropical climates.

Pre-drying of MC1300 is not optional under shop-floor conditions where the open-container storage period exceeds 4 h or the ambient relative humidity exceeds 60%. Polycarbonate segments in the alloy are susceptible to hydrolysis during plastication if residual moisture is above 0.02% by weight. The standard drying method is a desiccant dryer operating at a dew point of -40 °C or lower, with an inlet air temperature of 80–100 °C and residence time of 3–4 h. For cold or humid warehouses, the residence time should be extended to 4–6 h. Hot-air tray dryers are generally inadequate because they cannot maintain the required dew point; the resulting moisture content can remain above 0.05%, producing silver streaks on part surfaces.

Regrind usage is acceptable only when the regrind is kept free of dust and moisture. The recommended maximum regrind fraction is 20–25 wt% for unpainted parts. Higher regrind levels can shift the melt mass-flow rate upward and reduce notched Izod impact because repeated extrusion degrades the polycarbonate molecular weight. A melt flow rate check according to ISO 1133-1:2022 at 260 °C/5 kg before and after regrind addition is a practical batch-control method; an increase greater than 15% relative to virgin pellets indicates excessive thermal history.

Why Does Drying History Control Surface Appearance in Thin-Wall Moulding?

The effect of drying history on MC1300 surface appearance is not merely cosmetic. Residual moisture attacks carbonate linkages in the polycarbonate phase during the high-shear plastication stage. At a melt temperature near 260 °C, the hydrolysis reaction reduces molecular weight and generates carbon dioxide and phenolic by-products. In a thin-wall cavity with nominal wall stock below 1.2 mm, the melt front often advances under fill speeds above 100 mm/s; any reduction in molecular weight produces a lower-pressure drop for the same flow length, but also an unstable melt front temperature. The resulting defects include gate blush, splay, and flow hesitation marks. When moisture exceeds 0.03%, cavitation may occur at the screw check ring, leading to shot-weight variation greater than 0.5% on production-scale equipment. Published data for this specific configuration is limited, but the mechanisms are well established in PC/ABS processing literature and are used to set the 0.02% moisture specification.

Recommended injection moulding parameters for MC1300 on a standard reciprocating-screw machine are as follows: rear zone 230–250 °C, middle zone 240–260 °C, front zone 250–270 °C, nozzle 250–270 °C; mould temperature 60–80 °C; injection velocity 50–150 mm/s; holding pressure 60–100 MPa; screw back pressure 3–7 MPa; and screw speed 40–80 rpm. A shut-off nozzle is required when the nozzle temperature exceeds 260 °C because the material’s low melt viscosity can cause drooling. For hot-runner tools, valve-gate systems are preferred over open-tip hot runners, and the hot-runner manifold temperature should not exceed 280 °C for residence times beyond 10 min. The processing window is narrower than that of a medium-flow PC/ABS. If the mould temperature is below 50 °C, weld-line impact strength drops sharply; if the melt temperature exceeds 280 °C, the ABS phase begins to yellow and the polycarbonate phase is subject to thermal decomposition. The material should be purged from the barrel after 30 min of uninterrupted idle time to avoid black specks and carbonized residue.

Rheologically, MC1300 is pseudoplastic. At processing shear rates from 100 to 5,000 s⁻¹, apparent viscosity decreases by approximately 60–70% relative to the zero-shear value. The power-law index in the 240–270 °C range is typically between 0.30 and 0.50, indicating significant shear thinning. This property enables filling of long flow paths but also means that small changes in injection speed have a large effect on cavity pressure. Mould-filling simulation should use Cross-WLF viscosity coefficients measured on the specific lot; generic PC/ABS data can underestimate pressure drop by 10–15% in thin-wall tools. The thermal conductivity of the alloy is approximately 0.2 W/m·K, which limits cooling rate and should be considered when quoting cycle time reductions.

Weld-line strength in MC1300 is sensitive to melt front temperature and mould venting. When two flow fronts meet at a temperature below 140 °C, the PC and ABS phases do not fully interdiffuse, and notched Izod impact can drop by 40–50% relative to the bulk material. To maintain weld-line impact above 15 kJ/m², mould temperature should be held at the upper end of the 60–80 °C range, and vents of 0.02–0.03 mm depth should be placed at the last-fill location. For multi-gated parts, sequential valve gating is preferred because it reduces the number of weld lines and keeps the flow front moving.

When Melt Viscosity Is Reduced Without Sacrificing UL 94 Compliance

MC1300 is typically a non-flame-retardant alloy. Under UL 94 testing at 1.5 mm, unfilled PC/ABS grades of this type usually receive an HB classification. A V-0, V-1, or 5VA rating is not implied by the base resin and must be confirmed for the exact color, thickness, and regrind content through the supplier’s UL yellow card. This distinction matters when comparing MC1300 with flame-retardant PC/ABS formulations that use phosphate-ester additives. The phosphate-ester FR grades achieve ignition resistance but sacrifice heat deflection temperature by approximately 10–20 °C and notched impact strength by 20–30% relative to non-FR grades of similar flow. In addition, phosphate-ester FR grades can leave acidic by-products in the mould that require more frequent tool cleaning. In contrast, MC1300 is selected for non-FR applications where processing ease and impact strength take precedence over ignition resistance. The base resin may be assessed under RoHS Directive 2011/65/EU and REACH SVHC obligations, but the final compliance statement must cover the specific color concentrate and additive package used in production.

Comparative Positioning Against Lower-Flow and Higher-Flow PC/ABS Grades

Relative to a general-purpose PC/ABS with a melt mass-flow rate of 8–12 g/10 min at 260 °C/5 kg, MC1300 reduces peak injection pressure by about 15–25% in a 1.0 mm wall section, depending on runner diameter and gate geometry. The flow increase is achieved through molecular-weight selection and phase-ratio adjustment, not through external lubricants. The trade-off is a heat deflection temperature that is typically 5–10 °C lower and a notched Izod impact at -30 °C that may be 10–20% lower than that of a lower-flow, high-impact PC/ABS. Compared with a super-high-flow PC/ABS with a melt mass-flow rate above 30 g/10 min, MC1300 generally retains better weld-line strength and improved chemical stress-cracking resistance because the ABS fraction is not as high. However, MC1300 is not intended for thick-wall structural parts above 3.5 mm, where the high-flow melt can exhibit jetting and uneven packing unless gate size and injection speed are specifically controlled.

When MC1300 is compared with neat polycarbonate, the key differences are processability and chemical resistance. Neat polycarbonate has a melt mass-flow rate of 6–12 g/10 min at 300 °C/1.2 kg and requires higher melt and mould temperatures, while MC1300 can fill similar thin-wall parts at lower injection pressures. Neat polycarbonate has superior transparency and higher heat deflection temperature, but it is more prone to stress cracking in aliphatic hydrocarbons and has a higher melt viscosity. Compared with neat ABS, MC1300 provides higher heat resistance and notched impact strength but is more susceptible to hydrolysis and alkaline cleaning agents. These differences determine material selection when a part must pass a drop test at -20 °C while being moulded on a 1,200 kN clamp machine.

Solvent stress cracking resistance of MC1300 follows the PC/ABS pattern: short-term exposure to dilute acids, salt solutions, and aliphatic hydrocarbons at 23 °C for 24 h produces no significant loss in tensile yield stress when measured according to ISO 527-2:2012. Aromatic hydrocarbons, chlorinated solvents, ketones, and concentrated oxidizing acids can craze the surface and reduce notched impact strength by more than 30%. Strong alkaline solutions above 60 °C are particularly aggressive because they hydrolyze the polycarbonate phase. The material is not classified for continuous use in direct contact with automotive brake fluid or strong organic acids. For UV-exposed exterior parts, carbon black or a UV stabilizer package is required; unpainted natural resin will exhibit gloss loss and chalking under outdoor exposure, with the rate dependent on total solar irradiance but often visible within 12–24 months.

Applications commonly cited in supplier technical literature for MC1300 include power adapter housings, router enclosures, electronic control unit covers, and interior automotive trim. These applications typically involve wall stocks of 1.0–2.5 mm, notched Izod impact requirements above 20 kJ/m² at 23 °C, and moulding machines with clamp forces between 800 and 1,600 kN. The grade is not recommended for load-bearing under-hood components exposed to continuous temperatures above 100 °C, nor for food-contact articles unless a specific regulatory certification has been issued for the exact pigment lot. Any substitution of MC1300 into an existing PC/ABS tool should be preceded by a short-shot study because the lower melt viscosity shifts gate freeze time and requires re-optimization of holding pressure and switch-over point.