Makrolon 2405 Pc – Low-viscosity Injection Molding Grade

In thin-wall injection molding and parts with long flow paths, filling consistency is often the bottleneck. Many molders find that standard polycarbonates run short or show flow marks, while high-MFR grades sacrifice the toughness that makes PC the material of choice. Makrolon® 2405 from Covestro resolves that trade-off. With an MVR of 19 cm³/10 min at 300°C/1.2 kg, this low-viscosity general-purpose PC delivers excellent cavity fill while retaining a notched impact strength of 65 kJ/m² at 23°C. It is the grade we routinely recommend for applications where dimensional precision, optical clarity, and production efficiency all matter simultaneously.

Product Specifications

Property	Test Condition	Value	Unit	Standard
Melt Volume-Flow Rate (MVR)	300°C / 1.2 kg	19	cm³/10min	ISO 1133
Melt Mass-Flow Rate (MFR)	300°C / 1.2 kg	20	g/10min	ISO 1133
Density	23°C	1200	kg/m³	ISO 1183-1
Tensile Modulus	1 mm/min	2400	MPa	ISO 527-1,-2
Yield Stress	50 mm/min	65	MPa	ISO 527-1,-2
Yield Strain	50 mm/min	6.0	%	ISO 527-1,-2
Strain at Break	50 mm/min	125	%	ISO 527-1,-2
Flexural Modulus	2 mm/min	2350	MPa	ISO 178
Flexural Strength	2 mm/min	97	MPa	ISO 178
Charpy Notched Impact Strength	23°C / 3mm	65	kJ/m²	ISO 179/1eA
Charpy Notched Impact Strength	-30°C / 3mm	14	kJ/m²	ISO 179/1eA
Heat Deflection Temperature	1.80 MPa	124	°C	ISO 75-1-2
Vicat Softening Temperature	50 N / 50°C/h	145	°C	ISO 306
Light Transmittance (clear grade)	1mm thickness	89	%	ISO 13468-2
Mold Shrinkage (parallel)	60x60x2 mm³ / 500 bar	0.65	%	ISO 294-4

Test specimens were conditioned at 23°C and 50% relative humidity unless otherwise noted. All values are typical and based on injection-molded samples.

Key Properties

Low Viscosity / High Flowability – MVR 19 means easier filling of thin ribs, long flow paths, and complex core geometry. One molder reported a 15-20% improvement in flow length compared to a standard medium-viscosity PC under identical clamp and melt settings.

Easy Release Formulation – Internal lubricants reduce adhesion to tool surfaces, minimizing ejection stress and cycle interruptions. This translates to fewer stuck parts and less post-mold finishing.

Optical Clarity with Low Haze – At 1 mm thickness, light transmittance is 89% with refractive index 1.586, and haze below 0.8% for 3 mm sections. This makes it suitable for lenses, covers, and light guides where visual fidelity matters.

Balanced Toughness Across Temperatures – Notched impact strength remains at 14 kJ/m² even at -30°C, so parts hold up in cold environments without becoming brittle.

Dimensional Stability – With mold shrinkage in the 0.5–0.7% range and equilibrium water absorption of just 0.12%, parts maintain tight tolerances even in humid service conditions.

Typical Applications

LED Luminaires and Lighting Components – A lighting OEM developing a portable work light needed high clarity plus impact resistance for a thin-walled diffuser housing. Makrolon 2405 filled the 0.8 mm wall section consistently while maintaining the optical uniformity required for light distribution.

Electrical Enclosures and Switchgear – A control device manufacturer chose this grade for relay covers and switch bezels, relying on its UL94 V-2 rating at 0.75 mm and stable dielectric properties across frequency ranges.

Automotive Interior Trim – A tier-two supplier producing decorative bezels and small instrument cluster parts leveraged the low-viscosity characteristics to mold fine surface details without sink marks, while the 125% elongation at break provided sufficient ductility for clip assembly.

Optical Lenses and Transparent Guards – A precision optics shop replaced a higher-viscosity PC with this grade for protective windows and sensor lenses, achieving better cavity fill in a multi-cavity tool and reducing reject rates by approximately 8% based on their internal tracking.

Technical Comparison

Parameter	Makrolon 2405	Typical Medium-Viscosity PC	Typical High-Flow PC
MVR (cm³/10min)	19	9–12	25–30
Tensile Modulus (MPa)	2400	2300–2400	2200–2300
Notched Impact Strength (kJ/m²)	65	65–70	50–60
HDT 1.8 MPa (°C)	124	125–130	120–125
Mold Shrinkage (%)	0.5–0.7	0.5–0.7	0.6–0.8

Makrolon 2405 occupies a practical middle zone—more flow than standard grades, better toughness than ultra-high-flow alternatives. For parts with long flow paths or thin cross-sections, it reduces short-shot risk without forcing a downgrade in mechanical performance.

Supply Chain and Logistics

Qingdao Prime Union Trade Co., Ltd. has operated in the engineering plastics distribution space for over two decades, maintaining direct authorized distribution agreements with Covestro, Chimei, SABIC, Hanwha Total, and Hyosung. Our portfolio also includes supply relationships with Mitsubishi, Rohm, and LG for complementary engineering thermoplastics.

This grade is readily available through our in-stock program, supported by four strategically located warehouses across China. We handle general trade, processing trade (including bonded manual operations), and bonded warehouse transactions, with full import/export clearance capabilities. For customers requiring color matching or property modification, our sister company Qingdao Primetech Plastics offers compounding services covering PC, ABS, PP, PA, PBT, PPS, PPA, and PETG. Modification directions include toughening, mineral/glass filling, alloying (PC/ABS, PC/PBT), flame retardancy, and custom coloring. Standard color developments and basic modifications carry a 3-day sample lead time, with production quantities typically ready within 7 working days. We also supply related polycarbonate grades across the Covestro portfolio and can assist with grade selection for your specific application.

Samples are fee-based, but the sample cost is credited against your first full container or truckload order.

Frequently Asked Questions

Q: What is the recommended melt temperature range for Makrolon 2405?
A: Melt temperature should be set between 280–320°C, with 300°C as a standard starting point. Mold temperature should be maintained between 80–120°C. Barrel settings, from rear to nozzle, are typically 250–260°C, 270–280°C, 280–290°C, and 290–300°C at the nozzle.

Q: Does this grade require drying prior to processing?
A: Yes. Polycarbonate is hygroscopic. Dry with dehumidified air at 120°C for 2–3 hours, and verify moisture content is ≤ 0.02% before molding to avoid hydrolytic degradation and splay marks.

Q: What color options are available for Makrolon 2405?
A: Covestro offers this grade in transparent, translucent, and opaque color formulations. The transparent variant delivers 89% light transmission at 1 mm thickness. For black automotive applications, the dedicated PC BLACK-MAKROLON AL2405 is available with optimized pigment dispersion and surface gloss.

Q: Does Makrolon 2405 carry UL and other certifications?
A: Yes. The grade is UL94 V-2 rated at 0.75 mm and 0.36 mm, and HB at 2.7 mm. It also meets Glow Wire test requirements (GWFI 850°C at 0.75 mm) and is listed with a Relative Temperature Index of 125°C for tensile strength and 115°C for tensile impact at 1.5 mm.

Q: What trade and logistics options do you support for international buyers?
A: We support general trade, processing trade with manual management, and bonded warehouse import/export. Our bonded facility in Qingdao allows for flexible inventory arrangements, and we coordinate with customs brokers to ensure smooth documentation for overseas shipments.

Q: Can you provide technical support for processing or material selection?
A: Yes. Through our sister company Qingdao Primetech, we offer material selection guidance, processing parameter recommendations (melt/mold temperatures, drying protocols, screw speed), and troubleshooting for common molding defects related to material behavior. For custom formulations—such as flame-retardant, toughened, or colored variants—we provide compounding services and color matching.

Makrolon 2405 delivers a practical balance of flow and toughness for thin-wall, complex, and optically demanding PC parts—supported by a supply chain built for consistency and trade flexibility.

Source: Covestro – Makrolon® 2405 Public Technical Data Sheet