Covestro Makrolon® 6557 PC Resin
Makrolon 6557 PC Resin Flame retardant grades
Covestro Makrolon 6557 is a flame retardant, medium viscosity polycarbonate resin. Offering UL 94 V-0 rating at 3.0 mm, excellent UV stabilization for durability, easy mold release, and versatility in transparent, translucent, or opaque colors.
Associated Documents
ISO TDS
Typical property data
Physical Properties (Rheological)
- Melt Volume-Flow Rate (300 °C/1.2 kg): 10 cm³/10 min (ISO 1133)
- Molding Shrinkage (Parallel): 0.65% (ISO 294-4)
- Molding Shrinkage (Normal): 0.7% (ISO 294-4)
Mechanical Properties (23 °C/50 % r. h.)
- Tensile Modulus: 2400 MPa (ISO 527-1, -2)
- Yield Stress: 66 MPa (ISO 527-1, -2)
- Yield Strain: 6.1% (ISO 527-1, -2)
- Flexural Modulus: 2400 MPa (ISO 178)
- Flexural Strength: 99 MPa (ISO 178)
- Charpy Notched Impact Strength (23 °C, 3 mm): 70 kJ/m² (ISO 21305/ISO 179/1eA)
- Charpy Notched Impact Strength (-30 °C, 3 mm): 14 kJ/m² (ISO 21305/ISO 179/1eA)
Thermal Properties
- Glass Transition Temperature: 144 °C (ISO 11357-1, -2)
- Temperature of Deflection Under Load (1.80 MPa): 124 °C (ISO 75-1, -2)
- Vicat Softening Temperature (50 N, 50 °C/h): 143 °C (ISO 306)
- Burning Behavior (3.0 mm): UL 94 V-0 (UL 94)
Electrical Properties (23 °C/50 % r. h.)
- Relative Permittivity (1 MHz): 3.0 (IEC 60250)
- Volume Resistivity: 1×1014 Ω⋅m1 \times 10^{14}\ \Omega·m (IEC 62631-3-1)
- Electrical Strength (1 mm): 34 kV/mm (IEC 60243-1)
Other Properties (23 °C)
- Density: 1200 kg/m³ (ISO 1183-1)
- Water Absorption (Equilibrium Value at 23 °C, 50 % r. h.): 0.12% (ISO 62)
Processing and Drying Conditions
- Injection Molding – Melt Temperature: 280-320 °C (ISO 294)
- Injection Molding – Mold Temperature: 80-120 °C (ISO 294)
- Dry Air Drying Temperature: 120 °C
- Drying Time: 2-3 hours
- Moisture Content (Max.): ≤ 0.02%
Features & Benefits
Uncompromising Flame Safety
Makrolon pc 6557 achieves UL 94 V-0 at 3.0 mm thickness and a high Oxygen Index (36%), providing critical fire resistance for electrical and electronic components, enhancing end-product safety and meeting stringent regulations.
Enhanced Durability & Clarity
Built-in UV stabilization protects against yellowing and degradation from sunlight exposure, maintaining mechanical integrity and optical clarity (up to 89% transmittance @ 1mm) for demanding indoor and outdoor applications.
Optimized Processing Efficiency
Its medium viscosity and easy-release characteristics reduce mold fouling and sticking, enabling smoother injection molding cycles, faster production, and lower maintenance costs for manufacturers.
Use & Applications
- Electrical & Electronic Components: Switches, connectors, circuit breakers, fuse housings, terminal blocks, power supply enclosures.
- Automotive Interior & Underhood: Sensor housings, lighting components (non-optical), connectors, small covers.
- Consumer & Industrial Enclosures: Housings for power tools, small appliances, control units, safety equipment.
- Outdoor Equipment Housings: Covers for communication devices, meters, garden tools.