Crastin® SK605LM BK591

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Crastin® SK605LM BK591 is a 30% Glass Reinforced, Laser Markable, Polybutylene Terephthalate

This material data has been provided by Matmatch.

All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.

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23.0 °C

1.52 g/cm³

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ISO 1183



Elastic modulus

23.0 °C

9.5 GPa

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ISO 527-1/-2


23.0 °C

2.5 %

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ISO 527-1/-2

Flexural strength

23.0 °C

200 MPa

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ISO 178

Impact strength, Charpy notched

23.0 °C

10 kJ/m²

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ISO 179/1eA

Impact strength, Charpy unnotched

23.0 °C

70 kJ/m²

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ISO 179/1eU

Poisson's ratio

23.0 °C

0.34 [-]

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Tensile strength

23.0 °C

130 MPa

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ISO 527-1/-2



Heat deflection temperature, 1.80 MPa

205 °C

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ISO 75-1/-2

Melting point

225 °C

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ISO 11357-1/-3 | 18°F/min


Burning Behav. at 60mil nom. thickn.: HB class, Thickness tested: 1.5 mm, Burning Behav. at thickness h: HB class, Thickness tested: 0.75 mm, Oxygen index: 20 %, Glow Wire Flammability Index, 30mil: 725 °C, Glow Wire Flammability Index, 60mil: 725 °C, Glow Wire Flammability Index, 120mil: 825 °C, Glow Wire Ignition Temperature, 30mil: 750 °C, Glow Wire Ignition Temperature, 60mil: 750 °C, Glow Wire Ignition Temperature, 120mil: 800 °C, FMVSS Class: B -, Burning rate, Thickness 1 mm: 54 mm/min

Rheological Properties


Melt volume-flow rate

5 cm³/10min

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ISO 1133


23.0 °C

0.3 %

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ISO 294-4, 2577

Shrinkage, transverse

23.0 °C

1.1 %

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ISO 294-4, 2577

Technological properties


30% Glass Fiber

Processing methods

Drying Recommended: yes, Drying Temperature: 120°C, Drying Time, Dehumidified Dryer: 2-4h, Processing Moisture Content: ≤0.04%, Melt Temperature Optimum: 250°C, Min. melt temperature: 240°C, Max. melt temperature: 260°C, Mold Temperature Optimum: 80°C, Min. mold temperature: 30°C, Max. mold temperature: 130°C, Hold pressure range: ≥60MPa, Hold pressure time: 3s/mm, Back pressure: As low as possible, Ejection temperature: 170°C