Bayblend displays high impact and notched impact strength over a wide range of temperatures. The energy absorbed in the penetration test increases with higher polycarbonate contents.

Thermal properties

Depending on the field of application, moulded parts may be exposed to direct sunlight, engine heat and other temperature stresses. It is therefore essen-tial that the plastic parts used have a high heat resistance.

In terms of heat resistance, Bayblend covers virtually the entire range between ABS and polycarbonate. For instance, the standard Bayblend grades possess a heat deflection temperature of between 112 °C and 134 °C according to Vicat B 120, while the Bayblend FR grades offer products with Vicat temperatures between 87 °C and 136 °C.

The practical heat deflection temperature of Bayblend is higher than that of ABS at the same Vicat temperature. Consequently, depend-ing on the shape of the moulded part, the practical requirements and the processing conditions, the thermal stress can often be higher than the Vicat temperature without any significant dimensional changes occurring in the moulded part. The reason for this is the higher residual modulus at temperatures above the Vicat temperature, resulting from the fact that polycarbonate has a glass transition temperature of approx. 150 °C.

In the electrical sector, housings must not display unacceptable deformation as a result of the thermal stresses to which they are exposed. The heat resistance of customary Bayblend formulations in the ball indentation test (IEC 335-1) is between 75 °C and 125 °C, making them suitable for insulating housings. Some highly heatresistant grades achieve values >= 125 °C and can thus be used in direct contact with live parts.

The coefficient of linear thermal expansion is in the region of ABS and is somewhat higher than that of pure polycarbonate. Nonreinforced grades display slight dependence on the direction of meet flow. The values for glass fibre-reinforced grades are highly dependent on direction, based on the orientation of the glass fibres.

Electrical properties
Protection against accidental contact and reliable, durable insulation of live parts are key requirements. With a volume resistivity of > 1016 ohm, Bayblend meets the specifications as regards insulation resistance in the low-voltage range up to 4,000 V, as demonstrated by practical tests on actual moulded parts.

Optical properties
Bayblend is opaque on account of the rubber component. Therefore, only opaque colours are possible, and these are available in a host of shades. On smooth moulded parts, non-reinforced Bayblend generally produces uniform surfaces with high gloss. Surfaces with a lower degree of gloss can be achieved by treating the mould surface appropriately.