Liquidity

The fluidity of SUMIKAEXCEL PES improves significantly with increasing cylinder temperature, injection pressure and molded product thickness. On the other hand, the effect of mold temperature is not so great. If mold release problems, glass fiber protrusions or weld cracks occur, we recommend raising the mold temperature to 160°C or higher.

Melt Viscosity Characteristics

The apparent melt viscosity of SUMIKAEXCEL PES is as follows:

General Molding

This article focuses on the flow characteristics at a wall thickness of 3 mm.

Effect of cylinder temperature

Increasing the cylinder temperature reduces the melt viscosity of the resin and improves its fluidity. Setting the cylinder temperature 20°C higher increases the bar flow length by 30 to 60%.

Figure 4-2-3 Temperature dependence of barflow length

Effect of injection pressure

By setting the injection pressure 20MPa higher, the bar flow length will improve by 10 to 20%. Generally, high pressure molding is recommended, but care must be taken to prevent mold release problems and residual stress caused by overfilling. Furthermore, the appropriate conditions are selected by setting the secondary pressure.

Figure 4-2-4 Dependence of bar flow length on injection pressure (4100G)

Effect of injection speed

The injection speed does not have a significant effect on the bar flow length.

Figure 4-2-5 Dependence of bar flow length on injection speed (4100G)

Effect of product thickness

The flow length increases rapidly with wall thickness. For wall thicknesses of 1.5 mm or more, a 0.5 mm increase in wall thickness increases the flow length by 40 to 70%.

Figure 4-2-6 Effect of wall thickness on bar flow length (4100G)

Thin-wall molding

This section describes the flow characteristics of molded products with wall thicknesses of 0.1 to 0.7 mm.

Effect of cylinder temperature

Increasing the cylinder temperature improves fluidity, but the effect is small for wall thicknesses of 0.3 mm or less. Taking into account the effects of retention, a temperature of up to about 380°C is appropriate.

Effect of product thickness

Please note that fluidity depends on the wall thickness when designing your product.

Effect of injection pressure

Thin-wall flow is relatively greatly affected by injection pressure. We recommend an injection pressure of 100 MPa or more, but please determine the appropriate pressure taking into consideration the product appearance and residual stress.

Effect of injection speed

Thin wall fluidity is not affected much by the injection speed. If the injection speed is too high, it may cause defects such as burning.

Effect of mold temperature

Thin-wall flow is not affected much by the mold temperature. However, if mold release problems, glass fiber protrusions, or weld cracks occur, we recommend setting the mold temperature to 160°C or higher.