Moldability

Apparent Melt Viscosity

Figure 4-2-1 and 4-2-2 show the shear rate dependence and temperature dependence of the apparent melt viscosity of SUMIKASUPER LCP, respectively. Compared to other engineering plastics, the apparent melt viscosity of SUMIKASUPER LCP is greatly affected by both the shear rate and temperature. Therefore, moldability depends greatly on the injection speed, cylinder temperature, and shear heat generated during injection molding. The low viscosity and high shear rate dependence of SUMIKASUPER LCP make high-speed injection molding possible since the pressure does not easily increase even at high injection speed. Its viscosity becomes extremely low under proper injection molding conditions, making it easy to fill thin-walled or complicated-shaped products. On the other hand, for stable production, it is necessary to properly manage the injection speed and cylinder temperature, and to monitor changes in shear force caused by wear or other factors.

Figure 4-2-1 Shear Rate Dependence of Apparent Melt Viscosity

Figure 4-2-1 Shear Rate Dependence of Apparent Melt Viscosity

Figure 4-2-2 Temperature Dependence of Apparent Melt Viscosity

Figure 4-2-2 Temperature Dependence of Apparent Melt Viscosity

Thin-Wall Flowability

SUMIKASUPER LCP has excellent thin-wall flowability compared to other engineering plastics. Figure 4-2-4 shows the thin-wall flowability (thickness : 0.2, 0.3mm) of each grade, where flowability is measured using the tool shown in Figure 4-2-3, and Figure 4-2-5 shows the bar flow length with a thickness of 1mm.

Figure 4-2-3 Mold for Thin-Wall Flow Length Measurement (Unit : mm)

Figure 4-2-3 Mold for Thin-Wall Flow Length Measurement (Unit : mm)
Product thickness : 0.3mm
Runner : 4.0mmφ
Gate : 0.3t×1.5w×2.0L
Flow length is 4 cavities average
Product thickness : 0.2mm
Runner : 3.0mmφ
Gate : 0.2t×1.5w×2.0L
Flow length is 4 cavities average
Molding machine : PS10E1ASE (Nissei Plastic Industrial Co., Ltd.)
Injection pressure : 0.2mm thickness : 90MPa
0.3mm thickness : 60MPa
Injection speed : 0.2mm thickness : 95%
0.3mm thickness : 60%
Mold temperature : 130°C

Figure 4-2-4 Thin-Wall Flowability

Figure 4-2-4 Thin-Wall Flowability

Figure 4-2-5 Flowability of Various Engineering Plastics at 1mm Thickness

Figure 4-2-5 Flowability of Various Engineering Plastics at 1mm Thickness

Thin-Wall Flowability

The thin-wall flow length of SUMIKASUPER LCP depends on the molding conditions and mold shape. Figure 4-2-7 shows the results of thin-wall flow length evaluation for various grades molded at the same injection speed and pressure using the same mold as shown in Figure 4-2-6. SUMIKASUPER LCP has high flowability even a product thickness of 0.1mm, and a wide range of molding conditions can be applied, allowing it to be utilized in products of various shapes.

Thin wall flowability measurement conditions (0.10mm, 0.12mm, 0.15mm, 0.20mm, 0.30mm)

  • Injection molding machine : ROBOSHOT S-2000i30B (FANUC Corporation)
  • Resin temperature : Standard molding temperature
  • Mold temperature : 120˚C
  • Injection speed : 200mm/sec

Figure 4-2-6 Mold for Thin-Wall Flow Length Measurement

Figure 4-2-6 Mold for Thin-Wall Flow Length Measurement

Figure 4-2-7 Thin-Wall Flow Length

Figure 4-2-7 Thin-Wall Flow Length

Figure 4-2-8 Thickness Dependence of Thin-Wall Flow Length 1

Figure 4-2-8 Thickness Dependence of Thin-Wall Flow Length 1

Figure 4-2-9 Thickness Dependence of Thin-Wall Flow Length 2

Figure 4-2-9 Thickness Dependence of Thin-Wall Flow Length 2
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