Mechanical Properties SUMIKASUPER LCP

Thickness dependence of moldings

The molecules of SUMIKASUPER LCP are easily oriented due to shearing forces at the time of melting. The thinner the walls of moldings, the greater the percentage of the skin layer. This skin layer has a very uniform molecular orientation, therefore providing greater relative strength per area of cross section. Table 1, Figure 1 and Figure 2 show the strength dependant on specimen thickness, for each type of SUMIKASUPER LCP.

Table 1 : Strength Dependant on Specimen Thickness

Property Thickness (mm) E5008L E5008 E4008 E6008 E6006L E6807LHF
Tensile Strength(MPa) 0.5 151 161 178 199 215 174
0.8 151 139 171 184 194 161
1.2 135 119 158 164 172 145
1.6 132 113 131 149 160 137
Tensile Elongation(%) 0.5 2.4 2.9 3.0 3.0 2.4 2.5
0.8 2.7 3.1 3.7 3.5 2.8 3.0
1.2 2.8 3.3 4.1 4.0 3.4 3.5
1.6 3.1 3.5 4.5 4.2 3.7 3.8
Tensile Modulus(GPa) 0.5 18.6 17.6 19.5 18.6 21.7 18.4
0.8 16.1 15.4 17.1 16.5 15.8 14.2
1.2 14.1 12.4 13.4 12.4 12.2 11.5
1.6 11.6 11.0 10.8 11.0 9.8 9.8
Molding Temperature(deg C) 400 380 350 340
Molding Machinery : PS40E5ASE, Nissei Plastic Industrial
Test Piece : No.1 (1/2), JIS K7113 Dumbbell piece

Figure 1 : Strength Dependant on Specimen Thickness

Figure 1 : Strength Dependant on Specimen Thickness

Figure 2 : Diagram of Skin / Core

Figure 2 : Diagram of Skin / Core

Anisotropy of Physical Properties

Table 2 shows the anisotropic characteristics of SUMIKASUPER LCP.
It is apparent that the values for the flow direction (MD) differ greatly from the values perpendicular to the flow direction (TD) (Table 2). Please ensure that the gates are positioned properly when designing molds used in the injection molding process.

Table 2 : Anisortopy of Physical Properties

Item Unit Measurement directon E5008L E5008 E4008 E6008 E6006L
Mold shrinkage % MD 0.05 0.06 0.10 0.18 0.19
% TD 0.81 1.25 1.32 1.16 0.74
Flexural strength MPa MD 137 130 138 136 156
MPa TD 58 56 57 61 92
Flexural modulus GPa MD 13.4 12.6 12.7 12.2 11.4
GPa TD 3.7 3.3 3.0 4.4 4.7
Molding : 64 x 64 x 3mmt 1mmt film gate
Test specimen : 13w x 3t x 64l mm
Span : 40mm
Injection molding Mchine : Nissei Jushi Kogyo PS40E5ASE type

Weld Strength

In general, liquid crystal polymers have high anisotropy and a rapid solidification speed, thus tend to have lower weld strength (Figure 3). The appropriate design is of critical importance when producing molds.

Figure 3 : Weld Strength of SUMIKASUPER LCP

Figure 3 : Weld Strength of SUMIKASUPER LCP

Temperature Dependence of the Flexural Modulus

The elastic modulus of liquid crystal polymers, such as SUMIKASUPER LCP, does not decrease at the glass transition point as greatly as that of crystalline or amorphous polymers. Rather, the elastic modulus tends to decrease gradually as the temperature rises. All of the SUMIKASUPER LCP series products possess effective flexural modulus, even at a temperature of 250 deg C, thus are ranked highest among all heat resistant engineering plastics (Figure 4). In addition, performing heat-treating of the moldings enhances the strength of their skin layers, thus improving the elastic modulus. Heat treatment also improves the overall strength, deformation temperature and creep resistant of moldings, in addition to the elastic modulus.

Figure 4 : Temperature Dependence of Flexural Modulus

Figure 4 : Temperature Dependence of Flexural Modulus

Recyclability

Mixing 30% recycled SUMIKASUPER LCP to virgin material, a slight degradation of overall strength can be observed in the initial few recycling periods. However, after being recycled for a third time, almost no changes are observed, and strength retention is over 90% (Figure 5). In addition, the value of shrinkage does not change significantly (Figure 6).
Please consult with us in the event that the usage of recycled products must be greater than 30%.

Figure 5 : Relation between Number of Repetition of Recycling and Retention of Tensile Strength

Figure 5 : Relation between Number of Repetition of Recycling and Retention of Tensile Strength

Figure 6 : Relation between Number of Repetition of Recycling and Mold Shrinkage

Figure 6 : Relation between Number of Repetition of Recycling and Mold Shrinkage
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