Page 283 - Engineering Plastics Handbook

Liquid Crystal Polymer (LCP) 245

Figure 11.2 Typical SEM image
of tensile fractured as-spun fiber
of LCP.

conventional thermoplastics. Filled LCPs are, therefore, recommended
for injection molding (Fig. 11.3).
Filled LCPs offer the following advantages in properties compared to
the conventional engineering plastics:
1. Excellent processability that leads to short cycle time because of the
low heat of fusion and the high flowability even in thin sections due
to low melt viscosity under high shear
2. Little or no flash due to the low injection pressure and the shear sen-
sitivity of viscosity
3. High modulus due to the high oriented skin structure

2

1.5 PBT resin Transverse direction
(TD)
Mold shrinkage (%) 1 PBT resin Flow direction (FD) 70 mm square
(TD)

2 mmt
(FD)

0.5 Gate
LCP resin
(TD)

0
LCP resin
(FD)
0 10 20 30 40 50
Glass fiber content (wt%)
Figure 11.3 Mold shrinkage versus glass fiber content.