Properties of resin composites

The resin composite material contains glass fiber as a reinforcing material, so the physical properties are anisotropic due to the orientation of the glass fiber after injection molding.
We conducted a tensile test by cutting out a dumbbell-shaped specimen from a plate-shaped specimen actually created by injection molding from different angles.
The figure shows the result.
The mechanical properties are strongly influenced by the fiber orientation distribution.
We have improved the accuracy of structural analysis by using data that considers this fiber orientation distribution.

Creep property of plastics

Creep is the phenomenon that the material deforms slowly and irreversibly under constant mechanical stress.
The creep phenomenon is thus modeled with springs and dashpots.
Plastic has three stages of creep.
The primary stage involves significant deformation.
In the secondary stage, it is constantly deformed.
In the tertiary stage, the deformation is accelerated and finally breaks.