Many of the defect found in PET container performs can be detected by using the PL-2.Preforms viewed in polarized light exhibit a colored birefringence pattern.
The birefringence is a result of the polymer flow lines (molecular orientational strain) produced during the injection moulding process.
The colored pattern observed with perform held at 450 to the polarizing axis is known as isochromatic fringe indicating the amount of birefringence.
When the preform is held parallel to the polarizing axis a black isoclinic can be seen indicating the direction of molecular orientational strain.
By correctly interpreting these flow pattern many perform defects can be detected.
With angle adjusting design, operator can view perform as their most convenience angle. And with the upgraded wider viewer area and sample platform, more perform could be placed and viewed in the same time. It also frees the hands of operator.