Check PET Preforms for CRYSTALLINITY and other defects.














Strain Viewer with special Alignment Stage removed.

This Sharples Strain Viewer is already in worldwide use for the quality control of PET preforms.

The advantages of our PET preform Strain Viewer are : -

   1.    Crystallinity is readily identified.

   2.    Not only can the molecular birefringent flow lines (fringes) be seen in colour           but the black isoclinic lines are visible when the preform axis are parallel to           the polarising axis of the viewer. The isoclinic lines indicate the directions of           the molecular orientational strains.

   3.    A special and removable stage is provided to rapidly obtain the correct           alignments of the preforms when viewing.
          For observations of the fringes the preforms are aligned at 45 degrees to
          the polarising axis and at 0 degrees to view the black isoclinics.
          The stage allows for the rotation of the preforms whilst viewing.


Sodium light is also provided, in addition to white light, for the examination of coloured preforms or completed bottles. The lamphouse is fan cooled.


Viewing field:..............260 x 260mm

Overall size:...............445 x 280 x 280mm

Mains voltage:............220/240v or 110v


Preform strain pattern


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