EP Tips: Purging

In injection molding, when switching from a previously molded resin to a new one, if residual old resin remains within the molding machine, it can lead to appearance defects such as cloudiness.

We recommend screw cleaning when switching resins. On the other hand, as a simpler switching method, Iupizeta EP allows for resin replacement through inter-grade purging. For some grades, replacement efficiency can be improved and the amount of resin required for purging can be reduced by replacing them via another grade rather than direct replacement.

The purging procedures for representative grades are shown in the diagram. Please contact us if you would like to know the purging procedures for other grades.

Example 1) When switching from EP-8000 to EP-6000
We recommend first replacing EP-8000 with EP-9000, and then switching to EP-6000.

Example 2) When switching from EP-4500 to EP-9000
We recommend first replacing EP-4500 with EP-6000, and then switching to EP-9000.