The Fastest Route to the Perfect Tool

The quality of plastic parts manufactured using plastic injection molding depends on many influencing factors: from the injection mold itself, the various process parameters to the type of plastic used. For example: the shrinkage behavior influences the dimensions of the injection molded part. Shrinking, in turn, depends on the other aforementioned influencing variables and cannot be predicted with great accuracy. The quality of the injection molding tool cannot be assessed by a simple measurement. Whether or not an injection mold will provide good results can only be determined by inspecting the parts manufactured using it.

Due to the difficulty in predicting the quality of an injection mold process, tools must often be reworked multiple times until the molded parts meet the quality standards. The components must be measured completely and exactly in every correction loop, and the molding tool must then be modified inline with these results. The challenges when performing any correction loop are:

• capturing as many evenly distributed and exact measuring points as possible
• transferring the measuring results to the CAD data of the tool shape
• ensuring an accurate fit for integrating the corrected segments into the overall shape

ZEISS offers coordinated solutions to ensure the entire tool correction process is efficient. This begins with determining dimensional stability using a ZEISS METROTOM computertomograph, which captures all internal and external structures of the component completely. In contrast to other standard processes where the component is actually dissected and the individual segments are measured, computed tomography offers important benefits:

• The inspection process does not destroy the component.
• The amount of time required is drastically reduced.
• The process is reliable: there is no risk of deforming within the scope of the inspection process.

The amount of information provided is greater because the entire component is captured, and not just individual sections. This can significantly reduce the number of correction loops required. The CT systems from ZEISS are also highly accurate and the results are traceable.

With ZEISS REVERSE ENGINEERING software, the CAD model of the injection molding tool can be corrected using the nominal data of a plastic component and the actual-data generated using the ZEISS METROTOM. The software corrects defective component segments in the tool dataset and ensures that the selected segments fit appropriately. ZEISS REVERSE ENGINEERING detects the underlying geometries using CT volume data. The mathematically calculated surfaces are then merged to create a watertight model, meaning that there are ideally no gaps or overlaps between the surfaces. Stipulated continuity conditions can be guaranteed extremely conveniently and reliably using ZEISS REVERSE ENGINEERING.