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Plastic Molding

Geometry or Cost Engine Changes that Could Impact Configured Digital Factories

The following changes might impact costing, even for Digital Factories that use earlier cost model versions.

  • NO IMPACT

Bug Fixes or Small Improvements to Prior Cost Model Versions

The following changes might impact costing for Digital Factories that use earlier cost model versions.

  • NO IMPACT

Cost Model Changes that Do Not Affect Configured Digital Factories

The following changes do not affect costings with Digital Factories that use earlier cost model versions. The changes are available only in the latest cost model version.

  • Nominal Wall Thickness for Injection Molding (can impact cycle time, machine selection, overhead costs, and tooling cost): The previous release, aPriori 2023 R1, introduced a problem in the calculation of nominal wall thickness for Injection Molding parts. Some parts that should have been classified as High Aspect Ratio were instead erroneously classified as Low Thickness Deviation or Medium Thickness Deviation. The classification affects aPriori's estimate of nominal wall thickness, cool time, and required machine clamp force. This release fixes the problem and correctly classifies all parts. (The custom output Nominal Wall Thickness Profile indicates how a part is classified.)

    As a result of this change, estimated cool time increases for some parts now correctly classified as High Aspect Ratio, compared to the previous release. In a set of test parts, cool time generally increased by around 10% for parts classified as High Aspect Ratio, although increases of up to around 50% were observed. In rare cases, a higher-overhead machine might be selected for such a part. Tooling costs might also change slightly in some cases.

    The affected parts are those for which both the following conditions apply:

    • Part does not have high thickness variation. A part is considered to have a high amount of thickness variation if the geometric property Thickness Std Dev is greater than the value of the cost model variable medThicknessDevThreshold (0.50mm in starting point Digital Factories).
    • Part has a height-to-length ratio greater than or equal to the value of the cost model variable highAspectRatioThreshold (0.50 in starting point Digital Factories) and less than the value of the cost model variable cmHighAspectRatioThreshold (3.0 in starting point Digital Factories). (Note that part height is measured in the draw direction, for plastic molding process groups.) The problem affects only cost model version 220 (introduced in aPriori 2023 R1). Earlier cost model versions are not affected, unless they have been customized to import the library libFunctionsUtils.csl.