Assembly Plastic Molding¶

Cost impact for upgrades to aPriori Professional 2021 R1

Cost Model Version Summary¶

The following table shows the cost model version numbers for the last three major releases:

Release	Cost Model Version	Status
aPriori 2021 R1	10	New with this release
aPriori2020 R1	5 (20.1.0) / 0 (20.1.1)	From a prior release
aPriori 2019 R2	N/A	N/A

Summary of Platform Changes¶

The table below indicates whether there were geometry and/or cost engine changes for this process group. Such changes could impact costing results for configured Digital Factories.

Platform Area	Was there a Change?
Geometry	Yes
Cost Engine	No

Change Summary by Area¶

The table below indicates which types of changes there were for this process group. For the first type of change (geometry or cost engine changes), the table indicates the impact level (High, Medium, Low, or No).

Area	Impact?
Geometry or cost engine changes that could impact configured Digital Factories	LOW (can be disabled)
Bug fixes or small improvements to prior cost model versions that could Impact configured Digital Factories	NO
Cost model changes that do not affect configured Digital Factories	YES

Details: 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.

Minimum Wall Thickness (Potential Impact: DTC Issues and Cooling Time): this release improves the determination of a part’s minimum wall thickness. Due to this enhancement, the value of the geometric property Min Thickness may increase by up to 5% for some parts. In addition, the value of the geometric property Average Wall Thickness and the calculated value Nominal Wall Thickness may increase very slightly. Some wall thickness issues raised by Design to Cost in the previous release may no longer be flagged. In addition, in rare cases, colling times may increase very slightly.
Void Extraction (Potential Impact: Tooling Cost): This release modifies the extraction of Voids (which represent undercut geometry) in order to improve the estimation of costs for side actions. For parts with multiple adjacent undercuts, tooling cost may change slightly due to changes in the number, type, and/or size of the part’s side actions. Tooling cost changed for fewer than 6% of parts in a test set.

Details: 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

Details: 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 (Potential Impact: Cooling Time and Machine Selection): This release improves the estimation of nominal wall thickness (which drives cooling time and can affect machine selection) by better taking into account the part’s aspect ratio and the degree of variation in the part’s thickness as well as the part’s aspect ratio.

In a large set of test parts, the following average changes were observed:
- Parts with a high amount of thickness variation:
  
  Nominal Wall Thickness decreased by 29%. Cooling Time decreased by 45.2%.
- Parts with a medium amount of thickness deviation (but not a high aspect ratio):
  
  Nominal wall thickness decreased by 22.0%. Cooling time decreased by 35.6%. Parts with a low amount of thickness variation (but not a high aspect ratio): Nominal wall thickness decreased by 11.6%. Cooling time decreased by 18.4%.
- Parts with a high height-to-length aspect ratio (but not high thickness variation):
  
  Nominal wall thickness decreased by 5.2%. Cooling time decreased by 6.8%. Cooling times increased for certain unusual parts with a high degree of thickness variation. In many cases, required clamp force increases somewhat due to this improvement, compared to the previous release. In rare cases, this can cause selection of a larger machine with higher overhead cost. !!! note "Note:"
  
  This change occurs for a given part only if the part’s GCDs are extracted in aPriori 2021 R1. For scenarios created in earlier releases and opened in aPriori 2021 R1, nominal wall thickness remains unchanged until GCDs are re-extracted.
Required Clamp Force (Potential Impact: Machine Selection): In previous releases, aPriori underestimated the machine clamp force required for a given part when a cold runner system was used, and it overestimated the clamp force required when a hot runner system was used. This release corrects the problem.

In a set of test parts, required clamp force increased on average by 33% for cold-runner systems, compared to the previous release. It increased on average by 11% for hot runner systems. The size of the change was greatest for parts with a high amount of variation in thickness and for parts made with structural foam molding. With cold runner systems, these changes can cause selection of a higher-force machine with higher overhead costs. With hot runner systems, these changes can cause selection of a lower-force machine with lower overhead costs.
Cup-shaped Parts (Potential Impact: Tooling Cost): With cup-shaped or arched parts (such as housings, covers, or bottle lids), aPriori previously underestimated the thickness of the core plate (or core block, in the case of pocketed inserts). In addition, for such parts, aPriori previously underestimated machining time for the cavity plate. This release improves these estimates. In a set of cup-shaped test parts, tooling cost increases ranged from less than 1% to 8%.

Note:

This change occurs for a given part only if the part’s GCDs are extracted in aPriori 2021 R1. For scenarios created in earlier releases and opened in aPriori 2021 R1, the change does not take effect until GCDs are re-extracted.
Mold Finished Area (Potential Impact: Tooling Cost): aPriori previously underestimated the mold surface area that required finish machining. This release improves the estimate. Estimated surface finishing area and costs decrease for simple parts but increase for more complex parts, compared to the previous release of aPriori. In a set of test parts, changes ranged from -4% to +1%.

Note:

This change occurs for a given part only if the part’s GCDs are extracted in aPriori 2021 R1. For scenarios created in earlier releases and opened in aPriori 2021 R1, the change does not take effect until GCDs are re-extracted.
Mold Inserts (Potential Impact: Tooling Cost): Previously, aPriori underestimated costs associated with machining the mold cavities into inserts rather than directly into the A and B plates. This release improves these estimates. In a set of test parts, tooling costs increased by an average of around 3% when standard mold bases were used and around 4% when custom mold bases were used.
Weight-based Mold Costs (Potential Impact: Tooling Cost): Previously, aPriori overestimated weight-based mold costs such as import duty, freight, heat treatment, stress relief, and plating, because the estimates were based on starting (pre-machined) mold mass rather than finished (post-machined) mold mass. This release corrects the problem. As a result, weight-based tooling costs decrease slightly compared to the previous release.
Tool Machining (Potential Impact: Tooling Cost): Previously, aPriori underestimated total manufacturing rate (an aggregate of labor and overhead rates) for tool machining. This release improves this estimate, which now better reflects the type of milling process (3-, 4-, or 5-axis mill) required for the tool by the part’s geometry.

As a result, machining rates applied when calculating tooling costs increase by 22% on average, compared to the previous release. The increase varies by geographic region of the tool shop Digital Factory. (Note that tool manufacturing costs also may change further due to the other enhancements described earlier in this section.)
Hot Runner Plate Thickness (Potential Impact: Machine Overhead and Cycle Time): This release reduces the default plate thickness for hot runner systems. As a result, aPriori may now select a smaller machine with lower overhead costs. Cycle times may change as a result, but tooling cost is not affected. Note that users can override the default plate thickness with the new setup option Hot Drop Plate Thickness.