The first step in the mold development process—responding to a request for proposal (RFP)—requires moldmakers to import, diagnose and repair part geometry in order to assess its suitability for injection molding, develop estimates and produce a formal quote. Because moldmakers need to complete this step before even winning the business,

it behooves them to accomplish this as quickly and cost-effectively as possible by using a 3-D CAD system with broad model import and geometry manipulation capabilities. Of course, the best scenario is to use the specific CAD package that most of the moldmaker’s customers use to design parts, so the mold designer can simply open the file. However, because customer parts can range from 2-D drawings and neutral file formats—such as DXF™, DWG, IGES, STEP, ACIS® and Parasolid®—to file formats that are native to specific 3-D CAD systems, using a CAD platform that can import the widest set of diverse data formats directly, or through file conversions, provides a real advantage.

Whenever a mold designer imports plastic part data, he or she will inevitably encounter model geometry that includes errors, especially when converting or translating files. While a CAD system that can automatically diagnose and repair these errors is a real plus, mold designers will frequently need to repair some models manually. In these cases, using a CAD system that offers feature recognition tools for imported geometry can be a big help.

In addition to offering capabilities for diagnosing imported geometry in states of disrepair, CAD systems that include tools for repairing geometry errors have become increasingly beneficial. For example, mold designers need the ability to remove rounds and re-trim edges after removing rounds, especially when adding draft to improperly drafted parts.

Moldmakers also may encounter complex model geometry with gaps in surfaces, for which they will need advanced surfacing capabilities, such as an n-sided surface patch, which allows mold designers to fill in a surface tangent to a space defined by any number of boundaries, or the ability to pull on a point in a network of curves to modify a surface. At minimum, mold designers need access to round, draft and surfacing capabilities (e.g., sweep, loft, etc.) to handle imported models of varying degrees of complexity more efficiently.