Injection mold
Optimizing Product Function-injection molding

The injection molding process affords many opportunities to enhance part functionality and reduce product cost.

The injection molding process affords many opportunities to enhance part functionality and reduce product cost. For example, the per-part mold costs associated with adding functional details to the part design are usually insignificant. Molds reproduce many features practically for free. Carefully review all aspects of your design with an eye toward optimization, including part and hardware consolidation, finishing considerations, and needed markings and logos, which are discussed in this section.

Consolidation

Within the constraints of good molding practice and practical mold construction, look for opportunities to reduce the number of parts in an assembly through part consolidation. A single molded part can often combine the functionality of two or more parts.

Hardware

Clever part design can often eliminate or reduce the need for hardware fasteners such as screws, nuts, washers, and spacers. Molded-in hinges can replace metal ones in many applications. Molded-in cable guides perform the same function as metal ones at virtually no added cost. Reducing hardware lessens material and assembly costs, and simplifies dismantling for recycling.

Finish

Consider specifying a molded-in color instead of paint. The cost savings could more than justify any increase in material cost for a colored material with the required exposure performance. If you must paint, select a plastic that paints easily, preferably one that does not require surface etching and/ or primer.

Markings and Logos

Secondary methods of adding directions, markings, and logos — including labels, decals, printing, stamping, etc. — add cost and labor. Molded-in techniques, when applied properly, produce permanent lettering and designs at a very low cost. Mixtures of gloss and texture can increase contrast for improved visibility.

Miscellaneous

Look for opportunities to add easily-molded features to simplify assembly and enhance product function such as aligning posts, nesting ribs, finger grips, guides, stops, stand-offs, hooks, clips, and access holes.