Complex / Tight Tolerance Injection Molding

Chassis for Hand-Held Medical Display

Intermediate Housing for Hand Held Ultrasound Device

Laboratory Test vial with 0.016” Dia. Through Hole


Engineers Inspecting Part Feature

Toolmaker Effecting Adjustments to Core & Cavity



Four Cavity Class 103 Injection Mold with Collapsing Air Cooled Slide Cores


Close / Tight Tolerance Injection Molding

Successfully producing highly accurate injection molded plastic components involves:

• A Highly Skilled Technical Team
• Optimized Tooling
• Accurate & Repeatable Molding Presses
• Inspection Capability

PILLER AIMMCO offers all of the above, in-house, and can point to a track record of successfully producing many very close tolerance components for clients in the medical, aerospace, automotive and consumer electronics industries.

Achievable part tolerances for injection moldings are influenced by a number of variables such as:
• Part Geometry
• Part Size
• Feature Locations
• Resin Type & Shrink Rate
• Tool Design
• Molding Process Control and Machine Repeatability

In general, consistency between parts is a product of process control, and assuming a stable process, optimized tooling, and low shrink material, part-to-part accuracy can be very consistent, within 0.001” for example, and can be held even tighter depending upon the mix of variables. Applications demanding higher levels of accuracy and precision will involve an iterative tooling approach to “dial-in” critical features. Flow modeling for warp prediction, optimized gate locations and cooling strategies are performed, and the tool is designed “steel safe” with part features on the low end of the tolerance.

Once the mold is designed and constructed, a thorough trial is performed to establish and center the molding process window, and to collect data that will allow an understanding of process drift and stability. Armed with this information, decisions can then be made regarding tooling adjustments, such as:

• Removing (or adding) tool steel to center a critical feature in the tolerance zone
• Gate revisions
• Cooling adjustments
• Adding or revising over-flow features
• Vent adjustments
• Cavity geometry “falsifications” to address unpredictable warp or feature size

For each round of adjustments, another molding trial is performed and the results evaluated until the tooling features and molding processes produce acceptable results. Given all of these complexities it is obvious that successfully producing close tolerance, complex injection molded components is anything but trivial. However, with our knowledge, technical team and integrated tooling and molding operations, we are uniquely accomplished at these activities, able to produce results where most others cannot.   Contact us to discuss the tolerance requirements on your critical project.

Complex Injection Molding

Successfully producing complex part geometries not only requires an intense focus on tooling strategy, but also leadership, collaboration, and a willingness to think outside the box. Experience matters, and having produced thousands of injection molds, PILLER AIMMCO offers this experience in spades. We routinely tool and produce parts that many of our competitors have said cannot be done. Following are a few examples:


Single Cavity Class 103 Injection Mold
with Four Slides and EJ Bar 

Two Cavity Class 103 Injection Mold
with Slides, Lifters & Extended EJ

The key to success in these challenging projects lies not only in expert tool engineering, but just as critically the ability to quickly affect mold changes based on the evaluation of results obtained from molding trials. The process boils down to iterative development with many of the same process steps described above for close tolerance parts. Our technical team understands the nuances with tooling and molding, and with our integrated operations we are able to effectively collaborate to find solutions and deliver results, while competitors tend to raise their hands in frustration and tap out. Contact us to discuss how we can help turn your complex part requirements into reality .

PILLER AIMMCO – We Plan, We Execute, We Deliver