Learn how Nel PreTech used industrial CT scanning and dimensional analysis to identify molded part warpage and help optimize injection mold tooling for improved dimensional accuracy and reduced tuning time.
A tooling manufacturer approached Nel PreTech with a dimensional problem involving a molded plastic gear approximately 2 inches tall and 1 inch in diameter. The gear contains a center hole formed by a steel core pin during the injection molding process.
Inspection revealed that the hole exceeded the specified tolerance. At first glance, the solution appeared straightforward: reduce the diameter of the steel pin to create a smaller hole.
However, the dimensional issue was not caused by the pin itself.
The part was deforming as it cooled.
To achieve a dimensionally correct finished part, the tooling had to compensate for the predictable shrinkage and warpage occurring after molding.
As molten plastic cools, it shrinks. Depending on the material, wall thickness, and cooling rate, this shrinkage is rarely uniform.
Instead of remaining perfectly cylindrical, the center hole gradually distorted into an hourglass shape.
Simply machining the core pin smaller would not solve the problem because the finished geometry changes after the molding process is complete.
Instead, the tooling needed intentional dimensional compensation—commonly called building windage—so the molded part would shrink into the correct geometry.
Traditional metrology methods cannot fully evaluate an enclosed internal feature like this center hole without sectioning the part.
Industrial computed tomography (CT) scanning provided a complete, nondestructive view of both the external and internal geometry.
The scan produced millions of highly accurate X, Y, and Z coordinate points describing the entire component.
Engineers then compared the measured data to the nominal CAD model to calculate the exact deviation at every location.
The CT scan data was exported into engineering analysis software, where mathematical calculations determined the direction and magnitude of every dimensional deviation.
Those deviations were then inverted to create a compensated geometry for the tooling.
In this case, instead of using a perfectly cylindrical core pin, the analysis indicated that a subtle whiskey-barrel profile would produce the desired cylindrical hole after the plastic cooled and shrank.
These adjustments were extremely small—often only fractions of a millimeter—but they significantly reduced the trial-and-error normally required during mold tuning.
Although engineering calculations drive the process, experienced tooling engineers also apply practical manufacturing knowledge when determining the final compensation.
By combining industrial CT scanning with advanced dimensional analysis, Nel PreTech helped the customer:
For manufacturers producing precision molded components, industrial CT scanning provides the data needed to make informed tooling decisions before additional production cycles.
Industrial CT scanning is especially valuable when manufacturers need to:
Yes. CT scanning captures both internal and external geometry, allowing engineers to compare the molded part directly to CAD and identify where shrinkage or deformation has occurred.
Building windage is the intentional modification of mold geometry to compensate for predictable material shrinkage and warpage so the finished part meets dimensional requirements.
Unlike tactile probes or optical inspection systems, industrial CT scanning measures internal and external features simultaneously without cutting or damaging the part.
Yes. Nel PreTech provides industrial CT scanning and dimensional inspection data that customers can use to support tooling optimization, mold tuning, and engineering analysis. Inspection can be performed to customer drawings, CAD models, or applicable industry standards, depending on project requirements.
Dimensional problems in injection-molded parts are not always caused by the tooling itself. Material shrinkage, cooling behavior, and part geometry can all influence the final dimensions.
Industrial CT scanning gives manufacturers a complete view of how a part behaves after molding, making it possible to identify deformation, quantify dimensional changes, and support more effective tooling compensation.
If you're troubleshooting molded part warpage, optimizing mold tooling, or validating complex internal features, Nel PreTech's industrial CT scanning and dimensional inspection services provide the data needed to make confident engineering decisions while reducing development time and costly trial-and-error.
Talk to an Engineer to discuss your application or request a quote for industrial CT scanning and dimensional inspection services.
Victoria is the Creative Marketing Manager at Nel PreTech Corporation. She takes complex topics, like industrial CT scanning and 3D engineering, and turns them into accessible content for engineers and decision-makers. With a strategic communication background, she's helped Nel PreTech become a go-to partner in precision measurement and digital manufacturing. Off the clock, you’ll probably find her on a snowboard or hunting down the best tacos in town. She's not afraid to carve her own path!
You'll find all the detailed service information you need in one brochure.
Download Brochure
Get a quote within 24-hours and keep your project on schedule.
Get a Quote
Our Nel PreTech engineers are ready to get started on your product challenges.
Ask an Engineer
Download the ultimate CT Scanning Buyer's Guide to improve understanding, time, and efficiency in your scanning needs. Over 50 Pages of useful data and case studies.
Download Now
