Accessing Cost-Effective & Accurate Measurement and Validation

Accessing Cost-Effective & Accurate Measurement and Validation

There is an age old saying in manufacturing, that if you can’t measure it, you can’t make it. Such a sweeping statement may or may not be strictly correct when applied across industry in general, but when it comes to precise, feature-rich, complex plastic parts, it is absolutely right!

Measurement and validation in manufacturing is a subject in itself, and has attracted a  great deal of attention, and a number of technology-led solutions that industry has been using for many decades. As time moves on, these technologies develop and evolve, but essentially, manufacturers have had a somewhat restricted palette of options when it comes to measurement and validation.

That is until recently, as a new and groundbreaking measurement and validation solution has begun to gain momentum, namely CGI’s 3D cross sectional scanning technology. Here for the first time is a technology that can provide 100% accurate measurement of the internal and external geometries of intricate plastic parts or assemblies speedily, and above all cost-effectively.

Using CGI’s scanning technology, the part to be measured is encased in a slow-curing plastic resin, and the “set” block containing the part is then placed into the machine which slices it into 32 to 64 micron layers depending upon precise part geometry. As each layer is removed, an optical scanner captures a picture of the 2D profile, and once the entire block is consumed, all the 2D images are processed to produce a 100% accurate 3D point cloud model of internal and external geometries. This data can then be inspected.

The 3D scanner enables verification of CAD design intent and deviation, and makes a significant contribution to the design and manufacture of accurate and functional parts in a way that also allows for adherence to strict time-to-market requirements. Complete part validation can be completed in a matter of a few days.

A key reason for the uptake of CGIs technology is that it requires a much reduced operator skill level when compared to some alternative technologies, making the measurement and validation process quick and inexpensive. There is no need for dedicated staff as would be the case using CMM or CT technologies.

The 3D scanning technology uses Spec.CheckTM  proprietary software to cross-section parts anywhere and measure geometry, and the use of measurement templates allows for simple and repeatable checks of parts from multi-cavity tools, or indeed parts from different production batches. Measurements are accurate and repeatable.

Differentiators – CT Scanning, CMM, and Other Scanners

3D cross-sectional scanning offers some distinct advantages over alternative measuring and validation technologies, the key differences being focused on automation, completeness of the data set, and the materials that can be scanned.

CGI’s 3D cross-sectional scanning technology combines many of the benefits of contact and non-contact measuring systems, and extends the value by delivering complete part definitions in an automated process. In addition, with batch processing and templates, the process is extremely fast when performing inspection on multiple parts.

With the exception of more expensive and more complex CT scanners (typically 10 times the cost of the 3D scanning technology and requiring significant user skills), cross-sectional scanning is the only process that generates 100% accurate 3D data measurement of internal geometry or “inaccessible” features. While many OEMs have adopted protocols that find a way around the necessity to measure so accurately, CGI’s 3D scanning technology allows for the full inspection of a component to provide a thorough analysis of the quality of the part, both inside and out.

When compared to CMMs, cross-sectional scanning offers some real benefits in the areas of preparation and supplemental quality inquiries. To prepare for a CMM inspection, a thorough inspection plan is required. In effect, all features of interest and potential trouble spots must be defined prior to measurement of the object since it is not an easy matter to re-inspect a part. Building the inspection plan takes time and careful consideration. It also demands that the OEM is able to predict the elements that may affect part quality and performance.

Prior to inspection, the part must also be fixtured to position it for the CMM and to minimise variables that may corrupt the measurements. Also, the CMM must be programmed to capture each point of interest. This consumes a lot of employee time. With cross-sectional scanning, a rough inspection plan is all that is needed, since the dense point cloud allows unlimited quality interrogations without the need to rescan the part, and the process does not require fixturing or programming. This expedites the process and reduces the time demands on the inspection staff — with some OEMs reporting 10:1 labour savings.

Unlike laser and white light scanners, cross-sectional scanning does not use triangulation to calculate spatial data. This overcomes many of the limitations of these technologies. Cross-sectional scanning can handle a wide range of materials, including opaque and transparent, and has little limitation of part colour. Cross-sectional scanning can also inspect parts with either glossy or matte surface finishes.

What separates CGI from other 3D scanning technologies is the completeness of the 3D data sets. As opposed to laser and white light technologies, the CGI technology captures sharp corners, deep pockets, and internal geometry in a single scan. Use of CGI eliminates time-consuming post-process assembling of the data to create a complete data set.

Data can also be exported to 3D colour mapping software which allows for instant comparison of manufactured part geometry with original 3D CAD files.

CGI’s cross sectional scanning technology is now available to buy or to access through a bureau service from Plastic IT. We would suggest that the best way to experience the exceptional benefits of the technology are to see results from real-time products, so we look forward to working with you to show the possibilities that are now available to you as you measure and validate your plastic products.

For more information or for a quote, contact Richard Webster today at Plastic-IT on t. +44(0)7472 327166 or e.