An excellent article from Dean Solberg on the increased benefits of CT Scanning for industry, published in Quality Magazine.
Until recently, the technology of CT imaging was only available for use in medical settings. Over the last several years, industrial CT scanning has found a new home in the world of manufacturing, and is opening up myriad opportunities never before available.
CT Scanning, or computed tomography, is now commonly used in various industrial metrology settings, both in the lab and online or inline for product evaluation and packaging integrity assessment.
The main advantage is that it allows the inspection of a part’s interior structure or a package’s closure functionality without causing any harm or destruction to the objects themselves.
Industrial CT scanning utilises the same type of technology as CT scanners in hospitals and doctors’ offices—taking multiple readings from various angles and converting the CT grey scale images into voxel-based 3-D point clouds. Once the CT scanner generates the point cloud, a specialist can generate a CAD-to-part comparison map, construct a 3D model of the part, or reverse engineer the part to suit their needs.
Industrial CT scanning offers a multitude of advantages, such as:
• obtaining internal structure of an object non-destructively.
• validating extremely accurate internal dimensions.
• allowing comparison to reference models.
• compatibility with all shapes and sizes.
• no post-processing work and extremely high-resolution imaging.
Most common uses of 3D and CT scanning:
- Reverse engineering — the process of taking measurements of an existing part or object, then creating an exact CAD replica. This technology is extremely useful, when you have a manufactured part or object, but not the original prints or design data.
- Non-contact measurement — the process of capturing the geometry of existing objects through the use of laser emitting camera-like 3-D scanners.
- Contact measurement — a method of collecting single points relative to each other. There is a wide range of solutions for contact measurement and generally two types of systems solutions are used with portable CMMs: 1) For capturing localised or small volume information, digitising or articulating arms are used, 2) For larger volumetric projects, optical solutions including laser trackers and photogrammetry units.
- Long range scanning — for a detailed 360° 3-D snapshot of a structure, bridge, plot of land, plant or process operation with millimetre accuracy.
- Art forgeries — a bit unusual for what is thought to be an industrial product, but hundreds of art museums, dealers and auction houses use scanning each year to validate works of art, as well as the structural integrity of sculpture, for example.
- Model to manufacture processing — here again, artists will often have their models, whether fashioned or human, scanned for dimension prior to casting a statue in bronze or producing a high-fashion line of clothing.
Industrial CT scanning devices and long-range scanners serve a wide range of industries, and help assure that they are performing the highest level of testing and accuracy possible. A few of the diverse industries currently using this technology and the goals sought are:
• Manufacturing — for internal inspection of components and to ensure that a part meets specifications; this includes injection moulded, cast, forged or fabricated parts made from metal, plastic, polymers, composites and even 3-D printed products
• Power generation/nuclear — can scan the complex, hard to reach and hazardous areas of a nuclear power plant or conventional power generation facility for pipe alignment, boiler integrity, containment building stability and more
• Medical — devices and equipment, implants, orthotics and prosthetics; a one-off knee joint, for example, can be accurately compared to the original CAD program as well as the doctor’s MRI for accuracy
• Automotive and aerospace — allows engineers to do virtual testing of machinery, helps understand failures, works as a research & development tool to analyse structure, simulate reactions
• Arts — in the detection of forgeries and sculpture integrity
• Metal castings — to check for air bubbles and overall porosity
• Foods — to examine contents and packaging integrity
• Plastics industry — to inspect quality, wall-thickness and porosity analysis
• Mouldmaking — provides a powerful inspection and measurement tool to validate precise injection moulds and check structural integrity of a part.
The future of industrial scanning holds unlimited possibilities, especially when combined with 3-D printing or other additive manufacturing methods. As improvements are made in technology and performance and costs continue to decrease, the industrial scanning industry is preparing for explosive growth in the next 5-10 years.
