For measurement, testing and inspection in plastics processing, there are many technologies that make up the modern metrology toolbox. Each technology has its own features, characteristics, and strengths. For example, tactile coordinate measuring machines (CMMs) have long been a dependable and repeatable method of collecting accurate measurements where the probe touches the object's surface to gather data. A full range of accuracies are available in CMMs with several providing submicron accuracy. Non-contact optical structured light 3D scanners are another option that provide fast and accurate 3D digitalization of the entire object. The accuracy of structured light 3D scanners can also range, but single-digit one-to-two-micron accuracy can be achieved with smaller measuring volumes. The science behind the technologies is different; however, both collect coordinate measurement data and are widely used within the plastics industry. The question of when to consider using structured light 3D scanning is addressed by considering the application, its challenges and the required outcome.
Though contact metrology is the traditional methodology used for measurement, structured light 3D scanners also work in conjunction with tactile CMMs as a complementary enhancement in this process because of the 3D digitalization capabilities they provide to resolve common challenges plastics manufacturers face. Some of these challenges include increasing throughput, overcoming blind spots in data analysis, reducing the number of correction loops, lack of skilled workers, managing costs and materials in a tightened supply chain, controlling process variations, and monitoring the health of tooling to avoid unplanned downtime. For example, an automotive plastics tier-one supplier increased the number of parts scanned per year by more than 20 times after implementing structured light 3D scanning. Another automotive original equipment manufacturer (OEM) of air filter components reduced tool tuning iterations of plastic injection molding parts from 3-4 to 1-2 using structured light 3D scanning technology.