Optical Inspection of Cut Pieces of Hypo and Precision Tubes

Germany-based developer of specialist optical control systems for plastic and rubber extruded products Pixargus—a spin off from the Institute of Plastics Processing (Institut für Kunststoffverarbeitung—IKV) of the Technical University RWTH of Aachen in Germany—is promoting its new ProfilControl 6-FFI system at Medtec Europe on February 26-28, 2013.

The ProfilControl 6-FFI system is used to inspect cut pieces of hypo and precision tubes for medical applications, which have to comply with extremely exacting surface and edge quality demands.

The press release announcing the news is published below.

The system is used for 100 percent inspection of hypo and precision tubes used in medical instruments and apparatuses as well as for cannulas made of metal and plastics. The system detects and classifies surface defects, such as inclusions, grooves, scratches or dents, over the complete product length. Furthermore, by means of a newly developed algorithm it checks whether the edges have been properly cut and/or feature no burrs. This ensures that only products completely checked and free of flaws are shipped.

With the development of the new system, Pixargus has bridged the gap between optical inspection of endless and cut products. So far the systems of the ProfilControl 6 series had only been used to inspect continuously manufactured products such as sections or cables. As the new systems can also inspect individual cut pieces, it can be used not only in the manufacturing process but also by the purchasers of the products for checking incoming material.

In order to make sure that the tubes are checked around their complete circumference from several angles all at the same time, the feeding system is provided with a gap. While the tubes are flying through this gap, their surface can be captured by the cameras from all perspectives.

Inside the measuring head, the surface of the tubes is uniformly illuminated by an LED light ring and scanned by six high-resolution line-scan cameras arranged at angles of 60° around the tube. With these six line-scan cameras of more than 2,500 pixels each, the system detects surface defects down to 30 µm.

As soon as the system has detected a defect on the surface or at one of the cut edges, the system displays the defect graphically and sends a signal to the device that will sort out the defective material. The PC 6-FFI system operates so fast that defective tubing can be removed just a few centimeters after the measuring head. This makes the system extremely space-saving.

PC 6-FFI features an automatic lighting control system, which automatically adjusts to mat or shiny surfaces.

Pixargus supplied the first such system to a Japanese customer who has been using it in three-shift operation since its commissioning. It had been designed for inspecting mirror-finished tubes of diameters between 5 and 20 mm and lengths between 40 and 100 mm.