Standard Guide for Assessing the Removal of Additive Manufacturing Residues in Medical Devices Fabricated by Powder Bed Fusion

Importancia y uso:

5.1 Materials used in medical devices are selected in part for their biocompatibility, meaning that they have been demonstrated to have an acceptable biological response for the intended application. During manufacturing, most devices are exposed to a variety of processing steps and materials that have the potential to adversely affect the inherent biocompatibility of the device if they are not adequately removed prior to use.

Note 1: For a fine powder, depending upon application, a new biological risk assessment may be required.

5.2 In additive manufacturing, components are in most cases built layer-by-layer, allowing unprecedented freedom to design complex devices. This makes it possible to build devices that are very difficult to clean, such as topological optimized parts, small internal channels, lattice structures, and especially reticulated porous structures for bone ingrowth and fixation.

5.3 Powdered fusion AM presents additional challenges. Components come out of the build volume with residual powder filling all open spaces within the device. The majority of the excess powder is typically removed by a combination of vibratory shaking, blowing with compressed gas, vacuuming, and ultrasonic cleaning in a solvent. However, the particles are typically very small and can become lodged in internal features such as pores, making removal difficult. Furthermore, particles that were immediately adjacent to the component during manufacturing can be partially sintered to the surface. Those particles can be extremely difficult to remove, are indistinguishable from loose particles when observed by most techniques, and may be at risk of detaching during the intended use of the device.

5.4 This guide provides specific evaluation techniques for measuring the effectiveness of residue removal processes, as they should be able to yield consistent results that meet the respective performance and cleanliness criteria for the intended use.

Subcomité:

F04.15

Volúmen:

13.02

Número ICS:

11.020.01 (Quality and environmental management in health care), 11.040.01 (Medical equipment in general)

Palabras clave:

device cleanliness; e-beam sintering; laser sintering; residual particles;