Foreign material (FM) is a leading source of CAPAs, rework and rejects at Class III medical device manufacturing facilities.
For manufacturing lines that employ polyurethanes, silicones, dip casting, sewing, hydrophilic coatings, epoxy operations, solvent bonding, cutting, deburring and complex assembly protocols, FM is often the leading cause of defects.
While there are many types of FM (which will be covered in future articles), dark-colored particulate matter, due to its visibility, ranks very high as a defect category and is a leading cause for non conformance reports and CAPA’s. For Class III devices such as IOLs, cosmetic implants, neurological micro catheters, hydrophilic catheters, access devices and other cardiovascular devices, dark particle contamination alone generates defect rates in excess of 10%. In addition, related rework rates can easily exceed 30%.
Due to the severity of FM related issues, many Class III device manufacturers have implemented corrective actions that turn out to be ineffective because the source of the contamination was not properly identified.
Given the costs associated with open CAPAs, FM recurrence and nonconforming product, Class III device manufacturers need robust FM identification methods so that science-based root cause solutions can be developed.
SEM/EDX (Scanning electron microscopy with energy dispersive X-ray spectrometry) and FTIR (Fourier-transform infrared spectroscopy) are powerful analytical tools that are widely used to identify particulate contamination. Impeding the use of these tools in medical device manufacturing is the need to sample large and diverse surfaces. While many device manufacturers have used SEM/EDX and FTIR to identify contamination on components, backtracking to the source of the contamination has been far more difficult.
To leverage the power of SEM/EDX and FTIR to close CAPAs it is not enough to collect samples from the device. To be thorough, an investigation must tie the contamination on the device to the process and offending material. Because dark particulates have a wide variety of sources, it is a must to sample all related tooling and fixtures such as hand tools, automation, RF and ultrasonic welding dies, bonding tools, work surfaces and even floors, in order to perform a thorough investigation. Proper sampling involves collecting FM from both large surfaces as well as recessed areas of tools. The use of traditional SEM stubs requires a trained technician and is very expensive and time-consuming which has limited the appeal of this very powerful analytical method.
To assist Quality Engineers in developing root cause CAPA’s for dark particulate FM, Foamtec offers PolyCK wipers and swabs which are low cost and easy to use sample collection tools and combines this with SEM/EDX and FTIR analytical services to better solve vexing FM issues.
The following case study illustrates how contamination can be identified and eliminated. In this case rust colored FM was observed on devices, hand tools and gloves.
- Hand tools used to cut the device was sampled with the PolyCK swab
Area of the Tool that was Sampled
- Red particulate was visible on the PolyCK swab
- The swab was pressed against a SEM stub
- The SEM Stub was presented to the SEM/EDX instrument
- The red particulate was identified as an organic and metallic particles
- Using FTIR the organic red particulate was identified as uncured Loctite residue that had transferred to the cutting tool from in an upstream process
Since Loctite is not used in the factory upstream suppliers are being audited and cleaning practices are being reviewed.
Foamtec’s low cost and easy to use surface sampling tools combined with a material science lab in an ISO 5 cleanroom have enabled Quality Engineers to develop root cause solutions to vexing FM contamination issues.
To learn how to identify and reduce sources of FM please click here for more information.