Ed Kangas, BMP Vice President, Sales and Marketing, came away impressed with the process. "It was an open, very collaborative discussion," he told PlasticsToday, adding that it involved a "deep, three-day dive into our processes that provided us with an opportunity to implement internal improvements." As the first injection molder to achieve MedAccred accreditation, pending approval, "it's a differentiating factor and gives smaller suppliers like us greater visibility."

By providing OEMs with oversight and verification of compliance to critical manufacturing process requirements, MedAccred enhances patient safety, says the organization. Suppliers benefit by improving their operations based on audit criteria while reducing the number of on-site customer audits. They can also benefit from exposure to existing and new customers, which, in the long term, strengthens relationships and creates new opportunities.

If all goes according to plan, BMP Medical (Gardner, MA) can claim a world first. It will soon be the first injection molding company to achieve accreditation from MedAccred (Warrendale, PA), a new medtech-industry-managed program that provides supply chain oversight via standardized audit criteria.

MedAccred accreditation is not the same as ISO certification, John Hastings of Johnson & Johnson told PlasticsToday at MD&M West in Anaheim, CA, last week. "ISO is an inch deep and a mile wide, whereas a MedAccred audit is an inch wide and a mile deep for the critical process," he explained. "Our audit criteria are developed for specific processes collaboratively with OEMs and relevant CMs."

The idea for MedAccred originated with Johnson & Johnson's DePuy Synthes group in Ireland, where a director of supplier quality, familiar with Nadcap, wondered why a similar accreditation program was not available for the medtech industry. That was in 2010, and an industry roundtable in 2012 officially kicked off the program. The MedAccred Plastics Task Group was formed about one year ago, added Hastings.

Editor in chief of PlasticsToday since 2015, Norbert Sparrow has more than 30 years of editorial experience in business-to-business media. He studied journalism at the Centre Universitaire d'Etudes du Journalisme in Strasbourg, France, where he earned a master's degree.

MedAccred has established rigorous audit criteria that incorporate industry standards along with specific OEM and contract manufacturer (CM) requirements. The program replaces some of the routine critical process supplier audits conducted by many OEMs and CMs with a single, robust audit. It is administered by Performance Review Institute (PRI), a not-for-profit organization that also supports the Nadcap accreditation program for the aerospace industry. MedAccred is modeled after this successful 25-year-old program.

When starting to design an inspection concept of this sort, the focus initially is on the requirements for the part being tested. The project team collaborates with manufacturers to develop the required quality-relevant test parameters, mostly related to surface defects and dimensional accuracy. They also identity the appropriate test methods. Kistler-developed sensors make it possible to integrate mechanical pressure and force and torque tests. Experts from the company’s competence center then design the test cell accordingly. In addition to determining the number and positioning of camera stations with lighting elements, the key factor at this stage is outlining the inspection path for the part.

Following inspection, the autonomous vehicle transports the tested parts to the warehouse and the test cell sends the analyzed data to higher-level QA or MES systems. Experts can then compare the quality data with the quality forecasts previously generated by ComoNeo PREDICT. If variances occur, the AI models are retrained using new test data.

The research project with the IWK Institute for Materials Technology and Plastics Processing is focused on injection molding of a medical part. The objective is to develop a system that provides medtech manufacturers with comprehensive automated random sample inspection, generating accurate AI-based quality predictions while injection molding is still in progress.

The process can be burdensome, as the samples are removed, transported, and tested manually, tying up resources. Moreover, the quality of the data depends on the skills and expertise of the personnel performing the inspections. Critical parts may have narrower tolerances and require more frequent spot checks, increasing the potential for human error. Automated, reproducible random sample testing can optimize the process.

Dr.-Ing. Oliver Schnerr is head of sales, Integrated Solutions Automation Solutions / Vision Systems / Fastening Technology at Kistler.

The objective is to achieve consistently smooth and efficient part handling throughout the entire test process. Integrated safety concepts monitor the systematic progression of the individual steps in the process — as well as the “handshakes” — to guarantee process reliability while preventing data loss. The automatic system then sends the collected data via an OPC UA interface to the operator's higher-level quality assurance system and to relevant databases for analysis.

The companies actively participating in the MedAccred Plastics Task Group, which developed the audit criteria for injection molding, reads like a who's who of medical manufacturing: Abbott, Baxter Healthcare, Becton, Dickinson & Co., Boston Scientific, Johnson & Johnson, Medtronic, Philips and Stryker on the OEM side; in addition to BMP Medical and MTD Micro Molding, GW Plastics, Mack Molding and Plastikos were among the suppliers taking part. The plastics injection molding audit criteria draw from established industry standards as well as manufacturing best practices.

The research project is also investigating possible ways to automate data matching and the adaptation of neural networks. Manufacturers not only gain the benefit of improved data quality from optical inspections, they can also design their entire process to be as rigorous and error-free as possible, even in complex production environments where a variety of different parts need to be tested.

Manufacturers typically rely on statistical process control (SPC) to verify quality. The frequency and scope of sample testing is defined, enabling users to monitor the production process according to predefined quality parameters.

The molded parts are serialized using individual QR codes and sorted onto trays. While production is still in progress, Kistler’s ComoNeo system monitors cavity pressures via pressure sensors. With support from appropriately trained AI, ComoNeoPREDICT software generates quality predictions for the individual parts. Driverless transport vehicles convey parts selected for spot checks to the optical test cell. This is the first time autonomous transportation has been used in this context. The parts then pass through the predefined inspection program and are checked for dimensional stability and surface defects as well as injection molding anomalies, such as black specks or moisture splay. Issues specific to plastics processing such as shrinkage due to cooling and crystallization are also taken into account.

A research project is exploring new avenues for AI-assisted automated optical quality assurance during the injection molding process.

Autonomous vehicles transport parts to the test cell and storage area. Image courtesy of OST – Ostschweizer Fachhochschule.

Quality control is an essential aspect of the production process, especially when it involves parts used in automotive and medical technology applications. The entire quality control process must be designed to ensure maximum precision and reproducibility, and typically requires reams of documentation. All of this is labor-intensive and time-consuming, and is reliant on expert personnel. Automation coupled with artificial intelligence (AI) may offer an alternative.

Thus far, MedAccred has established audit systems in the following areas: Cable and wire harness; heat treating; plastics; printed circuit board assemblies; sterilization; and welding. Injection molding is the initial subcategory within the plastics sector. MTD Micro Molding (Charlton, MA) is the first micro injection mold company to pilot the audit criteria, and the aforementioned BMP Medical is the first injection molding firm to complete a pilot audit against the criteria.

Switzerland-based Kistler, a developer of measurement systems and sensors, is collaborating with the Eastern Switzerland University of Applied Sciences (OST) in researching advanced quality-control technologies. In particular, Kistler is involved in a project with the university’s IWK Institute for Materials Technology and Plastics that fully automates the inspection of injection molded parts while harnessing the power of AI to hone quality predictions while injection molding.

Additional injection molding machines producing different parts can be integrated into this setup and incorporated into the material flow with the use of autonomous vehicles. In other words, the concept allows for automation of quality control in complex production environments as long as the test cell is equipped with the appropriate inspection programs: The inspection system recognizes the different parts and triggers the relevant test program.