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The need for revalidation: time and cost savings can be made in cleanrooms

Marie Schwab, NPI manager, OGM looks at how changes to the material used in the manufacture of plastic components triggers the need for revalidation within the cleanroom and where time and cost savings can be made.

Sometimes, your material supplier may decide to change the formulation of a polymer or discontinue it altogether. If this is the case, an alternative material will have to be urgently sought and the production process revalidated before starting full manufacture. Revalidation of a component for any reason is, in essence, a repeat of all or part of the original validation, it can be very expensive due to the number of processes involved in the IQ (Installation Qualification), OQ (Operational Qualification) and PQ (Performance Qualification) tests. The aim is to prove that the intended manufacturing process will repeatedly and consistently deliver products of the required quality.  

There are also times when a change in materials is inevitable, due to new legislation, design updates or availability of an improved material. Here, the validation and revalidation services of an experienced injection moulding partner will help you avoid having to repeat work that will incur additional and otherwise unnecessary time and cost.   

By using medical grade materials, however, you can largely avoid having to revalidate under extreme time pressure because any changes to medical grade plastics must be declared by suppliers in advance, the industry standard is two years. Medical device manufacturers who are specifying medical grade plastics for their components, can therefore enjoy relative security of material supply once the plastic injection moulding process has gone through its original validation process. 

Revalidation in practice

When the need for a change arises, the material supplier will normally offer alternative materials. Your injection moulder should be able to assess the different options available and make recommendations taking into account the cost of the new materials as well as their quality, performance during manufacture and finished product characteristics. 

At OGM, we prepare a validation master plan detailing all necessary steps that is bespoke to each customer’s requirements. As the validation work progresses, all relevant information and results are documented in a validation protocol. Materials are ordered and subjected to moulding trials. These identify and quantify any changes needed in process parameters and establish their maximum and minimum limits. Multiple measurements at each stage of the manufacturing process allow completion of a full dimensional report which assesses the part’s conformance to its design drawing. 

If the results so far are satisfactory, PQ runs follow. The PQ stage checks whether the equipment and established process parameters can be relied upon to deliver the correct product quality in a real-life production environment. Finally, the drawings, production system, work instructions and other documents are updated to reflect the new material. 

Cleanroom facilities

When seeking an injection moulding partner for plastic component manufacture, a fundamental consideration is the quality and capabilities of its cleanroom facilities and the ability to manage additional demand which may be required with limited notice.  

First, the cleanroom’s ISO classification must meet or exceed the customer’s requirements for the types of products manufactured. For OGM this means ISO Class 7, which demands that particles with a diameter greater or equal to 5 microns should not exceed 10,000 per cubic foot of air (2,930 per cubic metre). It also requires 60 changes of HEPA-filtered air per hour. 

Importantly, providing full cleanroom, validation and moulding services in-house brings customers significant economies in terms of time, cost and project complexity. Considerations when partnering with an injection moulding company for validating components include: 

What can go wrong?

With the wrong choice of moulding partner or inadequate cleanroom facility, a validation project may fail – leading to delays and added expense.  

A typical result of failed validation is a product which does not meet its drawing’s requirements. This is often due to an inexperienced moulding company overpromising on the achievable tolerances, due to limited understanding and unrealistic expectations of the different moulded materials. Sometimes a validation process may not be sufficiently rigorous. In other cases, the moulder’s measuring equipment may be inadequate for the levels of precision necessary.  

At the opposite extreme, companies may over-validate – wasting time and money on validating to a higher level than the application needs. A related issue is poor communication and cooperation between the moulder and customer, which can result in project slippage and suboptimal outcomes. 

How to recognise a suitable moulding partner

The suitability of a moulding company can be assessed by research and questioning. A meeting should be arranged to view its facilities – including cleanroom and metrology equipment – and to see examples of its validation work. Customers must satisfy themselves that the company has carried out a large number and wide variety of substantial validation projects. 

The company’s technical expertise, including knowledge of what tolerances are feasible for each material, is crucial too. It should also demonstrate flexibility in tailoring validation packages according to available budgets as well as product specifications. 

Good communication is fundamental to collaborative project success. OGM assigns a dedicated project manager to every project to oversee it from start to finish and provide a single, easily accessible contact point. Key milestones are agreed at the beginning, with regular updates and meetings to keep the project on track. 

Clean and consistent results

Based in Oxford, OGM’s Class 7 cleanroom has been purpose-designed for efficient validation and production. Served by a variety of moulding machines, in sizes from 50 to 160 tonnes, it can manufacture a wide range of plastic medical components. Each machine has its own dedicated measuring and ancillary equipment, for convenience, speed and minimum risk of cross-contamination. 

The cleanroom is tightly sealed off from the rest of the building and all equipment is subjected to a strict cleaning regime. Sterility checks, carried out every month using contact and settle plates, are supplemented by regular swab testing of surfaces. An independent cleanroom validation takes place every six months, which is more frequent than the industry standard of 12 months. 

Products or components emerging from the OGM cleanroom are subjected to all relevant and requested sterility testing. Thanks to effective validation, customers can also be confident in the consistency of component dimensions and other characteristics affecting the final product’s function.  

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