Reliable testing is the key to ultimate product safety

Every manufacturing process strives to achieve the ultimate product quality or negligible defects on a parts per million basis and, in pursuit of this aim, many manufacturers face huge challenges at every stage of often highly complex manufacturing processes to achieve 100% product quality and reliability. This is especially true when products rely on the safety of even small component parts that, if they fail, can affect not only the user’s safety but seriously impact on the reputation of the manufacturer.

The manufacture of aerosol stem and cup seals is a fine example of where a seemingly insignificant tiny rubber component can have a dramatic impact on both the functioning and safety of a pressurised container. The uncontrolled or sudden release of contents from some aerosols has to be a incident that is avoided at all costs. The likelihood of this eventuality can only be truly eliminated with the successful fusion of sophisticated manufacturing technology, highly effective quality monitoring and close working relationships with shared responsibility for the 100% safe functioning of the end product.

With globally dispersed production and filling of aerosol products, standardisation of production methods and materials for aerosol seals, and the effective monitoring of quality standards, becomes much more challenging. Not least, relationships between manufacturer and customer must be strong and work successfully across international boundaries.

So what should aerosol suppliers be looking for in the ideal relationship with a seal manufacturer?

Raw material analysis

No amount of sophisticated manufacturing technology or quality monitoring can compensate for raw material that is incapable or measuring-up to its performance requirements. Rigorous testing of raw material batches for hardness and performance, particularly those in contact with solvents, is critically important. Testing of every batch of raw material rubber and finished product with FTIR testing equipment provides a benchmark and traceability for all manufactured product. Further analysis in both qualitative and quantitative terms can also be undertaken with both a Thermogravimetric Balance Analyser and with the aid of high magnification digital microscopy.

Rigorous production quality monitoring

As aerosol seals are manufactured globally in many billions every year, few manufacturers of aerosol seals have the ability to highly accurately monitor the manufactured quality of this vast output. However, in some cases, sophisticated vision systems can now be employed to visually examine large batches of production output at high speed to ensure circumferential and thickness dimension consistency to high tolerances. Also high speed optical technology can be used to monitor for tiny surface imperfections ensuring batches comply to the highest performance criteria.

Integrated manufacturing

The traditional reliance on two manufacturing processes; rubber tube extrusion and milling (or cutting) tubes to manufacture individual aerosol seals, has always meant a greater opportunity for product consistency to be at the mercy of the reliability of both processes, rather than simply one. This is now changing with the emergence of new technology that fuses the tube extrusion process with the tube cutting process, bringing both processes into a more reliable, more productive and higher quality production environment. Removing many of the variables in the manufacturing process and being able to control quality in a single integrated manufacturing process means higher precision and more productive output.

Compliance systems and standards

Setting high production standards and undertaking rigorous and intensive measurement and monitoring at each stage of the manufacturing process has to be key to delivering products that consistently meet exacting performance criteria. Businesses that have developed control and compliance systems at every stage, provide higher levels of reassurance and safety. The deployment of Six Sigma methodology and optical measurement systems at critical stages of the manufacturing process ensures accurate data capture. With this, there is the ability to measure and report CPK values of consistently higher than 1.5, providing customers with the confidence of always receiving products within safe tolerances.

Mike Rimmer

Mike is Senior Chemist at Avon Engineered Rubber Ltd, the aerosol seal manufacturing division of Avon Group, based in South Wales, UK.

Talk to us to today to understand how Avon Group is ‘setting the standard’ in global aerosol seal development and production.