As anyone who’s ever been on a blind date knows, compatibility is vital.
Get the chemistry wrong and one of you is likely to be leaving early, possibly wearing their dinner.
It’s a lot like that in the world of high purity manufacturing. When items are brought into a production assembly we need to be sure they’re chemically compatible – in short they’re not going to be reactive. New bits of kit MUST fit in with everything already present WITHOUT triggering any problematic chemical reactions.
Potential plastic problems
Think about a big family Christmas dinner, with all the great aunts and uncles. What’s the most important part of the preparation for the big meal? Not the cooking, oh no! What’s most important is the seating plan! Planning so that the ‘right’ people sit next to each other, and the ‘reactive’ people are miles apart is vital to making sure it doesn’t turn into one massive argument! It’s like that when you introduce something into a process line. Whether we’re talking about an in-line filter or a standard gasket, we need to be sure that it’s not going to react with the chemicals it’s exposed to. Any material that will come into contact with pharmaceutical or bioprocess components must comply with countless industry specifications before it comes anywhere near its end destination. Common issues with plastic items include: discolouring, softening, cracking, swelling, dissolving, and media permeating into the equipment. It’s not difficult to imagine how each of these side effects could pollute the media, leading to (very) expensive consequences.
Stress doesn’t help!
So, the chemicals in an assembly’s media can create some worryingly negative effects when they react with a peripheral made of the ‘wrong’ material. It’s important to remember that this effect is often worsened by temperature and pressure within a process system. To stop a peripheral item corroding, the types of mechanical pressure and stress it will be exposed to, and for what duration, need to be taken into consideration.
Too hot handle?
Heat is another major cause of unwanted chemical reactions within a production assembly. The hotter the environment gets the more reactive media becomes, increasing the chances of (for example) it permeating through plastics and polluting the line. Many chemicals should only be used within a prescribed temperature range – make sure you know what that is before your process line is up and running. Chemical reactions, dilution, and ambient temperatures can all increase the temperature of media in a production line, making unwanted reactions more likely.
Real-world testing
At the end of the day, it’s vital that any peripheral, before it’s introduced to a production assembly, is thoroughly tested. This usually means assessing its chemical compatibility, using established charts and codes – basically doing your homework. We’d also recommend you go further than that, and try some real-world testing. Get hold of some spares of a bit of kit and, in a safe controlled environment, introduce the media to them to see what reactions occur. It’s much better to find out the media and device are incompatible in a test scenario than it is discovering that when £100,000s of product are at risk on the assembly.
Share our know-how
If you’re unsure of whether you’ve got the product, conditions, temperatures, pressures or anything else for your assembly, drop us a line ([email protected]) our team would be more than happy to share their know-how with you.
Murph
