Of course you need the right material, but once you have chosen that, which packaging makes the most sense? A major determining factor is how much handling do you want to do? So let’s review the epoxy application process.
Almost all epoxies used in fiber optics are two part and have dissimilar mix ratios. This, coupled with the relatively small amount of material being applied, means a static mixer is NOT a recommended way to go. There is too much risk of an incorrect mix ratio getting into the connector. So what are the options?
You could go with purchasing bulk material. However, this requires the most amount of handling. The resin and hardener will have to precisely weigh out before mixing. Any mistakes here will lead to problems down the road. Another often overlooked aspect in going this way is the additional exposure to the material. The work area must be very well ventilated to reduce the exposure. These chemicals are generally very safe to work with (please be sure to read any and all Safety Data Sheets before using or contact me with questions), but extended or increased exposure can accelerate allergic reactions like skin and eye irritation. By handling smaller amounts over less time, some allergic reactions can be avoided.
So this takes us to the most common packaging – premeasured two part packs. These take the precise handling out of your hands and decrease the time and amount of material you handle. This pack also increases your process control. These packs usually have a simple divider with a clip or a burst pack. You will simply break the pack and mix the two parts together. Some materials change to a mixed color to help identify when they are fully mixed. The next step is to get the material into a dispensing syringe. Once in the syringe it must be degassed. This is usually done in a centrifuge, but can also be done in a vacuum. Once they are degassed the material is ready for dispensing.
However, there is another packaging option to consider. To further reduce your handling and increase your process control, you can simply purchase the material in premixed and frozen syringes. In this case, the material will be measured, mixed, degassed and flash frozen. Here the material must be shipped on dry ice and stored in a -40 degree C freezer. This makes logistics a bit more complicated and expensive, but the payoff is no additional labor in preparing the material at your site. You will simply take the syringe out of the freezer, let it sit for less than five minutes and then use it.
The typical amount of material in the two part packs or the premixed and frozen syringes are 2.5 gram and 3 ccs respectively, but of course other packaging sizes are available. Just make sure you consider the working life of your material. Once the two parts of the material are mixed the working life is ticking.
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