An engineer called because the pre-mixed and frozen (PMF) adhesive she purchased from another supplier didn’t come with analytical test data.
She wanted to know if suppliers were supposed to supply test data or was it something extra she had to request – e.g. a Certification of Analysis.
This is a great question. While I can’t speak to other suppliers’ processes, at Appli-Tec, we test all adhesives to meet our own internal specifications – as well as to customer-supplied specs.
When processing a pre-mixed and frozen (PMF) adhesive, Appli-Tec runs every material through several tests. Our objective is to ensure the material meets required specifications batch-to-batch. A few of these tests include Tg, Hardness, and Viscosity.
Tg measures the point at which a material shifts from a glassy state to a rubbery state.
Think of a nest of snakes. When it’s dark and cold, the snakes curl around each other to stay warm and exhibit little movement. When the sun comes out, the snakes warm up and begin moving, sliding past each other.
Because Tg correlates very closely with the resin/hardener mix ratio, we run each PMF processes material in-house using our own Differential Scanning Calorimeter (DSC). A precision instrument, the DSC allows us to measure Tg using a few milligrams of material – from a low of -120°C to a high of 275°C.
Over time, multiple tests for Tg allow us to build a history for each material. If a material has been mixed correctly, it will exhibit a Tg range. By running the test, we confirm the material’s Tg matches the range of previous batches – ensuring repeatability and ultimately, piece of mind for the customer.
This test is an easy way to check how hard or soft the cured PFM material is. Using a cured piece of the material, and a durometer meter, we measure the material’s hardness. Testing for hardness in combination with testing for Tg ensures the material has been mixed correctly and is curing properly – and thus will function as specified.
We test viscosity before a material is shipped. This test ensures that when mixing the material and packaging it, Appli-Tec uses as little pot life as possible. When the material arrives at your facility, you’re assured of maximum pot life – and work life as well.
To answer the question posed by the engineer about test data, we provide a Certificate of Conformance for all materials shipped at no extra cost to you.
In addition, we keep all test data on file and can supply it should you need it. We also provide full traceability back to the raw materials we purchase.
If requested, we can supply a Certificate of Analysis containing analytical data on particular lots of material for a nominal fee.
Currently, we can perform over 70 tests in-house on all materials we mix.
Appli-Tec PMF adhesives are much more than adhesives in a syringe. As an engineer working on critical, failure-is-not-an-option applications, you need to know and trust the material you’re using will work as specified – every single time.
Our goal is to guarantee consistent, repeatable results batch-to-batch. In other words, if you order 50 frozen syringes in October, and then another 50 in April, you’re assured each batch of material will perform exactly the same.
That’s the advantage of purchasing PMF adhesives from Appli-Tec.
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