When you think of particle analysis, odds are test sieves come to mind. Inspired by the sieve techniques used during the gold rush, test sieves allow lab technicians across dozens of industries to test and validate the quality of the material throughout a production line.
As the test sieve analysis process demands highly accurate and dependable test sieves, it is critical that you handle your sieves with care. This includes the way sieves are handled when applying maintenance techniques, such as applying heat for various reasons.
That said, how should heat be applied to test sieves, and what should you avoid?
W.S. Tyler has been a leading test sieve manufacturer for over 150 years and is here to share the knowledge within our four walls to help you obtain accurate and repeatable results for years to come.
With that, we wrote this article to take a deep dive into everything you need to know about applying heat to your test sieves. You will learn:
After conducting a test sieve analysis, you must clean your test sieves to prevent residual sample material from skewing future tests. To speed up the drying process, lab technics often place their sieves into an autoclave, which subjects the test sieves to elevated heat.
Another instance in which lab technicians heat their test sieves occurs after conducting a wet sieve analysis.
The finer material that washes away from the bigger particles must be dried to ensure they are dry and free-flowing. This will ensure you can successfully run these particles through a dry sieve analysis later.
Standard Test sieves are comprised of three main components. These components are the frame, the skirt, and the screening media.
Now, in order to successfully mount the screen media to the frame and keep it drum tight, a binding agent must be applied along the crease where the screening media and frame meet. This is generally either an epoxy or solder.
That said, when heating your test sieve, the binding that is used, whether epoxy or solder, is what is affected.
NOTE: When working with brass test sieves, applying heat may cause the different brass components to become discolored. This is only an aesthetic issue and will not affect the performance of the sieve.
To ensure your test sieves continue to produce accurate and repeatable results, you must pay attention to the temperature you apply. That said, the temperature threshold is different based on the binding used.
For epoxy sieves, temperatures should not exceed 200°F. For solder sieves, temperatures should not exceed 450°F.
You will want to ensure you are not overheating your test sieves. Depending on what binding agent is used on your test sieve, you can run into one of two after-effects of overheating, both of which permanently compromise the effectiveness of your sieves.
If you are working with an epoxied sieve, the main concern associated with overheating is the epoxy becoming brittle and cracking. If you are working with a soldered test sieve, overheating can cause the solder to soften and, in some cases, turn back into a liquid until cooled.
Regardless of the scenario, when the binding of your test becomes altered or damaged, the screening media will lose its proper tensioning. This, in turn, will cause your sieve(s) to skew your sieve analysis results.
Lab technicians typically apply heat to a test sieve for one of two reasons: to dry the sieve after cleaning or to dry out wet material to make it free-flowing. Regardless of why you heat your sieves, you must be sure to respect the heat threshold of the binding media.
Now that you understand the negative impact improperly heating your sieves can have on the accuracy of your sieves, you may be concerned if your sieves are producing accurate and reliable sieve analysis results. The best way to know for sure is to have your test sieves sent in for lab certification.
Over the past 150 years, W.S. Tyler has come to understand the struggles lab technics encounter and wants to help eliminate the test sieve hindrances preventing you from addressing other issues within your operations.
To learn more about the certification process and what steps you need to take to have your sieves lab certified, read the article below: