Calculating the Throughput of a Discontinuous Screen Changer

by Justin Marriott , Product Manager - Key Filters

May 26, 2020


There are many options when it comes to your melt filtration system. Investing in the right screen changer for your process can mean the difference between saving time and material, and wasting those resources. This will affect your profits over the life of your extrusion line.

If you’re running a discontinuous screen changer, it might be time to upgrade.

Many times, when a production line is installed, it makes sense to have a discontinuous screen changer such as a manual or a slide plate. These types of screen changers are the least expensive and can be ideal if you’re running low throughput or have a line that needs to shut down regularly for product changes or cleaning. However, as your facility ramps up production, you’ll soon find that these low-cost options come with increasing operational constraints in the extrusion process. Discontinuous screen changers require the extrusion process to shut down to change screen packs when the extrusion pressure reaches a critical level. If you’re experiencing an increase in the number of shutdowns each week to change screen packs, you’re probably at a point where it makes economic sense to upgrade to a continuous-style screen changer.

Is there an easy way to calculate the amount of time and material I might be losing?

As the saying goes, “show me, don’t tell me.” Parkinson Technologies’ Key Filters brand developed an easy to use a calculator that will show you just how much you may be losing. All you need to know is the extrusion flow rate, your material cost, annual production run time, screen changes per day, and the average time to perform the screen change.

Use the calculator on our keyfilters.com/KCH page.

If you’re losing a significant amount of time and material changing screen packs, what can you do to reclaim both?

A continuous screen changer is a way to go. These types of screen changers will offer uninterrupted melt flow. However, of the three types, the continuous belt screen changer is the best option since it offers the most benefits. Please read a previous article “continuous screen changer 101” to learn more.

If you feel that it’s time to upgrade to a better melt filtration system for your extrusion line, please contact the Key Filters department and one of our engineers will be happy to discuss your application.