Why Extrusion Downtime Costs More Than You Think

Every time an extrusion line stops for a screen change, the visible downtime is only part of the real cost. On top of it come startup scrap and the settling period, when off-spec product is made until melt pressure is stable again.

The calculator above uses your actual production parameters — throughput, stop frequency, stop duration, and shift schedule — to quantify how much production and revenue you lose each month.

What the Calculator Measures

The calculator quantifies the gap between your current production and what your line could produce with zero unplanned filtration stops. Here is what each input means for your results:

  • Throughput (kg/h): Your line’s rated output: the higher it is, the more production you lose at every stop.
  • Stop frequency: How often your operator changes screens. On virgin resin lines, this may be once every few days. On post-consumer recycling lines with heavily contaminated material, it can be every few minutes.
  • Stop duration: The total time from production stop to stable quality output. It is often much longer than the actual screen swap time, because it includes purging, pressure stabilization and quality checks.
  • Shifts and working days: More operating hours mean higher absolute losses from each stop event. A 24/7 recycling operation loses 3x more than a single-shift converter from the same stop frequency.

How Screen Changers That Keep the Line Running Eliminate These Losses

These screen changers clean or renew the filter media without stopping the extrusion line: no stops for screen changes, no restart scrap and more stable melt pressure.

Cofit offers three technologies that keep the line running, with more than 800 installations. Belt systems like the GorillaBelt advance a filter belt automatically from a supply roll, using two wedges as a seal — minimizing material waste. ScrapeAway, an automatic, continuous and self-cleaning laser melt filter, scrapes contaminants off laser-drilled filter discs while it filters, with melt loss below 1%. The AP Series, a continuous and self-cleaning double cartridge screen changer, maintains a constant flow with filtration fineness down to 3 microns.

Unlike manual systems, these solutions avoid the pressure swings caused by stopping the line for a screen change. This pressure stability directly translates to consistent product quality — fewer gels, fewer dimensional variations, and less scrap. Learn in detail how the AP Series continuous and self-cleaning screen changer works.

Related Tools

Filtration efficiency also depends on choosing the right mesh fineness for your application. Finer mesh catches more contaminants but reduces flow rate and increases how quickly differential pressure builds up.

Use Cofit’s free Mesh-to-Micron Conversion Tool to convert mesh and microns and see typical filtration levels by application.

Frequently Asked Questions

The calculator gives a conservative estimate based on the parameters you enter: it calculates lost production from throughput, stop frequency, stop duration and shifts and, if you enter the product value, converts it into lost value. Real losses can be higher, because the calculator does not account for startup scrap, energy used during the stop or quality losses while pressure stabilizes.

You need only a few inputs: line type, throughput (kg/h or lbs/h), how often the line stops for a screen change, how long each stop lasts, shifts per day and working days per week. The product value is optional. If you are unsure about stop duration, count from the moment production stops to the moment stable-quality output resumes, not just the screen swap time.

Payback depends on the model and on your line conditions. If you would like a quotation, we will calculate your ROI together using your plant’s actual data: request a technical alignment.

Yes. The calculator works for any extrusion process where screen changes cause production stops — including recycling, blown film, cast film, pipe, profile, sheet, compounding, and fiber extrusion. The inputs are universal: throughput, stop frequency, stop duration, and operating schedule. The results are most impactful for high-throughput lines and applications with frequent screen changes, such as post-consumer recycling.

Ready to Eliminate Filtration Downtime?

Our managers can recommend the right screen changer for your application, throughput and contamination level.

Request a Technical Alignment