Convert mesh size to microns — or microns to mesh — instantly. Filter the table by extrusion application and find the right filtration fineness for your process. For a complete guide to mesh size selection by application, see our Polymer Melt Filtration guide.
Used by process engineers across blown film, cast film, fiber spinning, recycling and compounding.
Enter a value, select the conversion direction, and choose your application to see the recommended filtration range highlighted in the table below.
Filter table by extrusion application:
| Mesh | Microns (μm) | Typical applications | Notes |
|---|
Values are nominal reference values. Always confirm the micron rating of your screen packs with your supplier.
Mesh size selection is not arbitrary. The right filtration fineness depends on your polymer, contamination level, product quality requirements, and screen changer type. Here is the engineering rationale behind the most common configurations.
Post-consumer streams carry hard contaminants (paper, wood, sand) that would blind fine screens in minutes. Coarse filtration at 40–80 mesh removes gross particles. A secondary stage at 150–200 mesh polishes the melt. For contaminated recycled melts, Cofit offers GorillaBelt and ScrapeAway, which keep the line running without screen-change stops.
The workhorse range for most film extrusion. At 200 mesh (74 μm), gel particles and carbonised specs that cause pinholes and fish-eyes are captured before they reach the die. The AP Series, continuous and self-cleaning, covers this range and filters down to 3 μm without stopping the line.
Fiber spinning demands sub-70 μm filtration to protect spinnerets from micro-contaminants that cause filament breaks. At 325–400 mesh, differential pressure rises fast and manual screen changes become frequent: a continuous and self-cleaning screen changer is strongly recommended. The AP Series filters down to 3 μm, covering the requirements of these applications.
Too coarse, and contaminants reach the die, causing quality rejects; too fine, and differential pressure rises rapidly, forcing frequent interventions even with clean virgin material. Matching mesh size to the contamination profile of the incoming polymer is the first engineering decision: the converter and table on this page provide the baseline reference.
For the engineering principles behind mesh size selection — including contaminant types, differential pressure, and how filtration fineness affects product quality — see the complete guide to polymer melt filtration.
Mesh size is the number of openings per linear inch in a wire screen. Microns (μm) measure the actual aperture size — the physical gap through which particles can pass. The two are inversely related: higher mesh = smaller aperture = finer filtration. Use the converter above to find the micron value for any mesh count.
Blown film extrusion typically uses screen packs in the 100–200 mesh range (74–149 μm). For standard LDPE and LLDPE blown film, a 120–150 mesh screen removes gels and carbonised particles without excessive differential pressure buildup. High-clarity films and barrier applications often require 200–250 mesh (61–74 μm). When running post-consumer recyclate content, the coarser end of the range (80–120 mesh) is preferred to avoid premature screen saturation. For blown film, Cofit’s AP Series continuous and self-cleaning double cartridge screen changer filters down to 3 μm without stopping the line, also with low recycled content.
Change frequency depends on polymer cleanliness, throughput and filtration fineness. With clean virgin polymer a screen pack can run for many hours; with highly contaminated recycled melts, fine screens can saturate within minutes. Every manual screen change stops or disturbs the line and adds start-up scrap. Screen changers that keep the line running remove these stops: to see what they cost on your line, Calculate Your Lost Production.
200 mesh equals approximately 74 microns (μm), the reference value most widely used in extrusion screen pack specifications. Use the converter above for any other mesh-to-micron value, or consult the full table on this page.
325 mesh equals approximately 44 microns (μm). This is a fine filtration level used in fiber spinning (monofilament, multifilament), BOPP, and extrusion coating applications where sub-50 μm contaminants would cause filament breaks, optical defects, or coating failures. At 325 mesh, differential pressure across the screen pack rises significantly faster than at 200 mesh. At this fineness a continuous and self-cleaning screen changer is strongly recommended, because manual screen changes become frequent and each one stops the line.
Yes — directly and significantly. A clean screen pack contributes a baseline pressure drop (ΔP) across the filter, typically 20–80 bar depending on polymer viscosity, throughput, and mesh fineness. As the screen captures particles, ΔP rises progressively. When a screen pack is near saturation, ΔP can spike to 150–200 bar or more, causing melt pressure instability upstream that destabilises the bubble in blown film or creates thickness variation in cast film. Continuous screen changers maintain constant filtration area and constant ΔP — the AP Series keeps melt pressure stable during the self-cleaning cycle. This is the primary process engineering reason to upgrade from manual to continuous filtration.
Learn more about filtration equipment: Breaker plate vs screen changer — what’s the difference →
Enter your line throughput, stop frequency and shift schedule to see the production you lose to screen changes, in under two minutes.
Mesh and micron tell you how fine your screen filters — but consistent filtration under pressure is what keeps an extrusion line stable. Cofit builds screen changers that hold that fineness and keep the line running. View all screen changers →
Continuous and self-cleaning screen changer (AP Series)
Double cartridge filtration down to 3 μm for clean and semi-clean applications.
Automatic melt filtration system (GorillaBelt)
For high-contamination recycling.
Automatic, continuous and self-cleaning laser melt filter (ScrapeAway)
For high contamination levels, with filtration from 100 to 1,000 µm.
