A buyer-focused guide to meltblown nonwoven fabric: where it sits in a mask stack, how fine fibres and electrostatic capture work, how to grade a roll across five levers, what to write into a purchase specification, and how to verify incoming batches before approval.
Where meltblown sits in a mask stack
In a disposable surgical or medical mask, the meltblown nonwoven fabric is the filter layer. It is sandwiched between spunbond layers that provide mechanical strength, shape retention and a smooth surface against the skin. The spunbond outer layer resists splashes and coarse dust; the meltblown layer does the fine-particle work; the inner spunbond layer keeps the structure comfortable and helps hold the pleats.
The layer order differs between a standard 3-ply mask and a 4-ply mask. A 4-ply construction adds a second meltblown layer rather than replacing the spunbond skins. That matters when a buyer compares quotations: the extra ply is filtration media, not extra outer fabric.
| Construction | Typical layer order (outside to inside) | What the extra layer changes |
|---|---|---|
| 3-ply | Spunbond + Meltblown + Spunbond | One filtration layer; standard structure for many EN 14683 Type II and Type IIR masks. |
| 4-ply | Spunbond + Meltblown + Meltblown + Spunbond | Second meltblown layer adds filtration media without changing the outer skin. |
In Justsun's range, the Surgical Mask 4-Ply Blue follows the four-layer order above, while the Surgical Mask Type IIR White uses the three-layer order. Both are CE marked and tested to EN 14683:2019, with BFE at least 98% and differential pressure below 49 Pa/cm2. The practical difference for buyers is how the filter stack is built, not whether the mask carries a CE mark.
Why meltblown filters: fine fibre web plus electrostatic capture
Meltblown nonwoven is made by extruding molten polymer through fine dies and drawing the filaments with hot air before they land on a collector. The result is a dense web of very fine, randomly oriented fibres with a high surface area. Particles travelling through the web are intercepted by three mechanisms: direct interception when a particle follows a streamline into a fibre, inertial impaction when a heavier particle cannot follow the bending airflow, and diffusion when very small particles move randomly and touch a fibre.
Meltblown media used in masks also carry an electrostatic charge. The charged fibres attract particles that would otherwise pass through the physical gaps in the web. This is why a meltblown layer can capture fine particles without being so tight that the wearer cannot breathe through it. The charge is applied during or after production, and it can be affected by humidity, storage conditions and handling. A roll that leaves the factory with good filtration performance can lose part of that performance if it is stored badly before conversion.
BFE and PFE are different test challenges
Buyers often see BFE and PFE side by side on a specification sheet and treat the higher number as the better product. They measure different things. BFE (bacterial filtration efficiency) challenges the mask with a bacterial aerosol at a defined particle size, commonly around 3.0 microns. PFE (particle filtration efficiency) challenges it with a non-bacterial aerosol at a smaller particle size, often around 0.1 microns. A mask can have strong BFE and lower PFE, or the reverse, depending on the meltblown web, the charge and the test conditions.
For EN 14683:2019, BFE is the headline filtration requirement, and Type II and Type IIR masks must meet at least 98%. PFE is not the pass criterion in that standard, but it remains a useful secondary indicator of how the medium performs against finer challenges. The right question for a buyer is not which number is higher, but which test challenge matters for the product's intended use and whether the supplier reports both under consistent conditions.
This is also where the difference between a general nonwoven overview and a filter-media specification becomes clear. If you are still deciding which nonwoven family suits a given PPE programme, the site's comparison of medical protective nonwoven fabrics covers the wider material choice. This article stays inside the meltblown layer itself.
Grading a meltblown roll: five levers a buyer should fix
Meltblown nonwoven fabric is not a single product. Two rolls with the same nominal description can behave differently in conversion and in the finished mask. The five levers below are the ones that most directly affect filtration, breathability and runnability. They interact, so a specification that fixes one without the others can produce unexpected results.
- Grammage — the weight of the web per unit area. A heavier web generally gives a stronger particle barrier but lowers air permeability and raises pressure drop. A lighter web improves breathability but weakens the barrier. Fix a nominal grammage with a tolerance band, because roll-to-roll variation affects both filtration and converting tension.
- Fibre fineness — finer fibres create a denser web with more surface area for capture. Finer fibres also reduce air permeability and increase pressure drop at the same grammage. Specify the fineness range that matches the target pressure drop rather than asking for the finest available.
- Air permeability and pressure drop — these describe how easily air moves through the medium. Lower air permeability means more resistance, which shows up as higher differential pressure in the finished mask. EN 14683 caps differential pressure, so this lever connects directly to compliance.
- Electrostatic treatment — the charge that boosts fine-particle capture. Specify whether the roll is electret-treated and how the supplier controls and reports it, because charge stability affects filtration after storage and conversion.
- Roll width and winding — width must match the converting line with a stated tolerance, and winding tension and splice frequency affect downtime. Loose or uneven winding can distort the web and change the effective grammage at the edges.
The trade-off direction is consistent: heavier web and finer fibres lower air permeability and raise pressure drop; a lighter web improves breathability but weakens the barrier. There is no setting that improves every lever at once. Grading a roll means deciding which combination the finished product can tolerate.
What belongs in a purchase specification
A purchase specification for meltblown nonwoven should be written so that a converter, a quality team and a supplier all read the same requirements. The checklist below covers the points that most often cause disputes after delivery.
- Material identity and polymer type, stated by the supplier.
- Nominal grammage with an agreed tolerance and test method.
- Fibre fineness range or an equivalent air-permeability target.
- Air permeability or pressure-drop target, expressed in the unit used by the converting line.
- Electrostatic treatment status and how it is controlled.
- Roll width, core size and winding tension with tolerances.
- Splice policy: maximum number per roll and how splices are marked.
- Roll diameter and weight limits for the unwinding equipment.
- Batch filtration report: BFE and, where relevant, PFE, with test conditions and sample identification.
- Packaging, labelling and traceability requirements, including batch number on each roll.
- Storage and handling instructions from the supplier.
- Acceptance criteria and the process for handling a non-conforming batch.
For masks that will be sold as EN 14683 products, the specification should also state how the incoming meltblown batch relates to the finished-mask test report. A roll that meets its own filtration target may still need adjustment in the mask stack to keep differential pressure below the standard's limit. The site's 3-ply surgical mask sourcing guide covers the finished-mask side of that relationship.
Incoming verification a buyer can actually run
Not every buyer has a filtration laboratory, but several checks can be done at goods-in and they catch most roll-level problems before conversion.
- Roll weight against nominal grammage. Weigh a roll, subtract the core, and compare the result with the nominal grammage multiplied by the roll area. A consistent shortfall across several rolls points to a grammage issue rather than a one-off.
- Width and winding. Measure width at several points along the roll and check for edge damage, telescoping or loose winding. Record splice positions and count them against the agreed limit.
- Visual defects. Look for holes, thick spots, contamination, colour variation and creases. A defect that repeats at the same interval often traces to a converting or winding problem rather than the web itself.
- Batch filtration report. Check that the report identifies the batch on the roll label, states the test challenge and conditions, and covers the properties in your specification. A report for a different batch or a generic report does not verify the delivered material.
- Storage and humidity control. Keep rolls in their packaging in a dry, controlled area and follow the supplier's storage instructions. Electrostatic performance and web integrity can both be affected by moisture and by prolonged exposure before conversion.
When a batch fails one of these checks, the useful next step is to isolate the roll, record the batch number and the measurement, and raise it with the supplier before the material enters production. That keeps the discussion on the specification rather than on the finished mask.
Meltblown inside SMS: the same filter medium in gowns and masks
SMS nonwoven fabric is a three-layer structure: spunbond, meltblown, spunbond. The meltblown core is the same family of filter medium used in masks, but in SMS it serves a different primary purpose. In an isolation gown, the meltblown layer provides a barrier against fluids and particles while the spunbond layers give strength, drape and abrasion resistance. In a mask, the meltblown layer is optimised for breathable filtration rather than drape.
Justsun's SMS Isolation Gown Yellow Knit Cuff uses an SMS construction and is CE marked to EN ISO 13795. For buyers sourcing both masks and gowns, the practical point is that meltblown quality affects both product lines. A supplier who understands the filtration and barrier role of the meltblown layer can discuss both, even though the finished products and their standards are different.
The barrier requirements for fluid-resistant masks are separate from the filter-medium specification. If splash resistance is part of the brief, the site's guide to fluid-resistant surgical mask levels explains how those levels are tested and what they mean for procurement.
FAQ
Is meltblown nonwoven fabric the same as the filter layer in a surgical mask?
In a standard 3-ply or 4-ply mask, the meltblown layer is the filter medium. It sits between spunbond layers that provide strength and surface properties. The meltblown web is where fine-particle capture and electrostatic attraction take place.
Is a 4-ply mask worth it over 3-ply?
It depends on the requirement. A 4-ply mask adds a second meltblown layer, which gives the filter stack more media to work with. A 3-ply mask can still meet EN 14683 Type IIR, as the Surgical Mask Type IIR White does with BFE at least 98% and differential pressure below 49 Pa/cm2. Buyers should compare the finished-mask test report and the intended use rather than assuming more plies is always better for every application.
Does a higher BFE always mean better filtration?
No. BFE and PFE use different test challenges, so a higher BFE does not automatically mean better performance against finer particles. The relevant question is which challenge matches the product's intended use and whether the supplier reports both consistently.
Can electrostatic treatment be lost during storage?
Electrostatic performance can be affected by humidity, storage conditions and handling. Buyers should follow the supplier's storage instructions, keep rolls in their packaging in a controlled area, and include electrostatic treatment status in the purchase specification.
What should I check first when a meltblown roll arrives?
Start with roll weight against nominal grammage, width and winding, and visual defects, then match the batch filtration report to the roll label. These checks are quick, do not require a filtration laboratory, and catch most roll-level issues before conversion.
If you are specifying meltblown for a mask or gown programme and want to compare it against a finished product, Justsun manufactures CE-marked disposable medical supplies and nonwoven protective products. You can review the 4-ply surgical mask and the Type IIR surgical mask as reference points for the filter stack, or send your specification and target batch size to request a quotation.