Spunbond vs Meltblown Nonwoven: Differences, Specs, Uses

Core difference in one sentence

Spunbond and meltblown are both polymer-based nonwoven processes, but they are engineered for different outcomes: spunbond is optimized for strength and structure, while meltblown is optimized for fine-fiber barrier and filtration.

A practical rule of thumb: if the product must survive handling, stitching, abrasion, or repeated flexing, spunbond is usually the “skeleton.” If the product must stop fine particles or droplets efficiently, meltblown is usually the “filter core.”

How spunbond nonwoven is made (and what that implies)

Spunbond forms a web from continuous filaments. Polymer (most commonly polypropylene) is melted, extruded through spinnerets, drawn to orient and strengthen the filaments, laid down on a moving belt, then bonded (typically thermal calender bonding).

Typical spunbond process steps

1. Melt extrusion through spinneret (filament formation)
2. Air drawing/attenuation (molecular orientation increases strength)
3. Web laydown on a conveyor (randomized filament deposition)
4. Bonding (point-bond, area-bond, or through-air bonding depending on target feel/strength)
5. Finishing (hydrophilic/hydrophobic, antistatic, UV, flame retardant, printing, lamination)

What you typically get from spunbond

• High tensile and tear strength per gram because the filaments are continuous and well-oriented.
• Good converting performance (cutting, folding, stitching, ultrasonic welding) without excessive linting.
• Breathability and drape depend heavily on basis weight, bonding pattern, and finishing.

How meltblown nonwoven is made (and why it filters so well)

Meltblown uses high-velocity hot air to attenuate molten polymer into microfibers that are an order of magnitude finer than spunbond filaments. Those finer fibers create far more surface area and smaller pore pathways, which is why meltblown is the workhorse for filtration and barrier layers.

Typical meltblown process steps

1. Melt extrusion through a die with many small orifices
2. Hot air streams draw fibers to micro-scale diameters
3. Fibers are collected as a self-bonded web (often with minimal additional bonding)
4. Optional electret charging (electrostatic treatment) to boost capture of fine particles at low pressure drop

What you typically get from meltblown

• Excellent filtration potential due to ~1–5 μm fibers and high surface area.
• Low mechanical strength on its own; it is commonly laminated between spunbond layers (SMS/SMMS).
• Performance is highly sensitive to fiber uniformity, electret stability, basis weight, and storage conditions.

Performance differences that matter in real products

Strength and durability

Spunbond generally wins on strength because continuous filaments transfer load better than short, self-bonded microfibers. In supplier spec sheets, it is common to see spunbond tensile strength rise quickly with basis weight; for example, values around ~40–60 N/5 cm (MD) can appear in the ~20–25 gsm range, while meltblown at similar gsm is typically far lower and more prone to tearing during converting.

If a component must be pulled tight (ear-loop mask structure, gown seams, wrap, packaging), spunbond is usually the safer base layer. If the component must only sit protected inside a laminate, meltblown is appropriate.

Filtration and barrier

Meltblown’s fine fibers improve capture by multiple mechanisms (interception, inertial impaction, diffusion/Brownian motion). When electret-charged, meltblown can improve fine-particle capture without needing extremely dense webs, which helps keep breathing resistance manageable in masks.

In practical market offerings, 25 gsm meltblown filter media is frequently marketed with bacterial/particle filtration claims (often ~95–99% depending on test method and treatment). The real differentiator is not just “MB vs SB,” but whether the meltblown is engineered (and verified) for the target standard.

Breathability and pressure drop

Spunbond often has larger pores and higher air permeability at a given gsm, which can make it feel more breathable. Meltblown can be engineered for lower resistance, but if you push meltblown too dense to chase efficiency without electret treatment, pressure drop can rise rapidly.

A common procurement pitfall is specifying only filtration efficiency and gsm, without specifying allowable resistance (pressure drop). For respiratory and HVAC applications, you generally need both targets to avoid “filters that work on paper but fail in comfort or energy cost.”

When to use spunbond, meltblown, or a composite like SMS/SMMS

Many high-performing products combine both technologies so each layer does what it is best at. The most common composite is SMS (Spunbond–Meltblown–Spunbond), with meltblown as the barrier core and spunbond as protective outer layers.

Use spunbond when the priority is structure

• Reusable or semi-durable items (shopping bags, protective covers, agricultural sheets)
• Substrates that must be converted aggressively (seams, welding, lamination, slitting)
• Hygiene components where strength and cost-per-area dominate (backsheets, acquisition layers when finished appropriately)

Use meltblown when the priority is filtration or barrier

• Mask and respirator filter layers (often electret treated)
• Air and liquid filtration media (HVAC, vacuum bags, prefilters, industrial filtration)
• Oil sorbent pads and booms (microfiber structure captures oils effectively)

Use SMS/SMMS when you need both

If you need barrier performance but cannot tolerate tearing, linting, or handling damage, specify a laminate. In medical disposables, a common architecture is spunbond on the outside for abrasion resistance plus meltblown in the middle for barrier, sometimes with multiple meltblown layers (SMMS) to increase protection without over-thick outer layers.

Production and cost drivers (why prices and availability differ)

Even with the same polymer family (often PP), spunbond and meltblown have different economics because the equipment, throughput, and process sensitivity differ.

Throughput and scalability

Modern industrial lines can produce far more spunbond area per hour than meltblown. As a representative example from commercial line specifications, specific throughput figures in the range of ~270 kg/h per meter of die width for spunbond versus ~70 kg/h per meter for meltblown are commonly cited for high-output “spunmelt” platforms. This throughput gap is one reason meltblown can be more supply-sensitive, especially when filtration demand spikes.

Material selection and processing window

Meltblown typically needs polymers with rheology suited to stable microfiber formation and consistent attenuation; small changes in melt flow rate, air temperature, die condition, or contamination can shift fiber diameter and pore structure. Spunbond is generally more forgiving and produces robust webs across a wider range of settings.

Finishing requirements

If the end-use requires high filtration efficiency at low pressure drop, meltblown often needs electret treatment and careful packaging/storage. Those steps (and the testing required to validate them) can add cost beyond “gsm and width.”

How to specify the right nonwoven: a buyer’s checklist

To avoid receiving material that looks correct but performs poorly, specify performance metrics, not just “spunbond” or “meltblown.” The most effective purchase specs tie structure, filtration, and converting needs together.

Key specifications for spunbond nonwoven

• Basis weight (gsm) tolerance and thickness range (important for lamination and sewing/welding)
• Tensile strength and elongation in MD/CD (report units clearly, e.g., N/5 cm)
• Bonding pattern (point-bond/area-bond) and surface finish (hydrophilic vs hydrophobic)
• Color/opacity targets if used as an outer layer (uniformity matters in consumer-facing products)

Key specifications for meltblown nonwoven

• Filtration efficiency at the relevant challenge (particle size, aerosol type, flow rate) and the exact test method
• Pressure drop (resistance) at the same test conditions used for efficiency
• Electret treatment requirement and shelf-life expectations (charge stability can decline with heat, solvents, and moisture)
• Fiber diameter distribution or at least a proxy metric (pore size distribution / air permeability) for consistency control

If you are buying SMS/SMMS composites

Specify each layer’s gsm (or the total with layer targets), the bonding/lamination method, and the finished laminate performance (barrier + strength). A common pattern for medical masks, for example, is a spunbond outer layer + a meltblown filter core + a spunbond inner layer for skin comfort, but the correct gsm distribution depends on the required standard.

Common misconceptions (and quick ways to avoid bad calls)

“Higher gsm always filters better”

Not reliably. Higher gsm can reduce pore size, but it can also increase resistance sharply. A well-made, electret-treated meltblown can often outperform a thicker, uncharged web at a lower pressure drop. The correct approach is to specify efficiency and pressure drop together.

“Spunbond can replace meltblown for filtration if we just add layers”

Layering spunbond can improve coarse filtration, but spunbond fiber diameters and pore structures are typically not optimized for high-efficiency fine particle capture. If you need true filter-grade performance (especially near submicron ranges), meltblown (or other fine-fiber media) is usually required.

“Meltblown alone is fine for a durable product”

Meltblown is often fragile when handled, folded, or abraded. If the product must survive converting and real-world use, put meltblown inside a laminate and let spunbond carry the mechanical load.

A simple receiving inspection you can do without a lab

• Check basis weight with cut-and-weigh samples; require lot-to-lot consistency.
• Do a gentle tear/peel test: spunbond should resist tearing more than meltblown at similar gsm.
• For filter media, verify the supplier provides test reports for efficiency and resistance under the stated method; do not accept “BFE/PFE” claims without conditions.

Bottom line: spunbond and meltblown nonwoven are complementary technologies. Treat spunbond as the structural layer and meltblown as the functional barrier/filter layer, then specify measurable performance so the material you receive matches the intended application.