MELTBLOWN NONWOVEN

Meltblown nonwoven fabric is a material made of ultra-fine polymer fibers produced by blowing molten polymer through tiny nozzles with high-speed air, forming a web of micro- and nano-fibers. The fibers are randomly deposited into a porous sheet with very small pore sizes.

This results in a soft, lightweight, and highly porous nonwoven fabric known for excellent filtration, absorbency, and barrier properties. In practical terms, meltblown fabric is the “fine fiber” layer often used in filters and masks, typically made from polymers like polypropylene.

Its high surface area and fine fiber structure make it especially good at trapping tiny particles, which is why it’s widely used for filtration (air and liquid), as well as in absorbent products and protective textiles.

Meltblown fabric is made by a specialized melt blowing process: a thermoplastic polymer (commonly polypropylene) is melted and extruded through a spinneret with many very fine holes. As the molten polymer exits these nozzles, high-velocity hot air blows the polymer streams, stretching them into extremely fine fibers before they solidify. These microfibers (often under 10 µm in diameter) are then collected on a moving screen or conveyor, forming a random fiber web. The fibers bond together (thermally or with air cooling) into a cohesive nonwoven fabric.
 

Materials:

• The primary polymer is polypropylene (PP) for most meltblown products, due to its favorable melting properties and filtration performance.
   
• However, other polymers like polyesters PBT or polyurethane (for elastic variants) can be used.
   

Often the meltblown web is treated post-production - for example, an electrostatic charge may be applied to enhance filtration efficiency (common for air filter media), or it might be calendered (pressed) to adjust thickness and pore size for specific uses. The result is a fabric produced in a single continuous process from raw polymer to fiber web, without any weaving or knitting.

Meltblown nonwovens are favored for filtration because their ultra-fine fibers create a dense matrix that can trap very small particles efficiently.

The fibers in meltblown filter media are much thinner than human hair or even most other synthetic fibers, giving the material a high surface area and very fine pore size. This structure enables high filtration efficiency - for instance, a meltblown layer can capture particles down to sub-micron sizes (∼0.3 µm) at efficiency levels of 95–99% (as seen in N95 or HEPA filters).

In addition, meltblown filters often take advantage of electrostatic charging (as an electret filter), which imparts an electric charge to the fibers and helps attract and trap particles without significantly impeding airflow. This means you can get high particle capture with a low pressure drop (i.e. air can still flow relatively easily).

Meltblown media also has a good dirt-holding capacity – its porous structure can hold a lot of particles before clogging, extending filter life.

In summary, the combination of microfiber structure and optional electrostatic enhancement allows meltblown filter media to achieve outstanding filtration performance (e.g. in masks, air purifiers, water filters) compared to coarser-fiber materials.

Elastic meltblown fabrics are specialty nonwovens made with elastomeric polymers (like TPU – thermoplastic polyurethane) that give the material stretch and recovery. Unlike standard meltblown (often polypropylene) which is not elastic, these variants can stretch significantly (several times their length) and return to shape. For example, a TPU-based meltblown can be stretched up to 500% (5×) in both machine and cross directions while maintaining excellent recovery. This elasticity, combined with the typical breathability of meltblown webs, opens up new uses.

In the textile and apparel industry, elastic meltblown fabrics are used as stretchable, breathable liners and composites. They can serve as inner linings in sportswear and footwear (e.g. in gloves or athletic shoes) to provide a lightweight, breathable stretch layer. The material’s porosity allows air and moisture to pass, which is great for comfort, while its stretch adds flexibility to the garment.

In medical applications, elastic meltblown is used for products like elastic bandage backings, wound dressings, or wearable medical device straps. Here it provides a gentle, conforming fit on the body, combined with the benefits of a nonwoven (like being lint-free and possibly breathable).

Another advantage: these TPU meltblown fabrics often have a lower melting point, allowing them to be heat-laminated directly onto other fabrics without additional adhesive. This makes it easy to bond a stretchable meltblown layer into multi-layer textile products (for instance, bonding an elastic meltblown membrane onto a fabric to make a stretchable composite for sports gear).

In summary, elastic meltblown nonwovens bring stretch to the traditional meltblown benefits of fine fibers and breathability, finding uses in high-performance apparel, medical dressings, hygiene products, and any application requiring a flexible yet breathable material.

Meltblown nonwovens are indispensable in medical products because of their excellent barrier and filtration characteristics coupled with softness and breathability.

A prime example is medical face masks and respirators: the meltblown layer in N95 respirators and surgical masks provides the high filtration efficiency needed to block viruses, bacteria, and fine aerosols – it can capture ~95% of 0.3 µm particles (hence “N95”) while allowing the wearer to breathe comfortably. This meltblown filter layer is what enables masks to achieve required Bacterial Filtration Efficiency (BFE) and particle filtration standards. For surgical gowns and drapes, meltblown fabric often serves as a breathable barrier layer that stops liquid penetration (like blood or fluids) and microbes, helping maintain a sterile field. Despite being a barrier, the material can still be lightweight and air-permeable enough to prevent excessive heat buildup for the wearer.

In wound care, meltblown nonwovens are used in some advanced wound dressings for their absorbency and soft feel. They can wick fluids and allow airflow, creating a conducive healing environment while protecting the wound.

Filter media in medical devices is another area – for example, meltblown filters are used in ventilators or breathing circuits to trap pathogens and dust. The key benefits across these applications are:

• High filtration efficiency (crucial for infection control in masks and hospital air filters).
   
• Fluid and bacterial barrier properties (to keep harmful substances out, as in gowns).
   
• Softness and skin-friendliness, which is important for direct-contact items like mask inner layers or dressings (meltblown can be quite soft and non-irritating).
   
• Sterilizability and disposability: Polypropylene meltblown can be easily manufactured to be single-use (reducing cross-contamination) and can handle common sterilization methods if needed.

Overall, meltblown nonwovens help medical products achieve the necessary protective performance (filtering microbes, blocking fluids) without sacrificing comfort, making them essential for personal protective equipment and other healthcare materials.

When evaluating or specifying a meltblown nonwoven, consider the following key technical specs and properties:

• Fiber Diameter: Meltblown fibers are extremely fine. Typical diameters range from about 1–10 µm (micrometers), with some advanced meltblown producing sub-micron fibers. Finer fibers generally mean higher filtration efficiency, but fiber size can be tailored per application. (By contrast, spunbond fibers are much thicker, ~15–35 µm.)
   
• Basis Weight (GSM): The fabric’s areal density, often given in grams per square meter. Meltblown fabrics for filtration or medical use are often in the range of 10–50 g/m² (lighter for disposable mask filters, heavier for industrial filters). Higher basis weight usually means a thicker fabric with potentially higher capacity to hold particles or liquids, but also higher pressure drop.
   
• Filtration Efficiency & Rating: If the meltblown is used as filter media, look at its efficiency for target particle sizes (e.g., “BFE 99%” for bacteria ~3 µm, or filtration of 0.3 µm particles for N95/HEPA). For example, N95 mask meltblown achieves ~95% filtration at 0.3 µm, while HEPA-grade meltblown can reach 99.97%. Also consider if it’s electrostatically charged (which boosts efficiency).
   
• Air Permeability / Pressure Drop: This indicates how easily air passes through. A good meltblown filter has low pressure drop for the given efficiency. Measured in units like mm H₂O or Pa at a certain flow, this is critical for breathability in masks or energy efficiency in HVAC. It’s often a trade-off with efficiency and basis weight (thicker or denser = higher pressure drop).
   
• Thickness and Pore Size: Related to basis weight, thickness can affect how the media is used (e.g., if it needs to be pleatable). Pore size (or mean flow pore) indicates the size of openings in the web; meltblown has very fine pore structure which correlates with filtration level.
   
• Tensile Strength and Durability: Meltblown on its own tends to have lower tensile strength (e.g., around 1–3 g/denier fiber strength, much weaker than spunbond). If the application requires mechanical strength (like a durable filter that won’t tear), you might need to reinforce the meltblown (e.g., laminate with spunbond layers as in SMS composites). Evaluate MD/CD (machine vs cross direction) strength, especially if the material will be converted on equipment.
   

Additional Properties: Depending on end-use, you may consider:

• Hydrophobic/Hydrophilic: Polypropylene meltblown is naturally hydrophobic (water-repellent), but treatments can make it hydrophilic if needed. Controlling this is important for liquid filters or absorbents.
   
• Oleophilic (Oil absorbency): Polypropylene meltblown is inherently oleophilic – it can absorb oil at many times its own weight, useful for spill pads.
   
• Chemical resistance: Varies with polymer. PP resists many chemicals; other polymers like polyesters or nylons might be chosen for specific chemical environments.
   
• Thermal resistance: If high temps are involved, polymer choice matters (e.g., PP melts ~160°C, whereas some high-performance polymers have higher melting points).
   
• Treatments/Additives: Some meltblown fabrics include additives or post-treatments for special functionality – antimicrobial treatment for healthcare, flame retardants for HVAC (to meet fire codes), anti-static for filter media in explosive environments, etc. These specs should be noted if relevant.

In short, match the meltblown’s specs to your application requirements. For a face mask filter, you’d prioritize high filtration efficiency and low breathing resistance; for an oil absorbent pad, you’d look at basis weight and absorbency capacity; for a composite in a garment, you might consider softness, weight, and whether it’s hydrophilic. Checking these technical parameters ensures the meltblown material will perform as needed in its intended use.

Standard meltblown fabrics (e.g., made from polypropylene) are not very environmentally friendly in their end-of-life – they are typically single-use and non-biodegradable, and if disposed improperly they can persist for a very long time. Polypropylene (PP), the most common meltblown polymer, can take hundreds of years to decompose (over 500 years) in the environment. That said, polypropylene is recyclable in principle: meltblown scrap or used material can be melted and reprocessed. However, in practice, recycling meltblown products like used filters or masks is challenging due to contamination (trapped particles, etc.) and because they are often integrated into composite products. So, most meltblown ends up as waste, unfortunately. 
 

On a positive note, there are eco-friendlier developments:

• Biodegradable Polymers: We can provide meltblown nonwovens are made from PLA (polylactic acid). PLA meltblown can biodegrade in 6–12 months under composting conditions, in stark contrast to PP’s persistence. Using PLA or even natural fibers like kapok in meltblown can greatly reduce environmental impact.
   
• Recycled Materials: GESSNER is also using recycled polymers to produce meltblown fabric. This doesn’t make the fabric biodegradable, but it does reduce the need for new raw plastic and helps repurpose waste. Recycled-content meltblown can maintain similar performance while cutting down plastic waste.

In summary, conventional meltblown fabric is not eco-friendly (not biodegradable and seldom recycled). To be sustainable, one should look for innovations like PLA-based meltblown or recycled-material meltblown which significantly reduce the environmental footprint. Also, proper disposal or recycling programs (where available) should be used to handle used meltblown products.