This article explores the protective qualities and strength of SMS fabric, a versatile material widely utilized across industrial, medical, and consumer applications. Given its prominent use in healthcare settings for items such as coveralls and surgical masks, understanding its durability and protective capabilities is essential. By examining the properties and performance of SMS fabric, readers will gain insight into whether it truly offers the best protection and strength for various demanding environments.
Characteristics and Structure: SMS vs. SMMS Fabric
| Feature | SMS Fabric (Tri-laminate) | SMMS Fabric (Four-layer) |
| Full Name | Spunbond – Meltblown – Spunbond | Spunbond – Meltblown – Meltblown – Spunbond |
| Layer Configuration | 3 Layers: 1 meltblown layer is sandwiched between 2 spunbond layers. | 4 Layers: 2 meltblown layers are sandwiched between 2 spunbond layers. |
| Key Characteristics | • Lightweight
• Transverse and long-lasting strength • Provides comfort, water resistance, and breathability. |
• Identical core characteristics to SMS.
• The meltblown polypropylene layer is doubled, offering enhanced properties. |
| Filtration Efficiency | Moderate filtration; provides a reliable basic barrier against fluids and dust. | Superior filtration; the doubled meltblown layers effectively block smaller particles, bacteria, and viruses. |
| Barrier Strength | Standard barrier performance for general medical use. | Enhanced barrier strength; provides high-level fluid resistance and pathogen protection. |
| Best For (Applications) | General protective clothing, basic isolation gowns, and standard face masks. | High-filtration surgical masks, N95 masks fitted with filters, and high-risk surgical environments. |
| Safety Compliance | Suitable for environments requiring moderate barrier protection. | Preferred for stringent safety regulations and high-stakes medical procedures. |
What are the functions of each fabric?
Spunbond Polypropylene
The process of creating spunbond fabrics involves extruding a melted polymer through a spinneret primarily to produce continuous, uniform filaments that can be efficiently assembled into nonwoven fabrics. This method is employed because it allows for the rapid production of long, thin filaments with consistent diameter and properties, which are essential for the strength, durability, and uniformity of the final fabric. The term “spunbond” specifically refers to these long, continuous filaments, which are advantageous over staple fibers due to their higher production speed and better bonding capabilities. By extruding the polymer in this manner, manufacturers can control the filament dimensions and orientation, resulting in fabrics with tailored characteristics such as breathability, filtration efficiency, and tensile strength. This process is particularly significant in applications like medical textiles, geotextiles, and hygiene products, where the quality and performance of the fabric are critically dependent on the filament formation process. Therefore, the extrusion through a spinneret is fundamental to achieving the desired filament properties, making it a key step in the production of spunbond fabrics.
This table lists the advantages and defects of spunbond.
| Advantage | Defect |
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Meltblown Polypropylene
The melt-blown process functions similarly to the spunbond process because both techniques involve extruding molten polypropylene through fine nozzles to produce fibers; however, the melt-blown method is specifically optimized to generate extremely low-diameter fibers, typically in the range of 2 to 3 micrometers. This fine fiber diameter is crucial for creating a dense, nonwoven web with a high surface area, which significantly enhances filtration efficiency. In the context of face masks, melt-blown layers serve as the primary filtration medium because their intricate fiber structure effectively traps airborne particles, including bacteria and viruses, while maintaining breathability. The electrostatic charge retained within these fibers further improves filtration performance by attracting and capturing particles that are smaller than the pore size of the web. Consequently, the melt-blown process is essential for producing the critical filtration layer in masks, providing both high filtration efficiency and comfort for the wearer.
This table lists the advantages and defects of meltblown.
| Advantage | Defect |
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Structural Characteristics: Layered Design for Enhanced Protection
The layered design of SMS fabric results in a material that balances breathability with barrier performance. The outer spunbond layers offer durability and resistance to physical stress, while the meltblown core provides high filtration efficiency. This structure ensures that the fabric can withstand demanding environments, making it suitable for use as disposable face masks, surgical masks, protective gowns, and other PPE.
Core Properties: Breathability, Durability, Barrier Performance, and Strength
- Breathability: Despite its barrier capabilities, SMS fabric maintains adequate airflow, ensuring comfort during extended wear.
- Durability: The spunbond layers confer mechanical strength, enabling the fabric to resist tears and punctures.
- Barrier Performance: The meltblown layer acts as an effective barrier against liquids, bacteria, and particulates, essential for medical personal protective equipment.
- Strength: The overall fabric exhibits high tensile strength, making it suitable for industrial PPE and medical protective devices.
Because this fabric has three layers, it is known as SMS, emphasizing its layered construction and protective capabilities.
SMS Fabric Used in Medical Field
Medical professionals use disposable SMS nonwovens extensively. Since these products are single-use, they will be incinerated after each use. The spread of contaminants is therefore reduced.
SMS Nonwovens are used for a range of purposes, including:
- Isolation gowns
- Surgical face mask
- Single-use cap
- Scrub suit
- Shoe cover
- Bed linen
- Surgical drape
- Lab coat
- Sterilization wrap
Use in Healthcare: Surgical Masks, Coveralls, Gowns, and Sterilization Wraps
In the healthcare industry, SMS fabric is a cornerstone material for medical masks such as surgical masks, disposable face masks, and N95 masks fitted with filters. Its barrier properties help prevent the transmission of infectious agents. Additionally, SMS fabric is used in surgical drapes, sterile gloves, and sterilization wraps, providing sterility assurance level (SAL) and ensuring compliance with standards like FDA clearance and USP 800. Its durability and barrier performance make it ideal for personal protective equipment (PPE) that must withstand rigorous sterilization and handling.
Industrial Applications: Protective Clothing, Filtration, and Packaging
Industries utilize SMS fabric for protective clothing such as coveralls, gowns, and safety masks. Its strength and barrier properties protect workers from chemical splashes, particulates, and biological hazards. The fabric’s filtration capabilities are also exploited in industrial filtration systems, while its lightweight nature makes it suitable for packaging and protective covers.
Consumer Uses: Disposable Apparel and Hygiene Products
In the consumer sector, SMS fabric is used in disposable apparel like hygiene products, face masks, and protective clothing for personal safety. Its cost-effectiveness and performance make it a preferred choice for single-use applications, ensuring hygiene and safety in everyday environments.
The manufacturing process of SMS Nonwoven Fabric
The Thermo-bonding Manufacturing Process
There are many ways to bond SMS fabric, but the most common method is thermo-bonding. One side of the roller has a smoother surface, and the other side has tiny pins. Together creates embossed finishes on the opposite side of the fabric. These pins penetrate the fabric only 20% and aid in bonding the layers.
Test Methods and Standard of SMS Nonwoven Fabric
Thermo-bonded thermal bonded SMS fabric samples were tested for functionality and comfort properties.
This table shows how SMS fabric is tested and the way meets the quality.
| Test Methods | Testing Standard |
| Tensile strength | ASTM D5034 |
| Thickness | ASTM D1777 |
| Tearing strength | ASTM D5587 |
| Abrasion resistance | ASTM D1175 |
| Hydrostatic Head | ISO 811 |
| Air permeability | ASTM D737 |
| Antistatic | EN 1149 |
What is the rating of protective materials and PPE?
Materials for the surgical gown, isolation gown, and surgical drapes are rated on the ability to block liquids and liquid-borne pathogens. There are 4 levels of protection per the AAMI: PB70 2012 standards.
For more detailed information, refer to the Medtecs guide to isolation gown and surgical gown selection.
Frequently Asked Questions
Q: Is SMMS more effective than SMS?
A: Some products may feature multiple layers of melt-blown material sandwiched between spunbond layers. Because melt-blown layers serve as the primary filtration component of the fabric, increasing the number of these layers enhances the overall filtration efficiency. Consequently, SMMS fabrics, which contain more melt-blown layers than SMS fabrics, typically offer a higher filtration rate.
Q: Why is SMS fabric the preferred choice for PPE in medical and industrial sectors?
A: SMS fabric is the industry standard because it offers the perfect balance of high performance, cost-efficiency, and ease of manufacturing. Its unique triple-layer structure provides a superior barrier against fluids and pathogens while maintaining breathability and high tensile strength, ensuring full compliance with rigorous safety and regulatory standards.
Conclusion:
A comprehensive understanding of the manufacturing processes and standards governing SMS and SMMS fabrics further enhances procurement decisions. For instance, knowing that SMS fabric is typically produced through a spunbond-meltblown-spunbond process highlights its layered structure, which contributes to its strength and barrier properties. Conversely, SMMS fabric, with its meltblown layer sandwiched between spunbond layers, offers superior filtration efficiency and breathability, making it particularly suitable for medical applications requiring high levels of protection. Additionally, familiarity with industry certifications and testing protocols ensures that selected fabrics meet regulatory requirements such as ASTM or EN standards. By integrating this technical knowledge with practical considerations like durability, comfort, and cost, procurement professionals can optimize PPE selection to meet the specific needs of their environments, thereby enhancing safety and operational efficiency.
References
- Engqvist, H. (2020, March 1). Nonwovens— The Fight For Better Healthcare. Nonwovens Industry Magazine.
- Technologies, B. T. (2021, August 23). An Introduction to SMS Material. Blue Thunder Technologies.
- Vishwakarma, S. V. (2021, January 15). Surgical Gowns Using SMMMS Method. Textile Study Center.
- Shende, P. (n.d.). Impact and Scope of Intelligent Textiles in Health Care | Abstract. Journal of Bioequivalence & Bioavailability. Retrieved September 3, 2021, from
- Spun bonding technology and fabric properties: A review. (2017, April 17). Journal of Textile Engineering & Fashion Technology.
- F.S.K. (2015, September 1). A Review of Isolation Gowns in Healthcare: Fabric and Gown Properties. PubMed Central (PMC).
- Vishwakarma, S. V. (2021b, January 15). Surgical Gowns Using SMMMS Method. Textile Study Center.
