Introduction to SSMMS Nonwoven Fabric Application in Surgical Gowns (ARAS Nonwoven Treatment)

Surgical Gown Product Standards and Materials

Composite structure nonwoven fabrics (such as SMS/SMMS/SSMMS/SSMMMS) are the core materials for modern medical protective products, including surgical drapes, surgical gowns, and cleanroom garments. These multi-layer materials are typically composed of polypropylene fibers and combine the excellent strength of the Spunbond (S) layer with the outstanding filtration efficiency of the Meltblown (M) layer.

Among these, SSMMS represents a five-layer structure: a stack of three Spunbond layers (S) and two Meltblown layers (M) (S-S-M-M-S). This structure significantly enhances the material’s fine filtration, low pressure drop, good strength, and softness. The multi-layer Meltblown component gives SSMMS excellent high barrier properties against liquids and particulates, making it an ideal choice for manufacturing high-grade medical protective clothing. Furthermore, these materials are suitable for common sterilization methods, including steam, EtO (Ethylene Oxide), and low-temperature plasma.

In practical application, surgical gowns must cope with complex clinical environments, so the material must possess several key functions, including resistance to alcohol, blood, and oil, as well as anti-static properties and high barrier performance. To ensure the safety of patients and healthcare professionals, surgical gowns must meet strict international product standards, which mainly include:

1. US AAMI PB70:2012 Standard: This standard classifies protective apparel into four levels (Level 1-4) based on their liquid barrier performance. The protection level assessment is primarily based on the test results for the Critical Zone (i.e., the chest and sleeves) of the surgical gown.
   • AAMI Level 3 (Moderate Protection): Suitable for surgeries with moderate risk and moderate liquid exposure, this is the most widely used level in clinical practice. It requires passing the AATCC 42 (Impact Penetration Test) and AATCC 127 (Hydrostatic Pressure Test), with clear performance indicators required.
   • AAMI Level 4 (High Protection): Suitable for long, high-risk surgeries with large amounts of body fluid exposure. In addition to liquid barrier performance, this level must also pass the ASTM F1671 test to ensure resistance to penetration by bloodborne pathogens.
2. EU EN 13795:2019 Standard: This European standard specifies performance requirements for surgical gowns in areas such as microbial barrier property, liquid penetration, tensile strength, seam strength, and abrasion resistance. It classifies surgical gowns into two levels: Standard Performance and High Performance. This standard particularly emphasizes testing potential weak points, such as seams, to ensure the overall integrity of the protective barrier.

As a professional nonwoven machine manufacturer, AZX has compiled this table comparing surgical gown material parameters and processing methods that meet the standards, based on years of production data and experience from various collaborating manufacturers, for nonwoven fabric producers’ reference.

Compliance Standard	Main Material	Sewing Method
AAMI Level 3	Base fabric: ARAS 50gsm SSMMS Reinforcement: SF Material	Ultrasonic Sewing, Gluing on Reinforcement
AAMI Level 2	Base fabric: ARAS 35gsm SSMMS Reinforcement: SF Material	Ultrasonic Sewing, Gluing on Reinforcement
EN13795:2019 Standard Performance	ARAS 35/45gsm SSMMS	Ultrasonic Sewing
EN13795:2019 High Performance	Base fabric: ARAS 35/45gsm SSMMS Reinforcement: SF Material	Ultrasonic Sewing, Gluing on Reinforcement

Explanation:

1. ARAS stands for Alcohol Repellent, Antistatic.
2. Reinforcement refers to the reinforcing material for key contact areas of the surgical gown, such as the front chest and sleeves.
3. SF Material refers to a composite material made by compounding Spunbond + Film through a coating/lamination process.

SSMMS Production Process and Post-Treatment Technology – Key to Surgical Gowns

An SSMMS nonwoven fabric production line integrates three steps—spinning, web forming, and web consolidation—into one continuous production line. As a professional nonwoven equipment manufacturer, AZX not only provides efficient and high-quality SSMMS production lines but also offers professional nonwoven fabric post-treatment technology and solutions to meet the stringent requirements of medical-grade protective nonwoven fabrics.

1. SSMMS Production Process

The five-layer structure of SSMMS (Spunbond-Spunbond-Meltblown-Meltblown-Spunbond) is achieved through the perfect combination of the following three core processes:

• Spunbond (S Layer): Polypropylene (PP) is melted and extruded to form continuous filaments, which are then uniformly stretched and laid into a web by airflow. The S layer provides excellent tensile strength, abrasion resistance, and structural stability, serving as the skeleton of the surgical gown fabric. In the SSMMS structure, the three S layers are located on the exterior, providing reliable basic support and durability for the surgical gown.
• Meltblown (M Layer): The molten polymer is blown into ultra-fine fibers with extremely small diameters (typically in the micron range) by high-velocity hot air, and these fibers are then randomly deposited into a web. The M layer is the key to SSMMS’s barrier performance; its high-density, micro-fine fiber network structure can effectively filter bacteria, blood, and particulates, giving the material excellent hydrostatic resistance and filtration efficiency. SSMMS uses two M layers, which achieves a geometric increase in performance in microbial and liquid barrier properties compared to traditional SMS (one M layer), enabling it to easily meet the AAMI Level 3 protection challenge.
• Efficient and Stable Composite Structure: The S-S-M-M-S multi-layer composite structure has proven successful in practice. This structure fully utilizes the complementary effects of multiple spinning systems during the web forming process (detailed reference article: “Complementary Effect in the Web Forming Process and Multi-Spinning System Nonwoven Production Lines”), minimizing airflow fluctuation during the laying process and reducing phenomena like uneven web laying, fiber accumulation, or sparsity. Simultaneously, the AZX SSMMS Nonwoven Production Line can precisely control the fiber deposition and distribution of the five spinnerets (S-S-M-M-S), ensuring uniform thickness, tight fiber intertwining in each layer, thereby producing high-quality SSMMS nonwoven fabric with uniform structure, high softness, and a wide basis weight range (such as 8gsm to 80gsm).

2. Nonwoven Fabric Post-Treatment Technology

High-quality SSMMS nonwoven fabric is only the basic material for surgical gowns; nonwoven fabric post-treatment technology is the key to surgical gowns meeting high standards. (Post-treatment technology is also called finish technology or after finish technology, depending on what you want to call it.)

ARAS Treatment Technology is achieved through a professional post-treatment process, imparting anti-alcohol, anti-blood, anti-oil, and anti-static functions to the nonwoven fabric. It primarily uses an offline post-treatment method for processing. The main production process is as follows: Unwinding → Padding→ Feeding → Stenter → Multi-stage Drying → Cooling → Winding/Slitting

Among these, the Padding stage requires a dedicated liquid preparation system and post-treatment agents to give the nonwoven fabric its ARAS characteristics. The schematic diagram is as follows:

SF Material is produced through a coating/lamination compounding process, where Spunbond Nonwoven and PE Film are compounded in a double-layer or multi-layer manner. This creates a composite nonwoven material with high strength, high barrier properties, and high hydrostatic pressure, mainly used for the reinforcement part of surgical gowns. The main production process is as follows: Substrate Unwinding → PE Melting Extrusion → Coating/Lamination → Cooling → Winding/Slitting

The schematic diagram is as follows:

Ultimately, a surgical gown uses SSMMS nonwoven fabric treated with ARAS Treatment Technology as the base fabric, combined with the reinforcement of SF Material, allowing it to easily meet the requirements of AAMI Level 3 and other relevant product standards.

AZX, with its extensive customer service experience, provides you with complete and reliable production solutions for medical nonwoven materials, helping you succeed in the nonwoven industry.

If you would like to know more, please contact us, and we will share it with you without reservation.