Do You Need to Consider Thickness When Choosing Non-Woven Fabrics? Is Thicker Necessarily Better?

In domestic central sterile supply departments (CSSDs), the most commonly used packaging materials at present are non-woven fabrics, aside from cotton fabrics. When hospitals select non-woven fabrics, they often pay close attention to thickness (i.e., grammage). But is thicker non-woven fabric necessarily better?

The answer is no.

An increase in the thickness of non-woven fabric means an increase in weight per unit area, and the corresponding strength will also increase. However, due to its inherent structural characteristics, a thicker fabric does not equate to better microbial barrier performance. For example, using a thickened non-woven fabric: the increased weight of its spunbond layer cannot effectively enhance its bacteria-blocking ability. Only when the pore size of the key filter layer (i.e., the meltblown layer) can effectively filter out microorganisms and dust intrusion will the fabric’s bacteria-blocking performance meet the requirements. Additionally, increased thickness will affect the air permeability of the packaging material, leading to a higher probability of wet packs (a phenomenon where packages remain damp after sterilization).

In clinical practice, non-woven fabric packages may become damaged after sterilization. The main cause of such damage is that the microplastic fibers of non-woven fabrics will shrink to a certain extent after high-temperature sterilization. In practical use, this manifests as the non-woven fabric becoming brittle after sterilization compared to before. Therefore, applying excessive force to the fabric during use or using improper handling methods (when picking up or placing packages) can cause destructive damage to the packaging material. Moreover, using medical instruments with burrs on the edges or sharp surfaces can also result in damage to the non-woven fabric.

To address this issue, it is recommended that in clinical packaging operations:

• Ensure the packaging is neither too tight nor too loose;

• Handle packages gently (with light picking and placing);

• Adopt the double-layer packaging method recommended by standards.

These measures will significantly reduce the probability of damage. If one only intends to solve the damage problem by increasing the thickness of the non-woven fabric, in addition to ensuring the bacteria-blocking performance meets requirements, it is also necessary to closely monitor the probability of wet packs.

Key Terminology Notes (for Clarity in Medical Context):

• Central Sterile Supply Department (CSSD)：The standard English term for "消毒供应中心" in medical settings, referring to the department responsible for cleaning, sterilizing, and supplying medical devices and materials.

• Grammage：The professional term for "克重" in textile engineering, defined as the mass of a fabric per unit area (usually expressed in g/m²), which directly relates to thickness.

• Spunbond layer / Meltblown layer：Core components of medical non-woven fabrics. The "纺粘层" (spunbond layer) provides structural strength, while the "熔喷层" (meltblown layer) acts as the key barrier for filtering microorganisms—this distinction is critical to explaining the "thickness vs. barrier performance" relationship.

• Wet packs：A common term in sterilization practice, referring to packages that fail to dry properly after sterilization. Wet packs are considered unsterile and cannot be used clinically, so their probability is a key quality indicator for packaging materials.