Fiber, padding, and odor-resistant fabric: Silk, the natural material that eliminates unpleasant odors

Human sweat is odorless in its original form. It is its decomposition, combined with the presence of greater or lesser amounts of sebum, that generates volatile, malodorous compounds characterized by more or less intense odors.

Sweat, in the form of an aqueous solution or water vapor, is produced in response to increases in internal temperature for the purpose of stabilization. Sweat is produced by a series of differentiated glands:

• Eccrine glands (salts, urea, and lactic acid)
• Apocrine glands (organic material, lipids, and proteins), most commonly found in the axillary and genital areas.

These types of secretions, combined with sebum, once deposited on the skin and tissues in direct contact, are an ideal substrate for bacterial proliferation and the resulting production of various odorous substances.

Once sweat and sebum are deposited on the skin and tissue, depending on the microclimate and environmental compatibility, the various organic elements are metabolized by different bacterial strains:

• Staphylococcus hominis,
• Corynebacterium spp.
• Micrococcus spp.

These bacteria are responsible for the formation of odors in bed linens made without odor-resistant fabric, and in technical and sportswear by triggering cellular processes that generate volatile organic compounds (VOCs), which are immediately detected by the olfactory receptors:

• Short-chain fatty acids (e.g., isovaleric acid)
• Sulfur compounds (e.g., thioalcohols)
• Amines (e.g., putrescine and cadaverine)

VOC concentrations and therefore the intensity of the odor depend on:

• The quantity and quality of deposits on skin and fabric (subjective),
• Personal cleanliness, which influences the number of bacterial microorganisms

The use of odor-resistant fabric or odor-reducing padding made with silk fibers hinders bacterial adhesion, reducing the production of malodorous compounds

Polyester and nylon are not ideal fibers for producing odor-resistant fabrics; they are highly hydrophobic and do not absorb moisture.

They bind and accumulate a lot of sebum, encouraging bacterial growth.

They are not breathable.

The odorous compounds bind stably and permanently to the aromatic groups of PET, making them almost impossible to remove even with intense washing and reactivating every time they come into contact with the skin.

Both polyester and nylon promote the growth of bacterial biofilms that are resistant to washing if not treated (chemically) with antibacterial finishes.

On the other hand, silk is naturally a self-cleaning, breathable, and thermoregulating fiber for odor-resisting fabric, ideal for sportswear, underwear, and bed linens.

Cotton absorbs considerable amounts of liquid but is unable to release it, creating wet or damp areas.

It absorbs lipids and, even after washing, ammonia- or organic acid-based odors.

It promotes bacterial growth if not properly dried or sanitized.

Silk quickly eliminates moisture and odors while maintaining freshness, creating odor-resistant fabric that maintain this characteristic even after numerous washes.

Wool and similar fibers such as cashmere or vicuna inhibit the proliferation of microorganisms thanks to their keratin protein, which has an acidic pH and a high sulfur content.

Its porosity and the numerous imperfections (scales)on the fiber’s surface favor the breeding grounds for fungi, bacteria, sebum, and moisture, making it a poor fiber for odor-resistant yarns and fabrics.

Silk, with its smooth, non-porous surface, offers no refuge to microbes, mold, and fungi. Odor-resistant fabrics and odor-resistant padding are naturally hypoallergenic.

Linen is hygroscopic: it absorbs large quantities of liquids and contaminants.

Its radium when drying prevents major odors.

In humid environments, it prevents the dispersion of VOCs, mold, and microbes.

Silk and the odor-resistant fabric made from it are water-repellent and repel grease, sebum, and mold even in critical conditions.