What is soy fiber?
Soy fiber, also known as soy protein fiber,
is obtained from the soybean seed and by-products such as soy milk or tofu.
It is one of the few recoverable
plant-based protein fibers and is considered an ecological alternative to
silk due to its softness and natural sheen.
In textiles, this fiber combines the softness
of silk, the breathability of cotton, and the warmth of wool, offering
exceptional comfort even on the most delicate skin.
HIGH ABSORPTION CAPACITY
Distributes moisture throughout the entire garment, helping the body remain dry at all times.
ANTIBACTERIAL
Prevents the formation of bacteria, which—when decomposing in humid environments—are responsible for unpleasant body odour.
PROMOTES COLLAGEN PRODUCTION IN THE SKIN
This makes the garment ideal for atopic and sensitive skin.
HIGH PROTEIN CONTENT
Fabrics made from this fibre provide natural hydration to the skin, helping prevent itching and irritation.
BREATHABLE AND THERMOREGULATING
Allows full breathability, helping the body maintain an ideal temperature.
FUNGICIDAL
Prevents the formation of fungi.
NATURAL ANTIBIOTIC
Helps improve and prevent infections.
How is soy protein fibre obtained?
Soy protein fibre, a sustainable plant-based fibre ideal for underwear for sensitive or reactive skin, is produced by transforming protein-rich by-products from the food industry into a soft, breathable and eco-friendly textile. This process gives new value to discarded materials, aligning perfectly with the principles of circular economy and low-impact production.
Production process of soy protein fibre:
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Soy protein fibre is derived from plant proteins obtained from soybean by-products, following a circular and sustainable production model.
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The proteins are isolated and converted into a liquid solution suitable for fibre formation.
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Through an extrusion process, this solution is pushed through micro-nozzles to create fine, continuous filaments.
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The filaments are stretched to enhance strength, elasticity and uniformity, resulting in a soft, breathable and high-quality soybean fibre.
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The fibre is then spun into soybean fabric, known for its silky touch, moisture-management properties and exceptional comfort.
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Some of the remaining by-products can be reused as organic fertiliser, contributing to a low-waste, eco-friendly production cycle.
Why is it perfect for sensitive or atopic skin?
- Its extremely soft surface avoids friction and redness.
- It is hypoallergenic and antibacterial, reducing skin irritation and discomfort.
- It keeps the skin dry and fresh, preventing microorganism proliferation.
- Its composition rich in natural amino acids helps preserve skin balance and elasticity.
- These qualities make it the most recommended fabric for sensitive, reactive, or atopic skin.
Who is soy fiber recommended for?
Soy fiber is the ideal fabric for those seeking comfort, well‑being, and dermatological care without sacrificing sustainability:
- People with atopic or allergy‑prone skin.
- Those who suffer irritation or sensitivity to sweat.
- Users who prefer natural underwear without harsh chemicals.
- Those who value ecological, biodegradable, and locally produced fabrics.
At ZD Zero Defects, we transform this fiber into unique underwear garments, crafted in our factory in Barcelona, with rigorous quality control at every stage.
Featured products
Our soybean fiber products combine innovation, sustainability, and comfort. This extraordinarily soft, breathable, and antibacterial plant-based fiber cares for the skin and provides a light, natural feel throughout the day.
Soy fiber garments at ZD Zero Defects
At ZD Zero Defects, we work with soy protein fibre using an artisanal approach and a fully Made in Spain production model. Each garment is designed and manufactured in our factory in Mataró, where we use high-purity natural fibres and maintain strict control over every stage of the process.
Soy protein fibre allows us to create lightweight garments with a clean, premium finish. Cutting, spinning and sewing are carried out with precision to ensure a natural fit and long-lasting comfort.
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Anatomical pattern-making for a naturally adaptive fit.
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Flat seams and carefully finished edges for a smooth, comfortable result.
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Selection of high-quality plant-based fibres for a premium feel.
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Local production in our own factory, ensuring full traceability and consistent quality.
The result is underwear that you barely notice, yet always feel: true to the ZD essence since 1920.
Certifications and sustainable values
The soy fiber used by ZD Zero Defects comes from non‑genetically modified soy (Non-GMO) and undergoes environmentally respectful spinning and finishing processes.
We work with suppliers who guarantee biodegradability and compliance with Oeko‑Tex® Standard 100, ensuring the absence of harmful substances.
Additionally, our entire production is carried out entirely in Barcelona, ensuring a local, ethical, and transparent process.
How to care for your soy fiber garments
Soy fiber garments require delicate care to preserve their natural softness, antibacterial capacity, and hypoallergenic properties. Follow these guidelines to maintain them in perfect condition and extend their lifespan:
- Machine wash at max. 30 °C with delicate programs and mild detergents, preferably neutral.
- Do not dry clean. Chemical solvents can damage the natural protein structure.
- Do not use bleach or whiteners.
- Do not tumble dry — air dry in the shade.
- Do not iron.
ZD Tip: Turn garments inside out and use a laundry bag to maintain their silky texture longer.
ZD Zero Defects Commitment
Since 1920, we have manufactured our garments in Barcelona, combining craftsmanship, innovation, and sustainability.
Every fabric selected reflects our commitment to comfort, purity of raw materials, and durability.
Soy fiber perfectly embodies this philosophy: a natural, sustainable, and skin‑friendly fabric.
ZD Zero Defects — Tradition, innovation, and natural comfort.
