What Is Bamboo Fabric?

How is bamboo fabric made?

Bamboo fabric is made in one of two ways: by separating the plant’s natural fibres mechanically, much as linen is made from flax, or, far more often, by dissolving bamboo pulp and spinning the cellulose into a new, regenerated fibre.

Mechanical route: bamboo linen

The natural fibre is extracted with the methods used for flax or hemp, then spun into yarn. The Council of Fashion Designers of America (CFDA) describes this as labour-intensive and says it makes up very little of the bamboo fabric market.

A key step is retting, which frees the fibre from the stem. CFDA says chemical retting is frequently used because it is fast and gives uniform fibre, while dew retting, which needs no added energy, water or chemicals, is preferred.

Regenerated route: bamboo viscose, modal and lyocell

Most bamboo fabric is made with the same viscose process used for conventional rayon, according to CFDA. In that process, set out in a 2018 review in BioResources:

1. Cellulose is steeped in sodium hydroxide.
2. Carbon disulfide reacts with it to form cellulose xanthate, which is dissolved into a thick solution.
3. The solution is extruded into a coagulation bath containing sodium and zinc salts, where it sets as fibre.

Lyocell dissolves the cellulose directly in an organic solvent, NMMO, instead. The same review reports that more than 99% of the NMMO solution can be recovered. Modal comes from a modified viscose process that gives a stronger fibre when wet.

The US Federal Trade Commission (FTC) says no trace of the original plant remains in the finished rayon.

What are the properties of bamboo fabric?

The properties of bamboo fabric depend on the route: regenerated bamboo is soft, lustrous and drapes well, much like other viscose, while mechanically processed bamboo is absorbent and strong but coarser in the hand. CFDA gives the following profile.

Wet strength. Regular viscose is much weaker wet than dry. The 2018 BioResources review gives viscose a tenacity of 22–26 dry and 10–15 wet, in the same units: roughly half its strength is lost when wet. It gives lyocell 40–42 dry and 34–38 wet, so it keeps most of its strength.

Antibacterial claims. The FTC’s position is that dissolving the plant in harsh chemicals eliminates any natural properties, including the antimicrobial properties sellers have claimed for bamboo rayon. CFDA lists natural bamboo bast fibre as naturally antibacterial; that description concerns the mechanical fibre, not viscose.

How is bamboo fabric graded or measured?

Bamboo fabric has no grading scale of its own; what decides its quality is which fibre the bamboo became, how that fibre was made, and what the finished cloth has been tested for. Three things can be checked:

• The fibre route. Mechanical bamboo, viscose, modal and lyocell are different fibres. The EU defines each regenerated one by its process, so the fibre name already tells you how it was made.
• Strength figures. Regenerated fibres are compared in the lab by tenacity (breaking strength), dry and wet, as in the figures above.
• Certification. CFDA lists FSC certification for the forest source and chain of custody, and OEKO-TEX Standard 100 for testing finished products for harmful substances.

How does bamboo fabric appear on a clothing label?

On a regulated label, regenerated bamboo appears under its fibre name, such as rayon, viscose or lyocell, sometimes followed by “from bamboo”. In the US and Canada, “bamboo” on its own should mean fibre taken mechanically from the plant; in the EU, bamboo is not a permitted fibre name at all.

United States

• A product may be called bamboo only if it is made directly from bamboo fibre, which the FTC calls “mechanically processed bamboo”.
• Rayon made from bamboo must use a generic fibre name, such as rayon, or a term like “rayon made from bamboo”.
• Sellers need competent and reliable evidence, such as scientific tests, that a product really is bamboo fibre. Relying on a supplier’s say-so is not enough.

In August 2009 the FTC charged four companies with selling rayon as bamboo. In April 2022 it announced proposed settlements under which Kohl’s and Walmart would pay $2.5 million and $3 million, which it called by far the largest penalties in this area.

Canada

The Competition Bureau’s guidance says bamboo is not an acceptable generic fibre name unless the fibre has been mechanically processed. Acceptable names for the regenerated kind include “rayon”, “viscose”, “rayon from bamboo” and “viscose from bamboo”.

European Union

Regulation (EU) No 1007/2011 lists the permitted textile fibre names. Viscose, modal, lyocell and cupro each appear, defined by the process that makes them; bamboo does not appear as a fibre name.

Reading the percentages

The percentage on a label refers to the fibre, not the plant. A jersey T-shirt reading “95% viscose from bamboo, 5% elastane” is, for practical purposes, a viscose T-shirt with a little elastane for stretch.

How do you tell good bamboo fabric from poor bamboo fabric?

Good bamboo fabric is honestly labelled, made by a lower-impact process where it is regenerated, and sold without claims the fibre cannot support. These checks help:

1. Read the sewn-in label, not the swing tag. On a US or Canadian label, “bamboo” on its own should mean mechanically processed fibre. If a soft, slippery garment says only “100% bamboo”, treat the label as doubtful: the FTC says most, if not all, “bamboo” textiles are really rayon.
2. Look for the process in the fibre name. “Lyocell from bamboo” tells you the fibre was spun from a solvent of which more than 99% can be recovered, and lyocell keeps most of its strength when wet. CFDA recommends bamboo linen first and bamboo lyocell over bamboo viscose.
3. Check the hand against the claim. Bamboo linen has a somewhat coarse, linen-like hand; regenerated bamboo is soft and silky with good drape. A cloth sold as bamboo linen that feels like viscose deserves a question to the seller about how it was made.
4. Look for the certification marks CFDA names. FSC on the swing tag or product information speaks to the forest source; OEKO-TEX Standard 100 speaks to harmful substances in the finished product. Neither says the fabric is “bamboo” rather than viscose.

Myth: bamboo viscose keeps the plant’s natural antibacterial power. The FTC charged in 2009 that the rayon process eliminates such properties, and it requires scientific substantiation for any antimicrobial claim.

Red flags: “antibacterial” or “antimicrobial” on bamboo viscose; an unqualified “biodegradable”; and claims that the cloth is made “free of harmful chemicals”, a phrase the FTC challenged in its 2022 cases against Kohl’s and Walmart.

How do you care for bamboo fabric?

Follow the sewn-in care label, and handle bamboo viscose gently while it is wet, because regular viscose loses roughly half its strength in water.

• Washing: use the gentlest cycle the label allows, and avoid scrubbing or wringing the wet cloth.
• Lyocell from bamboo: lyocell can fibrillate, raising a fine surface fuzz, when it is rubbed while wet, so limit friction in the wash.

Is bamboo fabric sustainable?

Only partly: bamboo is a fast-growing grass that generally needs no pesticides or fertilisers, but most bamboo fabric is viscose, and the FTC says turning bamboo into rayon requires toxic chemicals and produces hazardous pollutants. Judged by the aims of sustainable fashion, the processing matters more than the plant.

• The plant: CFDA says bamboo relies mainly on rainfall, is harvested without tilling and helps reduce soil erosion. It lists clearing forests for plantations and depleting wild bamboo habitats as concerns, though it judges them not a major problem for the most part.
• Viscose: the 2018 BioResources review reports that only 70–75% of the toxic, volatile carbon disulfide used can be recovered during viscose production.
• Lyocell: the same review reports that more than 99% of the NMMO solvent can be recovered. CFDA describes lyocell as a closed-loop system using less toxic chemicals.
• Bamboo linen: mechanical processing avoids viscose chemistry, though chemical retting and wastewater can still pollute, according to CFDA.
• End of life: in 2009 the FTC charged that bamboo rayon products sold as biodegradable were not, because they would not break down in a reasonably short time.