With sizes around 20μm we find ourselves in a world where a strand of hair is as thick as an oil storage tank, dirt particles big as St Bernhard dogs and bacterias have the size of footballs. In this environment there are other fysical laws dominating than in our regular world. This magical world is ruled by molecular structures and capillarity forces.

Imagine the microfiber as a fine web that captures and keeps dirt particles as nothing. The more and thinner fiber, the better effect. A regular microfiber cloth contains about 1,6 million meters of microfiber that cleans on a bacterial level and absorbs grease more than 80 times as efficient as a cotton cloth.

What is a microfiber?
The weight of a fiber is measured in decitex (Dtex). Dtex is the weight of 10 000 meters of a fiber. The thinner the fiber, the lower the Dtex. In a industrial context, the microfiber is defined as a fiber with a Decitex lower than 1, which means that a 10 000 meters of a fiber weigh less than a gram.
Denier (D) is an alternative denomination that originates from the weight of 9 000 meters of a fiber. Hence the limit for microfiber measured in denier is 0,9.

I litterature, on packagings and in daily talk these denominations are constantly mixed up. In reality this doesn´t matter since Decitex (Dtex) och Denier (D) are not so far apart.

Different types but with the same effect
Microfibers can be made from different materials but polyester and polyamide is by far the most common. Due to technical reasons most of the really thin microfibers are made as conjugated SPLIT-fibers. The SPLIT-fibers consist of different materials to make the splitting process easier. It is only after the splitting process that the actual microfibers occur.

There are two general types of microfibers.
The most common one is the PA/PET fiber that is splitted in a light NaOH-solution or by mechanical force from water jets or similar.
The other one consists of CO-PET that is an easy solvable material where the microfibers from PET are included. In the splitting process the CO-PET is dissolved and the microfibers appear.

The cross section of a conjugated SPLIT fiber can look a bit different from different manufacturers. There are ORANGE-, SLICED-, SEA ISLAND och STAR-shaped cross sections. From a quality point of view there is no difference between these variations.

DIRECT SPUN is another type of microfiber. This fiber is directly made as a microfiber without any splitting process needed. This is a common type among the courser microfibers. DIRECT SPUN can also be made really fine but this is a very expensive process and therefore very rare.

Why is the quality different?
Microfibers have a well proven cleaning and absorbtion effect, specially when the microfiber has a Dtex less than 0,5. The effect is further increased all the way down to 0,3 Dtex. When the microfibers get thinner than this, it is hard to notice any improved efficiency.

When  a manufacturer give the specifications for the microfiber he always talks about the theoretical measure of the fiber. This measure is around 0,2-0,3 Dtex for most of the SPLIT fibers. This theoretical value requires a 100% efficient splitting process, that in reality never occurs.

Only DIRECT SPUN-fibers give a reliable theoretical value.

In reality the quality of the microfiber is due to the outcome of the splitting process. High quality has a higher splitting rate, which means that more of the conjugated fibers has separated from each other. The splitting rate is set by the quality of the yarn and the skill in the splitting process.
If you only check the theoretical values of the Dtex you can never tell good quality from bad!

Yarn or fiber
The microfibers are spun to a yarn. The yarns are also measured in Dtex or D. If a yarn has a Dtex of 150 it simply means 10 000 meters of the yarn weigh 150 gram. This yarn can then consist of for example 500 microfibers of 0,3 Dtex.

The corseness of the yarn has no impact on the function. It only effects the structure of the fabric.