Microfibres

Concerning filament yarns, two were the most recent and striking developments: their application in textiles for automotives and the microfibres, that is yarns composed by filaments with a count finer than 1 dtex, hence fine than silk, for use in clothing. Microfilament yarns are offered in following versions: flat, untwisted, twisted, false-twist textured, false-twist textured and hard twisted, crepe and air-textured. Microfibres have obtained with polyester amazing results in terms of filament fineness: 0,4 dtex. These yarns established themselves on the market of the silk-like products and in part replaced previous types which too had been designed to imitate silk. These are polyester yarns woven into fabrics which were treated batchwise or continuously with a decorticating finishing process also on Italian machinery, to impart a soft feel and a silky look to the fabric.

It is also worth to mention, that microfibres and in particular polyester microfibres, accomplish the task of satisfying "fashion + function" requirements. In fact from the aesthetic point of view the outstanding filament fineness translates into fabrics with absolutely innovative drape and handle, which are very often obtained through an emery grinding process carried out once again on Italian machines. As regards comfort, microfibres allow to manufacture fabrics with a density of up to 30,000 filaments/sq.cm., which are absolutely waterproof and yet breathable thanks to their permeability to body moisture.

Microfibres are offered also in staple form in 0.85 dtex by several producers both for short staple spinning on ring or open-end machines, and for long staple spinning. A special version for nonwovens is also available. Developments in the fibre sector continue unceasingly all over the world. Nylon and polyester producers bring out fibres with special cross-sections which differ from the basic sections, i.e. round, multilobal and triangular sections. A separate sector is that of the hollow fibres: recently a polyester hollow fibre with round cross-section has been produced for underwear of tracksuits. This is the finest polyester hollow fibre so far produced, which has outstanding heat insulation properties. The researchers of the U.S. laboratory where it was developed claim that undershirts made of this thermal fibre are 23% warmer than currently available products. Moreover these fibres can be dyed at lower temperature and can also include a percentage of elastomeric fibre (see below) to impart stretch properties, a result which was almost impossible to obtain before.