Textile Recycling Technologies, Colouring and Finishing Methods

3.0 TEXTILE FIBRE PRODUCTION AND RECYCLING 
Textile fibre recycling of polyester, nylon, cotton and wool are discussed in this section, with a 
general focus on fibre-to-fibre (f2f) recycling, and overview of technologies for fibre blend 
recycling. Examples of current mechanical and chemical recycling stakeholders are highlighted. 
Table 2 summarizes options for mechanical and chemical recycling developed to commercial scale 
or demonstrated, for fibres of interest.
Fibre 
Mechanical 
Recycling 
Minimum 
Input 
Composition, 
% 
Chemical Recycling 
Minimum 
Input 
Composition, 
% 
Polyester 
Closed-loop 
✔
 
100 (f2f)* 
Closed-
loop
✔
*, **
 
 
70-80 
11 
/100* 
No 
requirement** 
(i.e. various 
polycotton blend 
ratios)
Other 
applications 
(open-loop or 
downcycled)
 
✔
Varied * 
(mainly post-
industrial) 
Nylon 
Closed-loop 
̽̽̽̽̽̽̽̽̽ relatively low 
volume 
✔
 
100 (f2f)* 
Must be same 
type (6 or 6,6) 
Closed-
loop 
✔
*
 
(only for 
Nylon 6)
 
100* 
Other 
applications 
(open-loop or 
downcycled)
✔
Varied * 
(mainly post-
industrial) 
Cotton 
Closed-loop 
✔
 
100 (f2f)* 
Closed-
loop 
✔
*, **
 
(regenerated 
cellulosic, 
not 100% 
recycled 
cotton 
product) 
100 * 
No 
requirement** 
(i.e. various 
polycotton blend 
ratios) 
Other 
applications 
(open-loop or 
downcycled)
 
✔
 
Varied * 
(mainly post-
industrial) 
Wool 
Closed-loop 
✔
>80 (f2f)* 
Closed-
loop 
X
 
N/A 
Other 
applications 
(open-loop or 
downcycled)
✔
30-100* 
(application 
dependent)
 
Table 2: General Summary of Available Recycling Options for Polyester, Nylon, Cotton, and Wool. 
* commercial scale 
** developed/demonstrated 
 

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3.1 Polyester 
3.1.1 Summary 
Polyester accounts for most of synthetic fibres produced globally (64%, 2016), and is the most 
widely consumed fibre.
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 Polyethylene terephthalate or PET is the most common subclass. The 
raw material components of PET are generally derived from petrochemicals, with main 
applications for fibre and packaging production, and a small proportion for film applications 
(Figure 9).
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 Polyester is characterized by its strength, crease-resistance, and lower water uptake 
(dries quickly). The environmental impacts of polyester are significant, with recent studies of 
microplastic release in aquatic systems which have characterized and reported the presence of 
substantial amounts of polyester (majority) among synthetic microfibres and particles collected 
from wastewater treatment facilities.
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Polyester is produced by condensing monoethylene glycol (MEG) and purified terephthalic acid 
(PTA) or dimethyl terephthalate (DMT).
6
To form fibres, PET pellets are heated, forming fibres 
and melt-spun into filament yarns. Yarns may be texturized to resemble cotton or wool yarns.
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To 
form fabrics, yarns are knit or woven. Approximately 7% of total polyester fibre production is 
derived from recycled polyester materials.
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Figure 6: Virgin polyester production methods.
 Modified and reproduced from [30,31]. 

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