Journal of Cleaner Production 112 (2016) 4445e4451

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Journal of Cleaner Production

journal homepage: www.elsevier.com/locate/jclepro

Preparation and physical properties of regenerated cellulose fibres

from cotton waste garments
L.V. Haule*, C.M. Carr 1, M. Rigout 1
School of Materials, University of Manchester, Manchester M13 9PL, UK

a r t i c l e i n f o a b s t r a c t

Article history: The aim of this research was to investigate the recycling of cotton waste garments by fibre regeneration.
Received 20 February 2015 Easy care finished cotton fabrics and indigo dyed waste denim garments were successfully purified,
Received in revised form dissolved in a suitable solvent and spun into fibres. The physical properties of the resultant fibres were
18 August 2015
compared with standard lyocell fibres spun from wood pulp and the fibres regenerated from the cotton
Accepted 19 August 2015
waste garments exhibited improved mechanical and molecular properties relative to the typical fibres
Available online 29 August 2015
regenerated from wood pulp. Furthermore the results have indicated that a suitable blend of wood pulp
and pulp reclaimed form cotton based waste garments can produce fibres with properties that are in-
Keywords:
Recycling
termediate to cotton and lyocell fibres. The results suggest an alternative approach to fibre resource
Regenerated fibres management by converting cotton based waste garment through regeneration processing into second
Lyocell lifetime cellulosic fibre. The approach will contribute to the reduction of both economic and environ-
Waste cotton garments mental impact of waste garments and better management of resources required for production of cotton
and synthetic fibres.
© 2015 Elsevier Ltd. All rights reserved.

1. Introduction The most common avenue of extending the usage of textiles

garments is through the export of second-hand clothing to Africa
The increasing number of fashion seasons in the retail market (DEFRA, 2006, 2009; Hawley, 2006a,b; Baden and Barber, 2005).
has led to shorter and shorter “lifetimes” for textiles garments and However the literature and economic logic suggest that this
an increase in discarded clothing associated with the changing “recycling route” adversely affects the local textile manufacturing
fashion. Accordingly the percent contribution of textiles within industry in Africa (Amankwah-Amoah, 2015; Hawley, 2006a,b;
municipal waste is increasing (DEFRA, 2006, 2009) and leading to Baden and Barber, 2005) and again is encouraging in developing
an increase in land fill tax (Ali and Courtenay, 2014). Therefore alternative approaches. Traditional mechanical recycling converts
there is need for exploring alternative solutions that are more the waste garments by pulling the fabric into yarns and fibres and
sustainable and lessen the environmental impact of waste textiles. then reconstituting back into either recycled yarns for textile ap-
Some of the alternatives for the recycling of cotton waste garments plications or into other applications such as nonwoven products,
involve conversion of the cotton based waste garments by various carpet underlay, sound insulators, thermal insulators, phase
methods into alternative renewable energy resources (Hong et al., change materials, geo-textile materials, odour removal material,
2012; Shen et al., 2013; Jeihanipour et al., 2010; Jeihanipour and filtration material, and many others (DEFRA, 2009). However the
Taherzadeh, 2009). While the approach of converting waste gar- mechanical recycling can only produce yarn with limited tex due
ments into renewable energy resources helps in reducing the to yarn breakage during spinning process (Lebedev, 1995) and
environmental impact of waste garments unfortunately there is no wider tex ranges could only be achieved by blending with virgin
reduction in the pressure on water and land requirements for the cotton fibres (Merati and Okamura, 2004). Some of standards and
production of cotton and synthetic fibres. specification for technical applications such as geo-textile pro-
hibits the use of mechanically recycled yarns regardless of its
physical performance (DEFRA, 2009). It is therefore obvious that
* Corresponding author. Present address: College of Engineering and Technology, the quality of the mechanically recycled textile material cannot be
University of Dar es Salaam, Dar es Salaam, Tanzania. the same as that of the first life cycle of the same material, hence
E-mail address: liberato.haule@udsm.ac.tz (L.V. Haule).
1 there is need to promote recycling by chemical conversion of the
Present address: School of Design, University of Leeds, Leeds LS2 9JT, UK.

http://dx.doi.org/10.1016/j.jclepro.2015.08.086
0959-6526/© 2015 Elsevier Ltd. All rights reserved.
4446 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451

waste garments into fibres for the second life cycle. The chemical 2. Material and methods
conversion of the waste garments into new fibres must consider
the separation of fibre blends and removal of finishes such as dyes 2.1. Methods
and other functional finishes which may hinder the conversion
process. 2.1.1. Preparation and purification of the fabrics
In order to overcome the environmental and economic impact In order to simulate the effect of extended washing during do-
of the waste textiles, a closed loop recycling technology is now mestic usage a 100% plain woven cotton fabric, 152 g/m2, was
being considered. The first attempt to recycle cotton based waste washed 50 times with ECE-phosphate based detergent in a Was-
garments by regeneration into fibres was patented by Firgo et al. cator FOM-71 machine, as previously reported (Haule et al., 2012),
(1997) where the process involved dissolution of the waste gar- and the fabric was the source material for deconstruction into pulp
ments in N-methylmorpholine N-oxide (NMMO) solution, spinning and spinning of regenerated lyocell, ReCell-1 fibres. Similarly in
and regeneration of the cellulose fibres. The physical properties of order to prepare crosslinked crease resistant fabrics the plain
the fibres were relatively higher than the other regenerated and woven cotton fabric was treated with 100 g/L DMDHEU easy care
cotton fibres. However in the Firgo et al. patent, no consideration finish (Haule et al., 2012). The easy care finished cotton fabric was
was taken for the effects of finishes such as dyes and easy care then Wascator washed 50 times with ECE-phosphate based deter-
finishes on the dissolution of the waste garments. Subsequently gent and subsequently purified in acid-alkali solution to produce a
Haule et al. have demonstrated that a typical easy care finish component source of the ReCell-2 fibres (Haule et al., 2014). The
applied to cotton garments is durable almost through the entire ReCell-2 fibres were prepared from a blend of 20% cellulose
first life cycle of the garment (Haule et al., 2012). Further work recovered after purification of the DMDHEU treated cotton fabrics
demonstrated that the easy care finish could also dramatically and 80% wood pulp. In order to prepare the waste indigo dyed
reduce the NMMO solubility of the cotton waste garments during denim garments for deconstruction into pulp for spinning, 5 pairs
fibre making process and the methods for removal of the easy care of indigo dyed waste denim were washed once with ECE-phosphate
finishes were optimized in order to establish viable commercial based detergent, tumble dried, zippers, buttons and threads
processing technology (Haule et al., 2014). Therefore this work removed manually and considered the source of ReCell-Denim
extends the previous work by studying the dissolution of the pu- fibres.
rified cotton waste garments in NMMO solution and subsequent
spinning into new fibres. 2.1.2. Deconstruction of the fabrics
The choice of NMMO solution as a solvent for the waste cotton The purified cotton fabrics were deconstructed into a pulp using
garments is due to the fact that the solvent can dissolve completely a laboratory Valley beater (Weverk 45486) with the fabrics/gar-
cellulose without any degradation, is 99% recyclable, safe to work ments hand-cut into 10
10 mm pieces prior to introduction into
with and safe in the environment in case of any spillages the beater deconstruction process. The parameters used in the
(Woodings, 1995). The dissolution of cellulose in NMMO solution is beating process were set in accordance with the Technical Associ-
achieved by constant mixing at increasing temperature and ation of Pulp and Paper Institutes (TAPPI) standards (TAPPI, 1996).
reduced pressure so as to dehydrate the tertiary mixture of NMMO, 360 g of fabric pieces was mixed in 23 L of water to obtain a con-
water and cellulose into cellulose-NMMO solution (Chanzy, 1982; sistency of 1.56%. The gap between beater roll and beater plate was
Chanzy et al., 1990; Kim et al., 2005). The dehydrated cellulose/ adjusted by putting a standard weight of 4.5 kg on the beater plate
NMMO solution is formed in a spinneret, stretched in an air gap and lever arm. After running the Valley beater for 90 min, the stock was
then the cellulose fibre is precipitated in any polar liquid which is a collected, drained and air dried for further tests.
non-solvent to the cellulose (Johnson, 1969; Firgo et al., 1997).
During the dissolution process care should be taken to ensure no 2.1.3. Determination of the molecular properties of the prepared
oxidation of the solvent occurs, in this case antioxidants are pulp
incorporated in the dissolution process. The process of dissolution The limiting viscosity of the pulps prepared from various types
of cellulose in NMMO solution and regeneration of fibres is known of material was determined as per the previously reported method
commercially as a lyocell process and the resultant fibres are (Haule et al., 2012). The viscosity average molecular weight (Mv) of
generically known as lyocell fibres. The lyocell fibres are charac- the fibres was calculated by determining the limiting viscosity and
terized by a high degree of orientation of the fibrils and weak using the MarkeHouwink relationship (Immergut and Eirich,
intrafibrillar hydrogen bonds resulting in the fibres being suscep- 1953), Equation (1).
tible to fibrillation under mechanical action and wet conditions
(Huong Mai et al., 2008; Zhang et al., 2005; Taylor, 1998). Although ½h ¼ Km ðMvÞa (1)
this tendency to wet fibrillation can make dyeing of lyocell fibres
more difficult, if controlled, fibrillation can introduce an attractive where Km and a are constants and for the CED solution are 1.33 and
appearance and appealing handle to garments made from the 0.9, respectively, and [h] is the limiting viscosity of the cellulose.
lyocell fibres (Bates et al., 2004, 2008; Goswami et al., 2007; Zhang
et al., 2005; Taylor, 1998). Additional beneficial features of the 2.1.4. Dissolution and spinning of fibres
lyocell fibres are the relatively high elasticity and regain that pro- In order to spin fibres the required spinning dope was prepared
vide shapeability and comfort to the garments. Overall the lyocell by mixing 300 g of 50% NMMO solution with 27 g pulp and 0.2 g n-
process is considered as an environmentally benign process and the propyl gallate using a laboratory scale mixer. The dissolution pro-
lyocell fibres have attractive mechanical and comfort properties. cess was made possible by mixing the pulp and NMMO solution at
Therefore in this paper the lyocell process was considered for increasing temperature and vacuum at suitable steps until the final
the regeneration of fibres from the 100% cotton waste garments spinning dope was composed of 9% cellulose, 13% water and 78%
from various sources. The cotton based waste garments were pu- NMMO. For every sample the dissolution dope was checked for
rified, dissolved and spun into fibres. The resultant properties of the fibre solubility using a light microscope. The fibres were then spun
recycled fibres such as molecular weight, density, tensile and Dy- from a laboratory scale spinning machine at Lenzing AG, Austria.
namic Mechanical Analysis (DMA) were determined and discussed The spinneret used had 19 holes of 100 mm in size and the spinning
with respect to the standard lyocell fibres. temperature was 115  C. The dope throughput was 0.03 g/min per
 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451 4447

hole, the air gap conditions were set at 30 mm, 24  C and 53%
relative humidity.
The winding speed was 25.1 m/min. and water was used to
precipitate the fibres. The fibres were then oven dried at 60  C
overnight.

2.1.5. Determination of linear density

The fibre linear density (L, in dtex) was calculated from the
relationship between the winding speed (Ws, in m/min), percent
cellulose in the spinning dope (cel) and the rate of extrusion of the
dope (Ds, in g/min) as per Equation (2):

Ds
L ¼ 121

cel (2)
Ws

Fig. 1. SEM micrograph of Lyocell fibres at 5000
magnification and an accelerating

2.1.6. Determination of fibre specific gravity voltage of 5 kV.
The density of the fibres was determined using a microbalance
(Metter Toledo density balance) with an accuracy of ±0.0001 g/cm3
and the liquid used was xylene (density 0.865 g/cm3 at 20  C). The ramp programme, with heating of 3.00  C/min from 25  C to 200  C
fibres were first weighed in air and then weighed in the xylene and testing carried out at constant static strain and a frequency of
liquid. The weight of the fibres in air (A) and in liquid (B) and the 1 Hz.
temperature of the immersion liquid were recorded. The density of
the immersion liquid at the recorded temperature was determined 2.1.9. Scanning electron microscopic (SEM) analysis
using Equation (3): The surface morphology of the fibres was investigated using a
Hitachi EDAX-S300N SEM instrument. The fibres were pre-gold
r0
rt ¼   (3) coated using a SEM E5100 system (Polaron Limited) which was
b Tf  20 þ 1 operated at 0.01 torr with current of 20.0 mA for 3 min. For all SEM
imaging the secondary electron (SE) detector and a 5 kV acceler-
where rt and ro are the densities of the xylene liquid during the test ating voltage was used.
and at 20  C temperature, respectively, b is the volumetric tem-
perature coefficient of xylene liquid (0.00086v/v C), Tf is the tem- 3. Results and discussion
perature of the xylene liquid during sample testing and then the
density of the fibres (r) was calculated as: 3.1. Surface morphology of the fibres by SEM

A The SEM micrographs for lyocell, ReCell-1, ReCell-Denim and

r¼ þ r2 (4)
ðA  BÞðrt  rz Þ ReCell-2 fibres, Figs. 1e4, indicated the surface of all the studied
fibres appeared to be smooth, with no surface fibrillar structure
where r2 is the density of air (0.0012 g/cm3). observed. However surface artefacts/contaminants were evident in
Ten replicates were measured and the mean was recorded. the micrographs and could arise due to fibre handling or general
processing.
2.1.7. Determination of tensile properties of the fibres
The tensile properties of the fibres were determined using an 3.2. Molecular properties of the fibres
Instron tester Series IX machine with the tested specimens either
pre-conditioned at 65% relative humidity and 23  C for 24 h or for Examination of the molecular properties of the fibres as deter-
the wet fibres pre-soaked in water for 2 h (British Standards, 1978). mined by viscometry indicated that the fibres regenerated from
The testing was carried out in a room conditioned at 65% relative
humidity and 23  C. The test methods for the fibres were in
accordance to the British standards (British Standards, 1978) and a
pre-tensioning of 0.5 cN/tex and crosshead speed of 10 mm/min
were applied to the fibres. For more effective analysis the ends of
the fibres specimens were glued to cardboard frames with epoxy
resin (Chae et al., 2002) and then clamped in the Instron jaws. From
the acquired data the mean tensile strength and elongation at break
were reported.

2.1.8. Determination of dynamic mechanical analysis (DMA)

properties
The variation in the mechanical properties of the fibres with
temperature was assessed by a DMA Q800 V7.5 instrument with
the clamp mode in tension for film and fibres. In order to ensure
firm clamping and minimum deformation of the specimen, the
ends of the fibres specimens were glued to cardboard frames with
epoxy resin and then introduced into the machine jaws (Chae et al., Fig. 2. SEM micrograph of ReCell-Denim fibres at 5000
magnification and an
2002). The analysis range was set with a standard temperature accelerating voltage of 5 kV.
4448 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451

In developing a commercial approach to the fibre processing,

blending of wood pulp and reclaimed cotton pulp (ReCell-2) was
evaluated and found to deliver an improvement in the molecular
properties of the resultant fibres to a level which is intermediate to
that of lyocell and the ReCell-1 fibres. For instance, a blend of 20%
cotton reclaimed pulp and 80% wood pulp could increase the
overall molecular mass of the fibres by 4% with respect to the
standard lyocell, Table 1 This would suggest that the pulp reclaimed
from waste cotton garments can be used to regenerate fibres with
properties similar to the fibres spun from 100% wood pulp.
Furthermore the blend between waste cotton and wood pulp could
result in fibres with similar properties.

3.3. Mechanical properties of the fibres

Fig. 3. SEM micrograph of ReCell-2 fibres at 5000
magnification and an accelerating Comparison of the mechanical properties of the fibres regen-
voltage of 5 kV.
erated from cotton-based waste garments and lyocell fibres,
Table 2, indicated that the cotton waste garments can be regener-
ated into ReCell fibres with a linear density almost equal to that of
the lyocell fibres. A feature of the ReCell-2 fibres was the lower
coefficient of variation in the linear density which may be due to
improved rheology of the blend pulp which formed into fibres
relatively easily, Table 2.
Examination of the dry tenacity of the fibres, Table 2, as
measured at conditioned state of 23  C and relative humidity of 65%
indicated that the tenacity was decreasing in the order of:

Recell­1 > ReCell­Denim > ReCell­2 > lyocell

The ReCell-1 and ReCell-Denim fibres had tenacity values which
were 40% and 22%, respectively, higher than the tenacity for lyocell
fibres. A blend of 20% cotton pulp and 80% wood pulp improved the
tenacity of the resultant fibres (ReCell-2) by 7% with respect to
lyocell fibres. The elongation at break of the conditioned fibres
Fig. 4. SEM micrograph of ReCell-1 fibres at 5000
magnification and an accelerating decreased in the order of lyocell > ReCell-2 > ReCell-
voltage of 5 kV. Denim > ReCell-1. The ReCell-1 and ReCell-Denim had elongation
at break which is 18% and 13%, respectively, less than the lyocell
fibres. Corresponding ReCell-2 fibres has an elongation at break of
cotton fabrics/garments have a higher molecular weight than the 12% less than the lyocell fibres. This indicated that blending of wood
standard lyocell fibres, Table 1. The average molecular masses of the pulp and reclaimed cotton pulp could produce fibres with higher
ReCell-1, ReCell-Denim and ReCell-2 fibres were 116%, 12% and 4%, tenacity and lower elongation at break than lyocell fibres. The
respectively, higher than the molecular mass of lyocell fibres. The variation in tenacity and extension at break among the fibres under
higher molecular masses of the ReCell fibres were due to the dif- investigation could be due to the differences in their molecular
ference in the corresponding molecular properties between the properties.
wood pulp and the pulp reclaimed from multiple washed cotton Examination of the dry modulus of the fibres indicated that the
waste garments as previously reported (Haule et al., 2014). fibres modulus decreased in the order of ReCell-1 > ReCell-
The low molecular mass of the ReCell-Denim fibres relative to Denim > ReCell-2 > lyocell, Table 2. The ReCell-1, ReCell-Denim and
the lyocell fibres was probably due to higher degradation of the ReCell-2 fibres moduli were 48%, 45% and 2%, respectively, higher
denim during its wash/wear lifetime when compared to the ReCell- than the modulus for lyocell fibres. Similarly examination of the
1 fibres which were produced from white cotton fabric that has stress/strain curves for both ReCell and lyocell fibres indicated that
only experienced extended laundering over 50 cycles. The densities the ReCell fibres have higher tenacity and modulus but lower
of all the regenerated fibres were similar. extension at break than the lyocell fibres, Fig. 5. This higher tenacity
and modulus could be due to the differences in the properties of the
initial reclaimed cotton and the virgin wood pulps and the rheology
properties of their respective spinning dopes. The limiting viscosity,
Table 1
Molecular weight and density of ReCell and Lyocell fibres. hence the degree of polymerization of the cellulose has been
identified an important parameter for the quality of spinning of
Fibre type Viscosity e average Density
fibres (Braverman et al., 1990; Fink et al., 2001). The reclaimed
molecular weight (g/cm3)
(Mv) [g/mol] cotton pulp had a higher DPv which gave a better molar mass
distribution of the cellulose during dissolution and spinning of fi-
Lyocell 494 1.51 ± 0.01
ReCell-1 1066 1.51 ± 0.01 bres than wood pulp. This resulted in high molecular weight fibres
ReCell-Denim 623 1.51 ± 0.01 and better structure formation of the cotton reclaimed pulp than
ReCell-2 (blend of 80% wood 517 1.51 ± 0.01 the wood pulp. The higher tenacity and modulus of the ReCell fibres
pulp and 20% reclaimed was mainly due to the higher molecular weight as indicated in
cotton pulp)
Table 1.
 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451 4449

Table 2
Tensile properties of Lyocell and ReCell fibres.

Fibre tensile properties Lyocell ReCell-1 ReCell-Denim ReCell-2

Mean CV Mean CV Mean CV Mean CV

Linear density (dtex) 1.3 9.4 1.3 8.8 1.3 9.1 1.3 4.3
Dry tenacity (cN/tex) 34.7 9.6 48.7 10.1 42.5 8.4 37.2 10.4
Wet tenacity (cN/tex) 28.8 8.8 42.4 14.6 35.2 12.5 32.6 8.1
Dry elongation (%) 11.2 14.1 9.2 14.1 9.7 13.4 9.9 17.1
Wet elongation (%) 13.2 14.0 11.0 13.6 14.2 18.6 14.1 17.1
Dry modulus (cN/tex) 205 144 303 109 298 85 210 71
Wet modulus (cN/tex) 112 89 152 56.0 162 90 116 55

Cv ¼ coefficient of variation.

A common feature of the mechanical properties of all the tested the greater cellulosic modification during their “first lifetime”
fibres was the unusual variability levels in the coefficient of varia- experience.
tion, Table 2, and this was possibly due to the methodology used to A comparison of tensile properties of the ReCell, lyocell and
mount the fibres for the tensile tests. Further work is underway to cotton (Cook, 1984; Bredereck and Hermanutz, 2005; Woodings,
improve this aspect of the fibre analysis. 1995; Taylor, 1998) fibres indicated that the tenacity of the ReCell
Re-examination of the wet properties of the ReCell and lyocell fibres was above that of cotton and standard lyocell, however the
fibres indicated that both fibres experienced a reduction in tenacity extension for ReCell fibres was intermediate between the cotton
and modulus and an increase in elongation at break when in the and lyocell values, Fig. 6. The observed extensibility performance of
wet state, Table 2. The two types of fibres have almost the same the ReCell fibres perhaps provides an opportunity in garment
level of reduction in the wet tenacity and modulus. In particular the making where the intermediate performance offers advantages
wet tenacity of the ReCell-1, ReCell-Denim and ReCell-2 fibres over both cotton and lyocell. The relatively higher tenacity of the
decreased by 13%, 17% and 12%, respectively, whereas the corre- ReCell fibres compared to the virgin cotton tenacity was probably
sponding properties for lyocell fibres decreased by 17%. In addition due to the fact that during purification and dissolution of the cotton
the wet modulus of the ReCell-1, ReCell-Denim, ReCell-2 and lyocell waste garments, the “degraded and modified” oligomers and
fibres decreased by 50%, 46%, 45% and 45%, respectively. The polymers also dissolve into the precursor cellulosic dope but during
elongation at break of the wet ReCell-1, and lyocell fibres was subsequent spinning of the dope into fibres these weakened cel-
reduced by 20% and 18%, respectively, whereas that of ReCell- lulose molecules were not reconstituted into the cellulosic fibres.
Denim, ReCell-2 fibres decreased by 46% and 42%, respectively. Hence the fibres are relatively free from polymeric “defects” and
The deterioration of mechanical properties of the regenerated fi- offer the ability to bear higher tensile loads.
bres in the wet swollen state was due to the weakening of the
cellulosic inter-polymer chain hydrogen bonding fibres in water. 3.4. DMA analysis of the fibres
When cellulose fibres are swollen in water, the polar water in-
teracts with the hydroxyl groups of the amorphous faction of the The DMA technique was used to assess the effect of temperature
cellulose, which disrupt the inter-hydrogen bonding in the cellu- on the mechanical properties of the ReCell-1, ReCell-2 and ReCell-
lose hence reducing the fibres ability to bear loads and increases Denim fibres and their properties compared with the standard
the elongation at break of the fibres. The nature of the relatively lyocell fibres. The specimen was heated at constant rate of
high reduction in elongation at break of the wet ReCell-Denim and 20e200  C and during the heating the specimen was deformed at
ReCell-2 fibres is uncertain at present but is probably a reflection of constant strain under a frequency of 1 Hz.
A comparison of storage modulus of the fibres at increasing
temperature indicated that the fibres reclaimed from cotton waste

Fig. 6. Comparison of extension at break (C) and tenacity (A) of ReCell, Lyocell and
cotton fibres. The cotton figure values are literature-based (Cook, 1984; Bredereck and
Fig. 5. Stress/strain curves for >-Lyocell and B-ReCell-1 fibres (each 1.33 dtex). Hermanutz, 2005; Woodings, 1995; Taylor, 1998).
4450 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451

garments have higher storage modulus that the lyocell fibres, the second hand clothing at the destination countries. Coupled to
however they all showed a similar rate of change of storage the export of second hand clothing is the more fundamental chal-
modulus with temperature especially in the temperature ranging lenge of production of cotton and synthetic fibres and better utili-
from 20  C to 140  C, Fig. 7. zation of dwindling land and water resources. Therefore this paper
The higher storage modulus for the fibres regenerated from proposes an alternative approach to fibre resource management
waste cotton garments was related to its relatively higher degree of and the development of technology to convert cotton-based waste
polymerization. The similarity in the slopes of the storage mod- garments through regeneration processing into second lifetime
ulietemperature curves for the ReCell fibres and lyocell fibres was cellulosic fibres.
mainly due to the similarity in their dissolution and physical Future work will focus on the characterization of fibres regen-
spinning conditions. erated from waste cottons in order to provide information on the
Therefore it can be concluded that the DMA results highlighted structure/properties of the fibres and their associated processing
the similar behaviour between the ReCell fibres derived from cot- performance.
ton waste garments and the standard lyocell fibres in terms of the
response of the mechanical properties of the fibres to deformation
at increasing temperature. Hence it appears the new ReCell fibres Acknowledgements
can withstand processing conditions similar to those of lyocell
fibres. We gratefully recognise the financial sponsorship from the
Tanzanian Gatsby Trust and the technical support of Lenzing,
3.4.1. Conclusions Austria, in furthering these research studies.
The pulps prepared from a range of typical “used” cotton fabrics
were successfully dissolved in NMMO solution and spun into fibres.
The molecular and mechanical properties of the fibres were References
determined and compared to the standard lyocell fibres. Their
Ali, M., Courtenay, P., 2014. Evaluating the progress of the UK's material recycling
molecular properties indicated that, the fibres spun from cotton
facilities: a mini review. Waste Manag. Res. 32 (12), 1149e1157. http://
waste garments have higher molecular weight and specific gravity dx.doi.org/10.1177/0734242x14554645.
than standard lyocell fibres. Furthermore results indicated that the Amankwah-Amoah, J., 2015. Explaining declining industries in developing coun-
ReCell type fibres have higher tensile properties and exhibited tries: the case of textiles and apparel in Ghana. Compet. Change 19 (1), 19e35.
http://dx.doi.org/10.1177/1024529414563004.
better wet strength recovery than the comparable lyocell fibres. Baden, S., Barber, C., 2005. The Impact of Second-hand Clothing Trade on Devel-
DMA studies indicated the storage modulus of the regenerated oping Countries, Oxfam, Oxford. http://policypractice.oxfam.org.uk/
fibres decreased with temperature. The ReCell type fibres exhibited publications/the-impact-ofthe-secondhand-clothing-trade-ondeveloping-
countries-112464 (accessed 04.06.14.).
relatively higher initial storage moduli than the lyocell fibres due to Bates, I., Maudru, E., Phillips, D.A.S., Renfrew, A.H.M., Su, Y., Xu, J., 2004. Cross-
the higher molecular weight of the precursor pulp material. linking agents for the protection of lyocell against fibrillation: synthesis,
It is clear from this preliminary study that the waste cotton application and technical assessment of 2,4-diacrylamidobenzenesulphonic
acid. Color. Technol. 120 (6), 293e300.
fabrics stripped of the easy care finish and indigo dyed waste denim Bates, I., Ibbett, R., Reisel, R., Renfrew, A.H.M., 2008. Protection of lyocell fibres
can be regenerated into fibres with mechanical, thermal- against fibrillation; influence of dyeing with bis-monochloro-s-triazinyl reac-
emechanical and surface properties similar to the lyocell fibres. tive dyes. Color. Technol. 124 (4), 254e258.
Braverman, L.P., Romanov, V.V., Lunina, O.B., Belasheva, T.P., Finger, G.G., 1990.
Furthermore the results indicate that the pulp reclaimed from
Rheological properties of concentrated cellulose solutions in N-methyl-
cotton based waste garments can be blended with wood pulp to morpholine-N-oxide. Fibre Chem. 22 (6), 397e400. http://dx.doi.org/10.1007/
make fibres with properties similar to lyocell. bf00632892.
Bredereck, K., Hermanutz, F., 2005. Man-made cellulosics. Rev. Prog. Color. Relat.
The overall aim of this paper was to develop a recycling tech-
Top. 35 (1), 59e75.
nology that will reduce the increasing environmental impact of British Standards, 1978. The Determination of Tensile Elastic Recovery of Single
waste cotton garments. Currently the garment lifetime is extended Fibres and Filaments (Constant-Rate-of-Extension Machines) (BS 4029:1978).
by recycling and exporting as second hand clothing for reuse in Chae, D.W., Chae, H.G., Kim, B.C., Oh, Y.S., Jo, S.M., Lee, W.S., 2002. Physical prop-
erties of lyocell fibers spun from isotropic cellulose dope in NMMO mono-
developing countries. However this current “export for reuse op- hydrate. Text. Res. J. 72 (4), 335e340. http://dx.doi.org/10.1177/
tion” is not sustainable due to the recognized negative impacts of 004051750207200410.
Chanzy, H., 1982. Celluloseeamine oxide systems. Carbohydr. Polym. 2, 229e231.
Chanzy, H., Paillet, M., Hage
ge, R., 1990. Spinning of cellulose from N-methyl
morpholine N-oxide in the presence of additives. Polymer 31 (3), 400e405.
Cook, J.G., 1984. Handbook of Textile Fibres: II. Man-Made Fibres, fifth ed. Merrow
Publishing Co. Ltd, Durham.
DEFRA, 2006. Recycling of Low Grade Clothing Waste. Department for Environment,
Food and Rural Affairs, London. http://www.oakdenehollins.co.uk/pdf/Recycle-
Low-Grade-Clothing.pdf (accessed 04.06.14.).
DEFRA, 2009. Maximising Reuse and Recycling of UK Clothing and Textiles. The
Department for Environment, Food and Rural Affairs-UK, London. http://randd.
defra.gov.uk/Document.aspx?Document¼EV0421_8745_FRP.pdf (accessed
20.10.13.).
Fink, H.P., Weigel, P., Purz, H.J., Ganster, J., 2001. Structure formation of regenerated
cellulose materials from NMMO-solutions. Prog. Polym. Sci. 26 (9), 1473e1524.
Firgo, H., Eichinger, D., Eibl. M., February 11, 1997. Process for the Production of a
Cellulose Moulded Body. U.S Patent 5,601,767.
Goswami, P., Blackburn, R.S., Taylor, J., Westland, S., White, P., 2007. Dyeing
behaviour of lyocell fabric: effect of fibrillation. Color. Technol. 123 (6),
387e393.
Haule, L.V., Rigout, M., Carr, C.M., Jones, C.C., 2012. Surface and bulk chemical
analysis of the durability of an easy care finish on cotton. Cellulose 19 (3),
1023e1030. http://dx.doi.org/10.1007/s10570-012-9672-x.
Haule, L.V., Carr, C.M., Rigout, M., 2014. Investigation into the removal of an easy-
care crosslinking agent from cotton and the subsequent regeneration of
Fig. 7. Storage modulus of A-ReCell-Denim, C-ReCell-1, ▫-ReCell-2 and B-Lyocell lyocell-type fibres. Cellulose 21 (3), 2147e2156. http://dx.doi.org/10.1007/
fibres with increasing temperature. s10570-014-0225-3.
 L.V. Haule et al. / Journal of Cleaner Production 112 (2016) 4445e4451 4451

Hawley, J.M., 2006a. Digging for diamonds: a conceptual framework for under- Kim, D.B., Pak, J.J., Jo, S.M., Lee, W.S., 2005. Dry jet-wet spinning of cellulose/
standing reclaimed textile products. Cloth. Text. Res. J. 24 (3), 262e275. http:// N-methylmorpholine N-oxide hydrate solutions and physical properties
dx.doi.org/10.1177/0887302x06294626. of lyocell fibers. Text. Res. J. 75 (4), 331e341. http://dx.doi.org/10.1177/
Hawley, J.M., 2006b. Textile recycling: a system perspective. In: Wang, Y. (Ed.), 0040517505054852.
Recycling in Textiles. Woodhead Publishing Limited, Cambridge, pp. 7e13. Laboratory Beating of Pulp (Valley Beater Methods):T200sp-96, 1996. TAPPI
€
Hong, F., Guo, X., Zhang, S., Han, S.-F., Yang, G., JOnsson, L.J., 2012. Bacterial cellulose (accessed 2010.).
production from cotton-based waste textiles: enzymatic saccharification Lebedev, N.A., 1995. Use of natural and chemical fibre wastes in production of mixed
enhanced by ionic liquid pretreatment. Bioresour. Technol. 104 (0), 503e508. yarns (a review). Fibre Chem. 27 (1), 52e54.
http://dx.doi.org/10.1016/j.biortech.2011.11.028. Merati, A.A., Okamura, M., 2004. Producing medium count yarns from recycled fi-
Huong Mai, B., Anelise, E., Thomas, B., 2008. Pilling in man-made cellulosic fabrics, part bers with friction spinning. Text. Res. J. 74 (7), 640e645. http://dx.doi.org/
1: assessment of pilling formation methods. J. Appl. Polym. Sci. 110 (1), 531e538. 10.1177/004051750407400715.
Immergut, E.H., Eirich, F.R., 1953. Intrinsic viscosities and molecular weights of Shen, F., Xiao, W., Lin, L., Yang, G., Zhang, Y., Deng, S., 2013. Enzymatic saccharifi-
cellulose and cellulose derivatives. Ind. Eng. Chem. 45 (11), 2500e2511. http:// cation coupling with polyester recovery from cotton-based waste textiles by
dx.doi.org/10.1021/ie50527a039. phosphoric acid pretreatment. Bioresour. Technol. 130, 248e255. http://dx.doi.
Jeihanipour, A., Taherzadeh, M.J., 2009. Ethanol production from cotton-based org/10.1016/j.biortech.2012.12.025.
waste textiles. Bioresour. Technol. 100 (2), 1007e1010. http://dx.doi.org/10. Taylor, J., 1998. Tencel e a unique cellulosic fibre. J. Soc. Dye. Colour. 114 (7e8),
1016/j.biortech.2008.07.020. 191e193.
Jeihanipour, A., Karimi, K., Niklasson, C., Taherzadeh, M.J., 2010. A novel process for Woodings, C.R., 1995. The development of advanced cellulosic fibres. Int. J. Biol.
ethanol or biogas production from cellulose in blended-fibers waste textiles. Waste Macromol. 17 (6), 305e309.
Manag. 30 (12), 2504e2509. http://dx.doi.org/10.1016/j.wasman.2010.06.026. Zhang, W., Okubayashi, S., Bechtold, T., 2005. Fibrillation tendency of cellulosic fi-
Johnson, D.L., 1969. Compounds Dissolved in Cyclic Amine Oxides. United States/ bers e part 4. Effects of alkali pretreatment of various cellulosic fibers. Carbo-
Rochester Patent 3,447,939. hydr. Polym. 61 (4), 427e433.