The dyeing of nonwoven fabrics part 1: Initial studies
, A.D. Hewitt, R.S. Blackburn, S.J. Russell
University of Leeds, Leeds LS2 9JT, UK
Received 2 August 2011
Accepted 15 September 2011
Available online 22 September 2011
The extents of uptake of 0.5e15% of two disperse dyes on woven, knitted and hydroentangled nonwoven
poly (ethylene terephthalate) fabrics were compared. The colour strength of the dyeings followed the
order: nonwoven > knitted > woven. Differences in surface reﬂection were not responsible for the
observed dye uptake behaviour, as the PET ﬁbres used in the construction of the nonwoven, knitted and
woven fabrics were of similar cross-sectional and longitudinal dimensions. The degree of PET fabric
crystallinity could not explain the observed differences in colour strength and comparable melting
temperatures were obtained for the three PET compositions. The rate of uptake of C.I. Direct Red 89
followed the order: nonwoven > knitted > woven cotton and also the colour strength of two direct dyes
followed the order: nonwoven > knitted > woven and, in doing so, concurred with that of the two
disperse dyes on the three types of PET fabric. The uptake of both disperse and direct dyes as a function
of time was neither ﬁbre- nor dye-related but was dependent upon some function of fabric construction.
It was suggested that fundamental differences in ﬁbre arrangement and porosity in woven, knitted and
nonwoven fabrics resulted in differences in accessibility to dye molecules, according to which, whilst dye
molecules may gain uniform access to all interior ﬁbre surfaces in a hydroentangled nonwoven structure,
only the outermost ﬁbres within a yarn-based structure might be readily accessible. This was supported
by the calculated porosity values for each undyed fabric type which followed the order:
nonwoven > knitted > woven for both cotton and PET fabrics, which ﬁtted well with the colour strength
order: nonwoven > knitted > woven.
Ó 2011 Elsevier Ltd. All rights reserved.
The term ‘nonwoven fabric’, which is usually shortened to
‘nonwoven’, refers to an assembly of individual ﬁbres or ﬁlaments
that are bonded by means of friction and/or cohesion and/or
adhesion [1e4]; as such, nonwovens differ fundamentally from
conventionally manufactured woven or knitted fabrics insofar as
they are typically not based on intermeshed or interlaced yarns.
Since, in the manufacture of nonwovens, yarn spinning is absent, as
are the subsequent processing steps such as knitting and weaving,
nonwoven production is characterised by high production rates and
low cost. Nonwoven production and deliveries for the Greater
Europe region (Western, Central and Eastern Europe, Turkey and
Commonwealth and Independent States) has reached >1.6 million
tonnes and manifold applications include single use liquid absor-
bent hygiene products, representing over one third of total
production as well as durable products such as geosynthetics,
ﬁlters, home furnishings, synthetic leather, automotive headliners
and ﬂoor coverings . There are various manufacturing routes for
nonwovens [2,4], which, in essence, depend on whether the pre-
cursor web comprises continuous ﬁlament (spunbond) [1,6] or
staple ﬁbre  and, in the latter case, whether it is formed either by
dry (dry-laid)  or wet (wet-laid)  techniques; the ensuing can
be bonded mechanically , thermally  or chemically  to
produce the nonwoven fabric.
Whilst the majority of natural and synthetic ﬁbres are
compatible with nonwoven fabric manufacture, synthetic polymer
materials predominate  and, in particular, polypropylene (PP)
[2,12] from both a low cost perspective and also because of the
particular technical requirements of the product. Despite steady
growth in production, nonwovens comprised only 9.9% of the
72.5 Â 10
tonnes of textile ﬁbre that were consumed in 2007 .
Although globally, apparel constitutes >25% of ﬁbre consumption
, from a nonwovens perspective, apparel usage is mostly
conﬁned to disposable protective garments, synthetic leather as
well as linings and interlinings . For nonwovens to be employed
in apparel, aside from the aesthetic and attritional properties, as
well as marketing considerations, which are outside the scope
of this study, nonwoven articles need to be dyed to depths of shade
which exhibit levels of fastness to repeated laundering,
Corresponding author. Tel.: þ44 0 113 343 3698; fax: þ44 0 113 343 3704.
E-mail address: firstname.lastname@example.org (S.M. Burkinshaw).
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Dyes and Pigments
journal homepage: www.elsevier.com/locate/dyepig
0143-7208/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
Dyes and Pigments 94 (2012) 592e598