Field of the invention
The present invention is related to chenille yarn and woven
fabric. These are provided with a so-called pile, i.e. upright fibres offering the
fabric its velvety appearance. The invention is related to a specific kind of pile
yarn meant for the manufacture of such woven fabric as well as the woven fabric
itself.
State of the art
Furniture fabrics are woven or knitted textiles that are
used for the upholstery of seating furniture. A distinction can be made between
velvet woven fabrics and flat furniture fabrics. Velvet woven fabrics are produced
on wire looms, face-to-face weaving looms or by alternative processes, such as flock.
Flat woven fabrics, however, are accomplished through classic weaving looms.
As compared to velvet woven fabrics, the majority of flat
furniture fabrics have a limited wear-resistance. The furniture fabrics' wear-resistance
is usually tested according to the EN 14465 or BS2543 standard and is expressed
in a number of cycles "martindale".
Chenille furniture fabrics are flat furniture fabrics,
for which chenille yarns are used as wefts. A chenille yarn consists of a core yarn
that, in its turn, consists of at least two yarns, which are twined around each
other and in between which a chenille pile, i.e. a short pile yarn, is jammed. This
chenille pile is obtained by winding a yarn around a flat two part body, between
which a circular rotating blade revolves. By means of drive wheels to the body's
left and right, the yarn is driven onto the circular rotating blade, so that a pile
layer arises at both sides of the body. At the pile layer's left and right sides,
a core thread is carried along, which is twined as soon as the pile is cut. The
twining of the core yarns anchors the pile and thus the chenille yarn is created.
Frequently used textile fibres in the chenille yarns' chenille
pile consist of acrylic, viscose, cotton, polyester or polypropylene fibres. Hence,
these chenille yarns are pile yarns that provide the flat woven fabric with its
pile character. The use of chenille yarns in flat woven fabrics generally has a
positive influence on their wear resistance.
So as to obtain furniture fabrics with a shiny aspect,
chenille yarns of which the pile consists of either acrylic or viscose are generally
used.
With respect to flammability, a distinction has to be made
between the usual dry spun acrylic, being a copolymer that consists of acrylonitrile
for at least 85%, and modacrylic, which comprises between 85 and 35% of acrylonitrile.
Modacrylic also includes a substantial amount of halogenic compounds. Adding an
Antimony Compound to modacrylic can further improve its fire resistance. Chenille
yarns with a pile made of plain acrylic, however, do not sufficiently resist fire
(no fire retarding). The LOI index, being a measure for a material's fire resistance,
is situated between 18 and 20 for plain acrylic, between 25 and 30 for modacrylic,
and modacrylic with antimony has a LOI value situated between 28 and 36. PVC fibres
have an even higher LOI value, namely 35 - 40, but they are hard to dye and weave.
Textile materials containing a sufficient amount of modacrylic
combined with a certain amount of cellulose fibres (cotton or viscose fibres) do
have excellent fire resisting features and meet the current fire standards. They
have, nevertheless, a weak abrasion resistance and additionally reveal a lifeless
and dull aspect when compared to dry spun acrylic.
For specific markets, mainly the British market, furniture
fabrics for residential use have to meet certain fire behaviour requirements for
seating furniture (cfr. British BS 5852 part 1 standard; ignition sources 0 & 1
- cigarette & match), and are therefore always tested in combination with a foam.
An adequate fire resistance (fire retarding feature) can, amongst others, be obtained
through:
- the combined use of a non-fire resistant furniture fabric with a fire resistant
interliner; this interliner may either be laminated with the furniture fabric or
not. Such fabric must contain at least 75% of natural materials or viscose.
- the use of a fire resistant furniture fabric of which the fire retarding effect
is obtained through a fire resistant coating being applied at the back of the furniture
fabric. Frequently used coatings are foamed acrylates to which substantial amounts
of fire retarding additives have been added.
- the use of a fire resistant furniture fabric for which fire retarding textile
fibres are used.
Option 1 is significantly more expensive than the other options due to the use of
both a woven fabric and an interliner. Additionally, the requirement as to composition
prevents many furniture fabric constructions from being applied. Consequently, this
solution is rarely applied in practice.
Option 2 has as a disadvantage that, due to the FR coating layer being applied,
the furniture fabric loses, to a considerable degree, both its elasticity and the
comfort linked thereto.
Option 3 can only be applied by putting in certain specific fibres such as modacrylic
or PVC. These fire retarding fibres, however, have only a limited wear resistance
and lend a lifeless aspect to the furniture fabric.
Furniture fabrics for public use must meet other, more
rigid standards. In Great-Britain BS5852 Part 2 is applicable to this end, a standard
that is often used in other countries as well. So as to meet this standard, many
fabrics are often coated with fire resistant latex. The standard is, however, so
rigid that a considerable number of fabrics cannot be treated, or that the treatment
will not guarantee that they will meet the standard repeatedly. As these fabrics
have to comply with very strict criteria as to their abrasion resistance, the use
of 100% modacrylic as pile yarn (as well in chenille woven fabric as in pile woven
fabric) is subject to many restrictions and non-optimal.
Patent US6107218A relates to a chenille yarn and a method
for producing such chenille yarn. This chenille yarn is equipped with a core yarn
consisting of at least two components, namely a low-melting and a high-melting core
yarn. During the production process, the low-melting core yarn is melted and thus
anchors the chenille pile in the yarn. This type of solution has the advantage that
the pile is anchored in a better way, but it does not render the pile yarn itself
any stronger. Additionally, this solution requires the use of an expensive melt
yarn.
Aim of the invention
The aim of the invention is to produce a pile woven fabric,
which meets specific standards as to fire behaviour, wear-resistance, and which,
in addition, has an aspect that is both lively and full.
Summary of the invention
The invention concerns a chenille yarn and a chenille woven
fabric, as is described in the appended claims.
The present invention hence in the first instance relates
to a chenille yarn, of which the pile consists of an intimate mixture of two kinds
of fibres, one kind of fibre having fire-resisting properties. This type of chenille
pile (i.e. the short pile yarn being jammed between the core yarns during the production
of chenille yarn) is obtained by mixing both components when opening the fibres
before spinning takes place, this being the first stage of the spinning process
in which the fibres of various bales are brought together and in which the rather
compact piling of the fibres is rendered lighter. A second possibility consists
in mixing the different components during the processing of the slivers on the drawing
frames. During this process the fibres are stretched and more thoroughly mixed,
and the slivers' width is adjusted for spinning.
According to the invention, the pile of the chenille thread
consists of an intimate mixture of acrylic as a non fire-resistant material and
modacrylic as fire-resistant material, the portion of modacrylic in the pole being
situated between 50% and 85%. If the portion of modacrylic is smaller than 50%,
the pile yarn's fire-resistance capacity is insufficient. When the modacrylic portion
exceeds 85%, the wear-resistance is insufficient, and the woven fabric will have
an insufficiently lively aspect. The core yarns that jam the chenille pile can either
consist of 100% fire resistant, non-fire resistant or a mixture of both in any proportion.
The core yarns can be made of the same material as the pile yarn, i.e. of the same
mix of acrylic/modacrylic, the modacrylic portion being situated between 50% and
85%. Alternatively, the core yarns exclusively consist of modacrylic. According
to a particular embodiment, the core yarns consist of a non-fire retarding material
(e.g. regular acrylic) so as to optimize the final product's construction from a
price economic point of view, and since they are anyhow protected by a pile yarn
coat around the core yarns. Finally, the core yarns can be made of other materials
(e.g. cellulose).
It was established that a furniture fabric that was produced
using this yarn, still meets the BS5852 standard, and, moreover, demonstrates an
excellent abrasion resistance as well as a lively aspect. Additionally, the mixture
of acrylic and modacrylic fibres in the pile yarn allows a reduction of the cost
price.
The method for producing chenille yarn according to the
invention does not differ from the known production methods. It suffices to apply
one of these methods while using the above mix of, preferably, modacrylic and acrylic
fibres.
A second production method according to the invention consists
in a so-called 'pile woven fabric', which is not made from chenille yarn but by
means of a technique characterised by the creation of yarn loops during weaving,
the latter being either subsequently cut, thus causing upright fibres that do also
form a 'pile' to appear, or not cut, so that a corduroy fabric is created. In this
method, the pile or loop yarn is formed by a yarn that consists of a mix of acrylic
and modacrylic fibres comprising a portion of modacrylic fibres between 50% and
85%. This type of yarn is obtained by mixing both components while the fibres are
opened, before spinning takes place, this being the first stage of the spinning
process, which involves bringing together the fibres from various bales, and during
which the rather compact piling of fibres is rendered lighter. A second possibility
consists in mixing the different components while the fibre ends are treated on
the stretch units; this process involves stretching the fibres and mixing them more
thoroughly, and adjusting the fibre ends' width for spinning. If the portion of
modacrylic fibres is smaller than 50%, then the pile yarn's fire-resistance capacity
is insufficient. When the modacrylic portion exceeds 85%, the wear-resistance is
insufficient, and the woven fabric will have an insufficiently lively aspect.
Detailed description of a specific use of the invention
The article Godiva from Escolys Textiles, is woven on a
polyester chain (PES ring spun Ne 20/2 with 37 threads per cm) and uses 700 wefts
of acrylic chenille (Nm 4.85) a meter, 700 wefts open end spun cotton (Ne 6A/1)
a meter and 700 wefts polyester continuous filament (2*167dtex) a meter. In order
to render the article fireproof in accordance to BS5852 Part 1, the fabric has to
be treated with fire retarding latex.
However, if the chenille is replaced by a chenille thread
of which the pile consists of an intimate mixture of acrylic and modacrylic in a
proportion of 1/3, 2/3 with an Nm 3.75, and half of the open end spun cotton by
a Modacrylic thread Nm 10/l, then a woven fabric containing a sufficiently high
abrasion, which is fire resistant according to BS5852 Part 1; Ignition sources 0
& 1 (cigarette and match) and which has a lively and attractive aspect.
Comparative tests have been carried out on furniture fabric
of the Godiva quality with respect to the regular BS 2543 standard for abrasion
resistance of woven fabrics,. According to this standard, the fabric must withstand
at least 20000 'Martindale' cycles. The fabric of which the chenille pile consists
of 100% modacrylic failed after 16000 cycles. The one of which the chenille pile
consists of a mixture of modacrylic and acrylic, according to the invention, withstood
the required 20000 cycles.
The Godiva variant's fire resistance was also measured
in relation to the BS5852; part 1, ignition source 0 and 1 standard.
Source 0 relates to burns by a cigarette. For each tested Godiva variant consisting,
according to the invention, of a mixture of acrylic and modacrylic fibres in the
pile, the following results were achieved:
Source 0 (cigarette): damage is limited to scorch marks limited to the locations
where the cigarette had touched. The cigarette was extinguished after ± 21
minutes. The fabric did neither show any progressive inflammation nor did it show
any smouldering.
Source 1 (Butane gas flowing at 45ml/min at 25°C):
burning stopped 1 second after the burner had been turned down. No progressive smouldering
was established.
Conclusion: the furniture fabric consisting of a chenille
pile according to the invention, does indeed meet the fire resistance requirements,
despite its lower modacrylic fibre content. As, with respect to Source 1, the standard
requires burning to stop within 120 seconds, the 1 second continued burning time
is a very reliable result.
In relation to Source 0, the applicable continued burning
time according the standard is one hour. For this case, the standard is amply met
as well.