Industrial Textiles – successfully following new trends

4
Fibers & Filaments
In focus
Industrial Textiles – successfully
following new trends
Industrial textiles are the great white hope of the classical textile nations following China’s
ascent to the position as the world’s largest apparel manufacturer. They are the innovation drivers for many small and medium-sized companies throughout the world.
by Jutta Stehr and Jürgen Vogel
Industrial textiles fill those areas of application that nobody had even considered 10 or even just 5 years ago. All in
all, they are therefore an important reason that the ancient craft of textiles is
still very much alive and active.
The field of industrial textiles comprises such diverse products as fishing
nets and sacks, protective clothing and
sails, vehicle tarpaulins and artificial skin
or more commodity products like tarpaulins, safety-belts, conveyor / transmission
belts, hoses, ropes, nets and tire-cord.
One area enjoying increasing popularity of late is geotextiles. One reason for
this is advancing global industrialization,
which would be inconceivable without
the expansion of local infrastructures,
and in particular roads. Large countries
such as India, Russia and China are
already carrying out, or plan to do so,
major projects for improving their infrastructures, with the consequence that
the geotextiles sector can look forward
to a promising future.
Geotextiles are permeable fabrics (for
example, jute and coconut) and synthetic fabrics (geosynthetics). They have the
ability to separate, drain, filter, reinforce,
seal and protect against erosion.” [1]
In industrialized nations, the use of
geotextiles in road construction has
been standard for several decades. In
1926, engineers started using cotton
fabrics for strengthening sidewalks in
the US. In 1960, needle punched nonwoven fabrics were first used in the US
to strengthen roads. [2]
Today, there are various customized
products available for the most varied
applications, made from both manmade
and natural fibers. One of these highlyspecialized products is geogrids, for ex-
ample woven or non-woven and coated
structures made from high-modulus
polyester filaments. Geogrids are used
to improve the stability and strength of
soft, poorly load-bearing ground and
slopes both for asphalt roads and unsupported construction sites and forest
paths. Bridging critical points using geogrids is often less expensive and more
durable than conventional measures
such as replacing the soil or installing
stabilizing pylons.
Stronger with Industrial Textiles
Furthermore, geogrids can be used for
reinforcing dams and embankments in
road and railway construction. Geogrids
are gentle of resources as they permit
the building of stable, precipitous embankments. At the same time, they are
denier range: 4 x 1500 den
4 x 2000 den
4 x 3000 den
2 x 6000 den (finally to be tested)
durable as they generally have a lifecycle of several decades.
The starting product for geogrids is
industrial polyester yarns with medium
titers of between 2000 and 3000 denier.
As they need to be able to absorb high
tensile forces, in other words stretch only
minimally when subjected to loads, the
multifilaments must have a high degree
of dimensional stability, in other words a
high modulus of elasticity.
The yarns are plied into bundles and
woven or made into wide-meshed grids
using warp-knitting technology. The
mesh width varies depending on the
requirement, but lies between 15 and
30 mm in the case of most commercial
geogrids. In sandy grounds, this open,
tensile structure is interlaced with the
ground or the fill, hence increasing the
load bearing capacity.
4 x 1500 den (on one winder)
4 x 2000 den (on one winder)
4 x 3000 den (on one winder)
2 x 6000 den (on one winder) (finally to be tested)
8 x 1000 den (on one winder) (finally to be tested)
8 x 1500 den (on one winder) (finally to be tested)
Remark: for whole product program add. modification parts might be required
Super-heavy denier yarn machine up to dtex 13,300
In focus
In a final step, the polyester grid is
coated. A PVC mantle provides grids with
stability and long-term protection against
mechanical damage and aggressive
soils. For asphalt surfacing applications,
the coating reinforces the adhesion of the
geogrids between the layers of asphalt by
means of a bitumen emulsion.
The end applications for geotextiles
demand the highest quality of the individual links within this process chain.
The, to date, parallel and completely
independently-existing production processes of yarn manufacturers and geotextile producers, sacrifices huge potential in terms of quality and margins.
Integrated production – from the raw
material to the finished product, not
available to date – provides the perfect
solution for this market niche.
Total solutions for Industrial Yarns
Oerlikon Barmag Engineering is world
premiering its complete system for geogrids. Starting with solid state postcondensation (SSP) and its spinning
plants all the way through to the coating
machine, the global market leader for
textile and industrial filament solutions
spinning systems offers manmade fiber
solutions from a single source.
One example for the solutions offered
from Oerlikon Barmag is our heavy denier
and super heavy denier machine concept
which is designed to produce up to dtex
13,300 per winding position which for the
time being is not covered by any other
machine/technology supplier.
These lines can produce such deniers as dtex 2,200, 3,300, 4,400 and
6,600. Beside the primary application in
the geotextile or geogrid reinforcement,
the yarn is also used for lifting slings,
ropes, etc. Such applications mainly
require high-tenacities and adhesive
finishes. One of the main advantages is
that such heavy deniers can be simultaneously produced on the spin-drawing
winding machine without later plying in
a further, downstream process.
The depicted process (HT/LS 7) represents the super-heavy denier machine
concept for the production of up to dtex
13,300 per winding position. This ma-
Fibers & Filaments
5
At work: Industrial Yarn machines spinning super-heavy denier yarns
chine is equipped with one 4-end winder
(ACW 4l-1200/4) per position featuring
a package stroke (width) of 250 mm.
With this machine concept, 4 times dtex,
1,670-3,300 or 2 times dtex 6,600 per
winding position can be produced.
By adding another 4-end winder (HT/
LS 8), it is possible to produce 8 times
dtex 1,100 and even 1,670 of conventional high-tenacity products in order to
utilize the full extrusion and spinning capacity of this machine design.
A general, super-heavy denier machine consists of four winding positions
in the smallest of spaces and delivers
a nominal annual production capacity
of approx. 8,000 tons. Therefore, such
machines guarantee the lowest conversion costs in connection with an extremely economical investment.
In order to meet the high drawing
and shrinkage forces needed for these
products, this machine is equipped with
Oerlikon Barmag’s latest godet development, the HFpower (HFp) godet.
Power godets for high-denier
Industrial Yarns
The latest development of the HF godet
series, the HFp godet, combines an
extremely high drawing force of 320 N
and a withholding force of 5,000 N with
a length of 535 mm and a diameter of
250mm. Such special technical features
are essential for the production of high
denier ranges such as 4 times dtex,
3,300 or dtex 13,300 total.
Oerlikon Barmag has recently developed highly-effective components and
aggregates such as extruders, mixers,
spinning systems godets and winders which all play an important role in
the production of top quality industrial
yarns. As a result of the combination of
these components and the expertise in
polymer and yarn manufacturing, these
machines meet both current demands
and those of the future. In this way,
manufacturers of industrial yarns can
produce these yarns on a reliable machine, at a high and consistent quality
level, with very good efficiency, at low
noise levels and with low energy consumptions.
The most recent technologies with
their multi-end layout as well as extremely high per-unit production capacities lower both the per-thread investment and the per-kg operating costs of
produced yarn. When comparing, for
example, dtex 6,600 with dtex 13,300
production capacities per position, a
100% higher production capacity can
be achieved with just an approx. 30%
higher investment per position.
Due to higher production capacity per
position, the operating costs decrease
by up to 20-30%, which ultimately provides a competitive edge in the market.
More than 300 Industrial Yarn positions
only sold in China since 2003 show that
Oerlikon Barmag technologies meet the
market demands and inspire our customers’ success.
[1] Wikipedia: www.wikipedia.de
[2] E. Schmalz, P. Böttcher, “Märkte und Einsatzgebiete von Geotextilien aus synthetischen
Fasern und Naturfasern”, Sächsisches Textilforschungs-institut e.V.