Maintenance tips – the key to energy
savings
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Over a period of
ten years, the costs of energy (electricity, steam, gas)
accounts for more than 60% of the initial investment of a
finishing system. Skilled operation and regular maintenance
of the Monforts system can subsequently reduce costs. This
article is intended therefore to highlight simple tasks and
tips to assist the machine operator to save energy whilst
maintaining the high quality of fabric treatment. |
It is important to know and understand the maintenance plan
for the installation. Only a system which is maintained
regularly can provide full output with most economic input of
energy.
The system’s lint filters should be inspected at least once
every shift to ensure that they are clean and they must be
cleaned with a brush or vacuumed if necessary.
The heat recovery modules also require cleaning at the
prescribed intervals. Soiled screens and heat exchangers reduce
the output of the system substantially and increase the energy
consumption.
Systems without Qualitex: the setting of the contact pressure
of the padder should be within the working area of the diagram
at the operator console to ensure that the squeeze effect is
uniform over the full width.
The more moisture that is removed and, the better it is
removed, the less energy is required for drying.
Drying temperature range from 105º to 150ºC (depending on the
fabric). Material, finishing agents and methods determine the
drying temperature. The recommendations of the dyestuff and/or
chemicals producers should be observed. High drying
temperatures not only consume too much energy, they often also
damage the fabrics to be finished.
Pay attention to the optimum drying and heat-setting
temperature.
An important aspect for good drying is to measure and control
the exhaust moisture which is the moisture contained in the
exhaust air of the dryer. Depending on the fabric and the
initial moisture, the optimum values are 10-20% by volume. If
the exhaust contains less moisture, too much fresh air is heated
and energy wasted. If the exhaust contains too much moisture,
drying is poor; it takes more time and energy is wasted. When
drying is the only purpose, it is important to monitor the
residual moisture - being the moisture contained in the fabric
when it leaves the system. The optimum residual moisture is
measured with a humidity meter at the outlet of the dryer then
controlled as needed.
Some examples of optimum residual moisture:
- Co 6-8%
- CV 8-10%
- Wo 10-12%
- PES 1-2%
- PES/Co 2-4%
If the fabric is very dry, too much energy is wasted and
drying is too expensive. At the same time, production is
unnecessarily slowed down. Too little residual moisture also
causes loss of quality.
Optimising the dwell time. Depending on the fibre, the
heatsetting of textiles requires a certain dwell time which must
be observed to obtain the required fabric characteristics.
Usual dwell times
PES = 10 seconds at 185-200ºC (depending on fibre supplier)
Elasthane = 30-45 seconds at 185-195ºC (depending on fibre
supplier)
All stenter frame chambers should have the required
temperature for heatsetting.
 To
obtain the optimum production speed at the required dwell time,
automatic control (Monformatic) is a necessity. This will
ensure the optimum production speed with minimum energy
consumption.
Since heat setting is a process without exhaust moisture, the
exhaust fan motor cannot be controlled by the exhaust air
moisture meter. The setting should be done manually to maintain
a slight vacuum in the stenter.
Normally this exists at 50-60% exhaust capacity. If the
product tends to evaporate and the stenter emits smoke at the
inlet and outlet openings, the speed of the exhaust fan motor
should be increased until no smoke is emitted.
The lower the exhaust volume, the
less energy is consumed
If Thermat is fitted it should be set to 70-80ºC. This
ensures automatic control of the exhaust fan.
- Setting time: Is the heating time + dwell time
- Heating time: Is the time to obtain the required dwell
temperature
- Dwell time: Is the
time the fabric remains in the machine after the heating time.
The speed of the air circulation fan motors should be
adjusted as needed. Higher speeds for heating, lower speed
during dwell time.
Setting the air circulation fans (with stenters).
 The
Montex stenter is equipped with the TwinAir system where the
flow rate for bottom and top air can be set separately. Set the
air circulation fans to ensure that the fabric ‘floats’ in the
dryer without making contact. Some common fan settings for
maximum process speeds are illustrated.
Do not heat the system longer than is needed. Do not hold
the system at temperature without fabric longer than necessary.
Both waste energy and contaminate the environment.
Refurbishment
Monforts offer a variety of modification and extension kits
for older systems. If a heat recovery unit is service-fitted up
to 30% of the energy needed for heating can be saved.
If the air circulation fans are fitted with modern frequency
converters, the consumption of electricity can be drastically
reduced. And that with the shortest pay back period you can
imagine.
The Monforts soft-coating® method reduces the starting
moisture. This saves energy otherwise spent on drying or the
production speed can be increased.
Online tele service
Any machine downtime costs money. Therefore, modern Monforts
systems are serially shipped with online tele service. This not
only reduces the start-up time during the commissioning phase,
it also ensures direct online assistance by the supplier if a
problem occurs. This ensures the shortest downtime, software
updates and reprogramming and modernisation of machine controls.
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Light at the end
of the tunnel: Fresh start for Trevira
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From the fibre
and flat filament yarn through to dyed textured yarns,
Trevira is the only supplier in the world that offers
the complete range of textile polyester products from
the one source. Fields of application are home and
household textiles, apparel, automotive interiors,
hygiene textiles and technical applications.Trevira is
the first call for specialties such as fibres and yarns
for flame retardant or permanently antimicrobial
textiles. |
The last twelve
months have been testing ones for the whole textile industry
and not least for Trevira. From the financial crisis,
insolvency and restructuring a new and compact company is
emerging, which will concentrate on its core business in
profitable polyester specialties.
The rapid
conclusion of the sales negotiations only two months after
filing for administration marks the first step towards a
successful new start.
As from the 1st
October 2009 the new owners of Trevira and the Frankfurt
entrepreneurs Stefan Messer and Karl-Gerhard Seifert.
They have
demonstrated a long-term business interest in the polyester
manufacturer.
“On the basis of
our own entrepreneurial experiences we intend to set the
traditional brand of Trevira back on a successful course in
the apparel, home textiles and automotive industries as well
as in the hygiene sector, and secure maintenance of jobs in
the long term. Following the many changes of ownership over
the last decade, we are convinced that the restructured
Trevira now possesses all the prequisites to become a stable
and sustainable business“.
The new company
will comprise the three production sites Bobingen (Germany),
Guben (Germany) and Zielona Góra (Poland), together with the
sales location in Hattersheim near Frankfurt, involving a
total of some 1450 employees.
MoOD 2009 – show
and marketing activities
The Trevira CS
brand will continue to play the leading role in the new
company as well.
The product range
is to be maintained, guaranteeing customers provision of
flame retardant Trevira fibres and yarns by Trevira and its
partners for the future as well. Sales and marketing
activities will carry on as usual.
With a stand at
MoOD, Trevira is flying the flag even in this difficult year
and is maintaining the Trevira CS Award for the most
innovative customer collection of flame retardant Trevira CS
fabrics. On the Trevira stand 27 Trevira CS suppliers are
showing a total of 33 articles, presenting a colour spectrum
ranging from hard white, grey and green to yellow green.
The sustainability
of Trevira CS fabrics is a central theme of the stand
message. Trevira’s product developer Anja Greger is a member
of the international panel for the selection of the “Blue
drop“ products. This is a new initiative of MoOD, to award a
prize to the best products submitted for the MoOD sample
bank.
The converter
catalogue “Fabrics Make a Place“ was welcomed at its first
appearance in 2007 and this year will be available in the
second edition.
At the end of
August it was circulated worldwide to around 12, 000
furnishers and interior designers, who have the opportunity
to learn about the latest developments by 46 fabric
suppliers.
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