Page 50 - February-March-2017

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By: Dr. Lassad Nasri leading solution supplier in the area of plastic recycling
Senior Manager Technology and Product Management systems and technologies. Both companies joined their
Articles Filament (BCF) for carpet applications.
Trützschler Switzerland AG
efforts to develop a one-step system for pre-processing
and spinning polyester flakes into Bulk Continuous

The new system directly links EREMA’s VACUREMA®
technology with Trützschler Switzerland’s symTTex BCF
machinery (figure 2). The EREMA part consists of a
vacuum reactor, a directly linked single-screw extruder
Production of BCF yarn from

extruder and then forced through a large area filter of
value virtually reaches the IV value of the flakes (figure
recycled PET (R-PET) and a high-performance filter. Washed R-PET flakes are dried and decontaminated in the reactor, melted in the When measuring the yarn’s viscosity we see that its IV
3). This proves that the drying process is extremely
variable fineness. After that the high-quality melt is
transferred to the Trützschler spinning system. The
efficient - the vacuum before the extrusion process
removes moisture and volatile material very effectively.
well-known and established high quality spin packs,
A new technology from dual shell draw rolls, the HPc texturizing system and The combination of EREMA’s and Trützschler’s systems
fully driven winders form the filaments and wind them
allows for producing distinct BCF yarns with high
onto bobbins. An industrial line is already successfully
Trützschler Switzerland AG and running in Poland. efficiency, excellent process stability and low
transformation costs (table 1). Market requirements and
EREMA A one-step process for high-quality yarns expectations when using 100% R-PET flakes or
mixtures of flakes with virgin material are fulfilled.
EREMA’s patented system enables the feeding of clean Table-1
All of us use plastic bottles almost every day. the collection of the bottles and pressing them into flakes directly into the reactor without using neither
Especially life without bottled water is not conceivable bales. Afterwards, the bales are opened, sorted out crystalliser nor dryer. A major advantage is the energy The cooperation of Trützschler with EREMA for recycled
in developing and developed countries. Whereas and grinded. The flakes obtained are washed (cold savings because energy-intensive drying and polyester constitutes a major pillar in Trützschler’s
glass was the main material for bottles in the last and hot) and separated from the polyolefin, which crystallizing steps are omitted. product portfolio of solutions. It perfectly adds to the
century, producers and consumers more and more comes from caps and gaskets. After drying and metal already established systems for the production of PA6,
favoured PET – polyethylenterephthalate - since the separation, the flakes are practically ready to be filled PA6-6, virgin PET and PP BCF yarns. It is a step ahead
late 1980s. These “polyester” bottles come with the into silos or big bags. A new cycle begins. From bottles to BCF yarn toward market demand for more sustainable end
distinctive advantages of being light weight and products.
almost unbreakable. One of the main processes for recycled polyester is Spinning BCF yarn from PET and R-PET
spinning staple fibers, which can be used for spun
However, the success generates the new challenge of yarns, textile fillings or nonwoven materials for PET fibers offers numerous advantages in carpet
applications. Especially the high stain resistance should
coping with billions of discarded bottles each year. instance. These applications are well established with be mentioned, which is even higher than that of
When the bottle is empty we often throw it away, even fleece shirts and throws being prominent examples. chemically treated PA BCF. Moreover, PET can be spun
though some of us would keep it for a second life. In in undyed form, which is not the case for PP. Undyed
many regions of the world recycling is an option. In Besides, due to many factors, the collection and yarns can be twisted, heat set, dyed and tufted or the
Asia, for example, the probability that an empty bottle recycling rate of plastic bottles is growing worldwide. finished carpet can be printed.
will be recycled is more than 75%. However, Therefore it is time to explore new end uses of the
unfortunately there are also regions with recycling recycled PET like carpet application for example Compared to staple fiber production, using R-PET for
rates not exceeding 15%. (figure 1).
manufacturing continuous filaments is much more
challenging. In filament spinning the quality of the yarn
Recycling in Asia is widespread because especially is determined by the homogeneity of the raw material.
entrepreneurs in China early recognized PET bottles Recycled flakes are an instability factor, small deviations
as a valuable raw material. Using recycled polyester in quality can lead to an increased number of filament
flakes offers numerous advantages: the economical breaks or broken filaments. Further, the variance in the
aspect (flakes are cheaper than virgin chips) and the flakes quality could affect the yarn’s colour pick-up so
sustainability/good image aspect (green label) are to the finished carpet shows streaks.
be mentioned among them.
The EREMA-Trützschler system
Recycling PET bottles This challenge is the reason that Trützschler and
A long and complex process chain is needed to turn a EREMA started to collaborate. EREMA Engineering Fig 2. Illustration of the EREMA-Trützschler system
used bottle into usable raw material. It all starts with
Fig 1. From bottles to BCF yarn Recycling Maschinen und Anlagen Ges.m.b.H. is a