TPT May 2015

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Technology News
May 2015 27
Contamination detection
in plastic pellets
THE purity of advanced materials, as
they are used in medical technology, film
extrusion, aerospace and automotive
industry as well as the production of
extra-high voltage cables, is a decisive
characteristic for the quality of the final
products. The production or use of
entirely clean materials is essential.
With the Purity Scanner, Sikora
provides a user-orientated system for
100 per cent online inspection and
automatic sorting of plastic pellets
before they get into the next production
process.
The Purity Scanner combines X-ray
inspection technology with a dual-axis
optical inspection system. This allows
the detection of metallic and organic
impurities as small as 50µm inside the
pellet and on its surface. Due to the
specially developed X-ray technology,
the Purity Scanner inspects even
coloured pellets for impurities, and sorts
them out automatically.
The Purity Scanner also
features a unique system
for transporting the pellets
within the device. The
feeding of the pellets is
carried out via a stainless
steel vibration feeder. The
material does not come
into contact with dust or
other contaminants from
the ambient air as the
transport system is sealed
and pressurised. This combination
ensures that the system sorts out the
contaminants without introducing new
ones.
The transport system is integrated
into an encapsulated housing and
slightly over pressurised, in order to
prevent contamination from entering
the system.
In the event that cleaning of the
system is required, the system can be
quickly and easily opened. The cleaning
concept was developed for customers
who run different materials or colours,
and want to clean the system when
changing the material.
In addition to cleaning, it is possible
to exchange the complete transport
system with a cleaned, sealed system.
Sikora AG – Germany
Fax: +49 421 48900 90
Email:
Website:
The Purity Scanner combines X-ray and optical techniques
Bonding of CRA lined pipes
CRA lined pipes or CRA clad pipes are
corrosion-resistant pipes consisting
of a corrosion-resistant inner pipe
and a carbon steel outer pipe that
can withstand internal and external
pressure.
Potential applications for pipes with
CRA material are subsea pipelines
for sour gas and oil, water reinjection
systems, saltwater pipelines, and
process pipes in the chemical industry.
CRA lined pipes are mainly used as
flow-lines, riser pipelines, interfield
pipelines and water injection pipelines.
There are two methods of bonding
the CRA material to carbon steel:
metallurgical bond (CRA clad pipes) and
mechanical bond (CRA lined pipes).
The metallurgical bond between two
different metals (bonding of plates) is
achieved by hot rolling, co-extrusion,
weld overlay or explosive bonding. A
disadvantage is the limited number of
suppliers due to the demanding and
complex manufacturing process of
metallurgical bonding the plates, which
creates high costs. Mechanical bonding
between the backing steel pipe and
the CRA pipe by use of spring back
variation can be performed by means
of hydroforming or by a full length pipe
expander.
There is growing demand for CRA
lined pipe due to the fact that corrosive
conditions are expected to increase
as produced fluids contain higher
water cuts and greater concentrations
of H2S and CO2. In addition, these
increasingly corrosive products need to
be transported over longer distances,
with higher pressures, and in an
environmentally friendly way.
Fontijne Grotnes has found a solution
to bond the backing steel pipe and the
CRA pipe with the company’s full length
pipe expander, for which a patent is
pending. The company has more than
40 years’ experience in designing and
manufacturing full length pipe expanders
for the LSAW pipe industry.
A special expander head design is
used to ensure uniform mechanical
bonding of the inner and outer pipe
over the complete contact area. The
full length pipe expander is equipped
with a linear transducer that accurately
measures the position of the dies.
Fontijne Grotnes Group – Netherlands
Email:
Website:
Full length pipe expander for CRA lined pipes