EoW January 2010

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EuroWire – January 2010 72
Extruding – machinery & equipment
Cross-head for XLPE and thermoplastics
HFFR compounds
The extrusion head is among the components that ensure and maximize the
functionality and potential of an extrusion line. The quality of an extruded material is
directly and exponentially proportional to the proper functioning and design of the
extrusion head.
The size of the axial and distribution channels is important to ensure the regularity
of the flow and avoid high kinetic differences in the material which cause localised
overheating of the material, and also to avoid degradation or thermo-stress of the
material, ensuring the right conditions for both melt and mixing.
Equally important is the assembly, sizing and centring of the tools to be used. For this
reason an extrusion head has been developed that allows balancing of the piezo-kinetic
effect for sensitive materials (HFFR, LSOH, XLPE cross-linkable by monosil, visico and
sioplas processes).
Pressure and temperature transducers detect the condition of the processed material
to avoid overpressure and heat strokes, as in the case of halogen-free materials. To
optimise the system, a pair of special semi-compression tools were developed.
During production it is possible to vary the pressure and temperature of the molten
material by adjusting the axial position of the tip or die. As a result of that procedure,
it is possible to improve the adhesion of polymer on the cable, so avoiding defects
such as surface vibrations, micro-crack, localised overheating and shark-skin effects.
Eurotek Srl – Italy
Fax: +39 0872 711978
Email:
Website:
NewTPEs
A new series of Elexar® thermoplastic elastomer
(TPE) compounds for wire and cable, from the
Thermoplastic Elastomer Division of Teknor
Apex Company, provides a combination of
RoHS compliance, UL-V0 flame retardance,
and excellent performance over a wide
range of end use conditions. The Elexar
high-performance FR series includes six grades,
with Shore A hardness ranging from 58 to 85,
upper use temperature from 105ºC to 125ºC,
low-temperature flexibility down to -50°C,
excellent UV resistance, and good oil resistance.
For applications where appearance is critical,
the compounds provide excellent colourability
and non-blooming surfaces, according to Keith
Saunders, market manager.
“Elexar HPFR compounds embody a hard-
to-find combination of outstanding end-use
performance and compliance with the
stringent standards required in the global
marketplace,” said Dr Saunders. “Conventional
flame retardant TPEs not only fail to comply
with the RoHS directives but are more limited
in terms of flame test ratings and service
temperatures. In addition, their flame retardant
formulations often present the problem of
blooming or surface staining.”
Teknor Apex suggests evaluating Elexar High-Performance FR compounds for use in insulation and jacketing for automation and
control cables, fibre optic cables, low-voltage power cables, appliance wire, and flexible cord. The new Elexar compounds meet
standards specified under UL 1061 and unlike conventional TPEs, pass the UL VW-1 vertical flame test for cable jacketing.
Teknor Apex Company – USA Fax: +1 401 728 5680 Email: Website:
Comprehensive
extrusion range
Threesixty Extrusion Technology designs,
manufactures and installs continuous
rotary extrusion equipment, tailored to
meet specific production requirements
from solid aluminium conductors through
to aluminium clad steel wire (ACS wire),
powder processing and large copper
busbar.
There are five standard continuous
extrusion machines in the Threesixty
range, to cover most product sizes and
applications:
The RX-320 for simple profiles in •
copper or aluminium up to 60mm
The higher throughput capacity •
RX-425 for products up to 120mm
The RX-530 for up to 200mm diameter •
The entry level TX-320 for sheathed •
products up to 20mm
The state-of-the-art TTX-320 with •
Threesixty’s patented extrusion shoe
positioning technology
Threesixty Extrusion Technology – UK
Fax: +44 1202 862446
Email:
Website:
Elexar HPFR used for a typical cable ▲ ▲