www.microdia.ch Your expert in extrusion SWISS MADE °microdia °microdia N EWSLETTER N O 37 Compression tooling for small cross heads . The most common type of tooling. Pros: Insulation is applied to the conductor or core under compression assuring maximum adherence between these two elements. Outer surface of insulation is perfectly round, unevenness of the strand are filled during the transit through the compression zone. Cons: Wire tension builds up in the compression zone, can be an issue when running at high speed, for instance in tandem telephone line. Stranded cable insulation adherence can be high due to the penetration of compound between the wires. Tape (aluminium, paper, etc) wrapped around cable can be damaged in the compression zone.
Compression tooling created by Maillefer more that 40 years ago to extrude PVC & PE became a world standard. Tips and dies are exclusively manufactured in Microdia's facilities in Switzerland
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www.microdia.ch Your expert in extrusion
SWISS MADE
°microdia
°microdia
N EWSLETTER N O 37
Compression tooling for small cross heads .
The most common type of tooling.
Pros:
Insulation is applied to the conductor or core under compression assuring maximum adherence between
these two elements.
Outer surface of insulation is perfectly round, unevenness of the strand are filled during the transit through
the compression zone.
Cons:
Wire tension builds up in the compression zone, can be an issue when running at high speed, for instance in tandem telephone line.
Stranded cable insulation adherence can be high due to the penetration of compound between the wires.
Tape (aluminium, paper, etc) wrapped around cable can be damaged in the compression zone.
www.microdia.ch Your expert in extrusion
SWISS MADE
°microdia
°microdia
Newsletter No 37 Pa ge 2
Wire guides or tips.
Solid hardened steel body. Economical yet precise. Ideal for insulated wire second layer. Widely used on low speed lines.
Line speed 300—400 m/min: hardened steel.
Line speed 300—1200 m/min: tungsten carbide insert.
Line speed 1200—2400 m/min: diamond insert.
Solid hardened steel body with tungsten carbide insert.
The best option quality/price for medium speed lines.
Very good core guiding thanks to the insert length.
Good life span.
Solid hardened steel body with se-lected synthered diamond insert.
Applications, Lan, telephone, auto-motive, building wire lines.
Life span: more than120’000 km. Natural diamond on request for
small size wires.
www.microdia.ch Your expert in extrusion
SWISS MADE
°microdia
°microdia
Newsletter No 37 Pa ge 3
Dies: hardenend steel or tungsten carbide
Multi-purpose die designed for telephone lines, Lan, building
wire, signal wire, automotive
wire etc.
A long compression zone guar-
antees good adherence and
perfect insulation concentricity.
Standard die
Short die
Long die
Similar to standard die but with 3 mm shorter compression
zone.
Created to solve the problem of
excessive wire tension build up
in the head when running
small size wire at high speed.
Can be helpful to reduce the
extruder’s pressure when ex-
truding viscous compounds.
Similar to standard die but with
5 mm longer compression zone.
Developed to solve the problem
of periodical eccentricity of PP
isolation due to its helicoidal
molecular structure.
The long compression zone may increase extruder pressure
and limit the line speed.
www.microdia.ch Your expert in extrusion
SWISS MADE
°microdia
°microdia
Newsletter No 37 Pa ge 4
Configurations
Single angle tip; two angles die.
Exponential compound acceleration between tip & die. Fairly long compression zone. High pressure in the compression zone. Perfect for solid core insulation. Good concentricity. Risk of strand dislocation if lay length is long or strand loose.
Fig.1
Fig.2.
Compression classic (fig.1).
Compression 3 angles (fig.2).
Two angles tip; three angles die.
Initially developed to extrude foam PP with constant pressure and linear flow.
Two steps exponential compound acceleration between tip & die., Reduced material stress during acceleration. Low pressure in the shorter compression zone. Recommended for compound difficult to extrude due to their molecular structure.