MAKE THE TOOLING CHANGEOVER TO
CONCEPT EXTRU-TECH LIMITED
EXTRUSION TOOLING TECHNOLOGY
CONCEPT EXTRU-TECH LIMITED
TEL: 44 (0)121 520 8252
QUALITY THE KEY TO SUCCESS
CONCEPT SHEATHING, STRIPING & SKINNING CROSSHEADS
CONCEPT
TORPEDO SPIDERS
CONCEPT EXTRU-TECH LTD.
UK’s NO.1 HI-TECH MULTI-LAYER DIE MANUFACTURERS.
CET 125 3-LAYER TUBE HEAD
 MULTI-PURPOSE TUBE DIE HEAD.
 FOR SINGLE LAYER TUBE WITH OR WITHOUT STRIPES.
 FOR TWIN LAYER TUBE WITH OR WITHOUT STRIPES.
 FOR THREE LAYER TUBE WITH OR WITHOUT STRIPES.
 CONVERSION TO CROSSHEAD FOR CONDUCTOR OR ROPE
OPTIONAL.
 DESIGNED TO MEET CUSTOMERS’ SPECIFIC REQUIREMENTS.
 DESIGNED WITH LATEST SPIRALCAD FLOW SIMULATION
SOFTWARE TO GIVE OPTIMUM OUTPUT AND MATCH MATERIAL
RHEOLOGY.
CONCEPT
SHEATHING
CROSSHEAD
40 MM
TO 75 MM
STATE OF THE ART
TECHNOLOGY
NO JOB TOO SMALL
CONCEPT
BREAKER
PLATES
TO SCALE - SEE
MOBILE PHONE
FLOWPATH FOR CREATIVE
150 SHEATHING & STRIPING
CROSSHEAD
Concept Extru-Tech
DESIGN AND MANUFACTURE
CROSSHEADS AND DIES TO
MATCH:
PRODUCTION OUTPUT
MATERIAL RHEOLOGY
CET USE COMPUPLAST  TECHNOLOGY
TO OPTIMISE THE FLOW OF MELT
THROUGH THE DIE
Side Fed Dies
Inflation Air
Exit Land


The center
mandrel is
supported below
the entry point of
the material.
Polymer enters
from the side and
flows around the
center mandrel.
Mandrel
Extension
Body
Inlet
Mandrel
Adapter
Balancing of flow is
required to ensure uniform
distribution
 Material
will prefer to take the
shortest path from the entrance
to the exit.
 This will result in more material
flowing along the inlet side.
Side Fed Die
Outlet
Inlet
Through Hole
Unwrapped Side Fed Die
Outlet
Chamber
Restriction
Inlet
Path Comparison
For uniform flow
P1
Q1
Inlet
P2
Q2
Side Fed Die
Potential Problems
Weld Line
Thick
Thin
Thickness Variation, Period = 2
SPIRAL MANDREL
TECHNOLOGY
FOR 3 LAYER
PETROLEUM PIPE
Spiral Mandrel Dies


Commonly used
for tubular
(blown) film
production since
1950’s.
In more recent
years applied to
pipe and blow
molding dies
Spiral Mandrel Die & Body
Spiral Mandrel Flow Field
DIE EXIT
ENTRY
PORT
DIE INLET
INFLATION AIR
MANDREL
BODY
Flow Path Comparison
P1 = P2
Qs3
Qs3
Qs2
Qs2
Qs1
Qs1
Qin
Fully 3-D Flow Field
Weld Line Orientation
Spider Die
Spiral Die
Design Evaluation
Flow Distribution
Good Design
Uniform Thickness
Poor Design
Periodic Thickness
Equal to # of Spirals
Design Evaluation
Flow
Variation
Circumferential Position
Slow Initial Leakage
Channel
Flow
Fast Initial Leakage
Channel Position
Spiral Mandrel Die
Thickness variation [%]
-8 -6 -4 -2 0 2 4 6
Comparison with experiment
Run 2
Run 1
0
60
120
180
Simulation
240
300
360
Position [°]
Potential Problem
Rapid reduction in channel flow will
result in the remainder of the
channel having too little material
flow and consequently a high
residence time
If sufficient material leaks out prior
to the first spiral overlap, then it is
quite likely that this will result in a
visual defect in the final product.
A type of Port Line
Design Evaluation
Additional Criteria
Final Distribution
 Velocity/Shear Rate/Shear Stress
 Pressure Drop
 Sensitivity to Material Changes
 Sensitivity to Process Conditions
 Sensitivity to Manufacturing
Tolerances

STACKED DIES
•Each layer is added
sequentially.
•Each distribution module
can have the same
surface area.
•All layers (except the
inner layer) can have the
same residence time.
CONCEPT 150 CROSSHEAD
CONCEPT 150 CROSSHEAD
GENERAL ARRANGEMENT
WALL SHEAR
STRESS FIELD
THE
PROCESS OF
SIMULATING
FLOW
THROUGH
THE DIE
SHOWING
THE SHEAR
STRESS
150 CROSSHEAD
WALL SHEAR RATE FIELD
THE PROCESS
OF
SIMULATING
FLOW
THROUGH
THE DIE
SHOWING
THE SHEAR
RATE
150 CROSSHEAD
PRESSURE FIELD
THE PROCESS
OF SIMULATING
FLOW
THROUGH THE
DIE SHOWING
THE PRESSURE
DROP
THROUGH THE
DIE
150 CROSSHEAD
AVERAGE RESIDENCE
TIME FIELD
THE PROCESS
OF
SIMULATING
FLOW
THROUGH THE
DIE SHOWING
THE MATERIAL
RESIDENCE
TIME
150 CROSSHEAD
BULK TEMPERATURE
FIELD
THE PROCESS
OF SIMULATING
FLOW
THROUGH THE
DIE SHOWING
THE
TEMPERATURE
VARIATIONS
150 CROSSHEAD
CONCEPT
GUIDE PINS
CET 420 CALIBRATOR
POLYMER FLOW DISTRIBUTOR
CET HAVE SOLUTIONS
TO YOUR PROBLEMS
PROUD OF A
HIGHLY SKILLED
WORKFORCE
CET EXTRUSION TOOLING
CET CRAFTMANSHIP
SPIRAL MANDREL INNER DIE
PROVIDING
YOU WITH
QUALITY
TOOLS TO
MANUFACTURE
YOUR QUALITY
PRODUCTS