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PO 450 CR Monolayer cross head up to 450 mm for thin PP layer |
CONEXTRU GmbH designs and built cross heads for any kind of coating application. This can be a pipe in pipe production, coating, and bundling of small pipes for optical fibres, coating multilayer structure to produce barrier layer for small pipes like floor heating or large pipes like water transportation pipes, or single layer coating as a protection layer for handling during installation. Cross dies is a preferred alternative process to produce the jacket pipe of pre-isolated pipes for the in line process. The diameter of such heads can be up to 1000 mm – theoretically also bigger. The system of distribution depend of Polymer output and layer thickness and preferred system is the helical or radial spiral distributor. For multilayer structure also a combination of both – if required by application.
There are some advantages for the coating process compared to a multilayer pipe productions and these are as following:
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Quick change from monolayer to multilayer
PO 3 160 – flow channel of a 3 layer head - Wide range of diameters with one head e.g. 32 – 315 or 63 to 500
- Wide range of dimeters with 1 die set, e.g. 4
- Highest flexibility in multilayer production
- Multiple coating and coextrusion possible with more than 1 cross head
- Thin and thick layers can be applied
- Adhesion adjustable by temperature –important in case of peeling the outer layer for electrofusion welding
- Very accurate diameter of basic pipe, important if the layers must be peeled off for electrofusion welding
- The inner pipe has calibrated surface
- Only with cross heads in line pipe in pipe extrusion
- Easy possibility to insert wire for detection
- Printing on outer surface of basic pipe possible
- Simply coating process by under pressure
- Under pressure by speed adjustment of blower, no vacuum needed
Following types of cross heads have been designed and delivered
Monolayer Cross heads Multilayer Cross heads:
PO 63 CR PO 2 160 CR-R Adh. / EVOH
PO 125 CR PO 2 160 CR PE / PP
PO 250 CR-R PO 4 160 CR PERT / Adh. / EVOH/Adh.
PO 40 CR PO 3 160 CR PP / PP+Baso4 / PP
PO 450 CR PO 4 180 CR PE / Adh. / EVOH / PE+Adh.
PO 500 CR PO 3 315 CR PP / PP+Baso4 / PP
PO 630 CR Projects :
PO 3 630 CR PE / Adhesive / EVOH
PO ... Polyolefins; Number of layers, CR- cross head type; R with radial distributor included
Application example
The last project is a cross head to cover 630 mm pipe with 2 mm PP single layer
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| During mounting at manufacturer. PO 630 CR |
Some technical datas:
Name: PO 630 CR cross head for pipe coating
Max. Throuput PE 100 300 kg/h
PP-R, PP-H 300 kg/h
Application: for single layer coating of steel pipes or plastic pipes
Coating method: vacuum sizing with vacuum pump, on backside of head is a short steel tube with rubber sealing, the vacuum pump is connected with a tube to back side of head to evacuate inner volume of head to bring the melt to the pipe which has to be coated.
Head range: 180 – 630 mm pipe
Die Design: Master die set 630; for coating 630/ 560/500, with one mandrel with a gap of 6 mm for 3 mm layer. On this die is mounted:
Die set 450; for coating 450/400/355, with one mandrel with a gap of 6 mm,
On this die set is mounted:
Die set 315; for coating 315/280/250, with one mandrel with a gap of 6 mm
On this die set is mounted:
Die set 225; for coating 225/200/180, with one mandrel with a gap of 6 mm
Die change: in horizontal position by crane – pusher screw for easy re- movement
Mandrel change: in horizontal position – with special tool to open trapeze thread
Flow Channel: helical spiral distributor with 20 channels
2nd layer: option by radial spiral plate
Heating: heat up time within 4 hours,
outside heater bands; Inner heater for body and bigger mandrels
Backside heater or minimum Isolation
