Extrusion system
It is used to extrude PE adhesive and PE protective coating, which are twined to the external wall of the pipes. The polyethylene protective coating can protect the epoxy powder coating.
It can be divided into cladding type and twining type according to coating pattern and twining type can be divided into side type and upper type.
The cladding type
Two sets of extruder are placed on live platform which can drive die go up and down. There are two guide rails which can help adjust the distance between die and pipes. Two sets of dies can move up and down according to different needs. Pipes can go directly through the die and AD & PE can wrap on the pipes uniformly.This can not only help save material, but also prevent roller from wearing.
However, since the coating line is running in linear way, the homogeneity of the powder coating may be affected, so this device is only suitable for the pipes with diameters under 630.
Twining type (Side type)
In this type, die is side blew pipes and the adhesive and polyethylene press rollers are directly blew pipes. The AD extruder and PE extruder are placed vertically with production line. They can move back and forward (AD extruder can move laterally) to adjust the angle between coating layer and steel pipes.
Twining type (Upper type)
Two sets of extruder are placed on one side of production line. The extruder is vertical to production line. The extruders are placed on live platform and die and extruder can move up and down. Pressing roller and guide roller are separately placed on a live scaffold. This can help easily adjusting the extrusion and wrapping equipment according to different pipes and also adjusting the width of coating layer. It can not only ensure the uniformity of PE, but also save raw material.
Since the space under pipes is unlimited, pipe carrier can be installed under pipes. As a result, there is no need to use pipe connecting device. In the meanwhile, the cutting of rudder at the end of pipes can be achieved.
Co-extrusion
This type of extrusion develops on the basis of consumer's different needs. One set of extruder can be installed flexibly and wrap in many ways, in addition, the cost is low. Co-extrusion type is really suitable for coating pipes with different diameters. Consumer can choose one extruder or two according to different production requirement. It can greatly save production cost, but its price is a little bit high.
