Dual Spiral Systems has developed a PET tubing/pipe die for thick walled tubing extrusion. The 6" die body can be fitted with supplementary lip sets in order to produce pipes with outer diameters ranging from 1" to 15" and having wall thicknesses up to 2".
The die was optimized through in house computer simulation and tested extensively in the field. In order to cool the thick mass of plastic that makes up the tube wall, DSS incorporated a proprietary built in liquid cooling manifold that removes heat from both the inside and outside of the PET tube as it's being extruded from the die. The cooling section is thermally isolated from the heated portion of the die.
The glass-like inner and outer surfaces of the tube were achieved by using Dual Spiral Systems' K05 low friction coating, which also has applications in melt fracture elimination in blown film.
This latest tubing die incorporates DSS' spiral technology which has been used extensively in their blown film dies for many years. The result was very uniform thickness distributions and measured pipe wall thickness variation of less than 4% (3 sigma). Dual Spiral's flow channel design also ensures that the product is produced consistently with no machine oriented die or weld lines.
Dual Spiral Systems also makes tubing dies for various different materials and wall thicknesses.