Extrusion International 4-2026

37 Extrusion International 4/2026 Therefore, it is not necessary to incorporate any further compression sections. The ow channel subsequent to the torpedo should be streamlined with continuous degreasing until the nal gap is reached. The combina - tion of large volume and high compression, along with the small radius of the streamlined-shaped spider, results in a smooth inner surface without visible spider lines. The new series has also been redesigned in terms of throughput and volume. For all heads, the maximum throughput is achieved at a dwell time of 5minutes, while the minimum throughput is achieved at a dwell time of 15 minutes. This range of dwell times ensures smooth inner surfaces at high throughput rates while simultane- ously allowing for themaximumpossible thermal load on the PVC-formulation without causing thermal damage. The heads are made of chromium-molybdenum steel with a chromed surface, with the exception of the tor- pedo, which is made of stainless steel. Should there be a requirement for this, the complete heads are also avail- able in stainless steel. Ceramic heaters provide the necessary heating, both inside and out, especially for the torpedo tip, range adapters and mandrels, which are heated with special cylindrical inner heaters for optimal heat distribution. An isolation for the head is available as an option. Double strand extrusion Double strand extrusion is also a popular method when high-capacity extruders are available. Conextru offers two product lines: the PV-2 110 and the high-per- formance variant, the PV-2-160 HP, which is a modi ed version of the PV 160 designed for 1,000 kg/h per strand in total throughput of 2 metric tons per hour. The centre distance is determined according to cus- tomer requirements. If required, Conextru also offers vacuum cooling baths for double strand extrusion with PLC control for water temperature and vacuum level. Multilayer versions of PVC heads For two or three layers, including a foamed or high- ly lled middle layer, or for cross heads for coating, CONEXTRU offers ve different head sizes: PV 3 110, PV 3 160, PV 3 250, PV 3 400 and PV 3 630. The core of the heads is based on a coat hanger die for all three lay- Cross section Range adapter 280 – 400 Die sets PV 400 Die sets PV 250 Range adapter 110 – 250 Range adapter system