Method for manufacturing formwork pipe for pillar formworks for concrete building using spiral winding machine, involves introducing ripcord between layer of sheet material in mandrel and adjacent layer of sheet material during winding

摘要

The method involves forming a tubular blank with formwork pipe wall (2) that is provided with several layers of sheet material (4a,4b) that are wound in spiral shape and are overlapped with adjacent layers of sheet material using a mandrel (3). A ripcord (11) is introduced between the layer of sheet material in the mandrel and adjacent layer of the sheet material during winding. A handle is provided between the end of formwork pipe and end of ripcord. The formwork pipe end is received between the formwork pipe wall and end of ripcord. An independent claim is included for a formwork pipe.