METHOD AND APPARATUS FOR COATING A PIPE

摘要

A method for coating a pipe involves applying a coating material of cellular structured extruded thermoplastic material to the pipe and enclosing it on the outside by an outer covering layer of compact plastic. In an extrusion head, the annular opening for supplying coating material can be adjusted to a desired temperature by a region having coolant channels separated from the annular opening by an annular heat exchange surface. Before being applied to the pipe, the flowable coating material is guided along the heat exchange surface and cooled to a temperature just above the solidification temperature thereof. After the coating material leaves the annular opening, the coating material expands in a controlled manner, widening the outer covering layer depending on the adjusted temperature of the coating material, until the coating material begins to solidify. The outer covering layer surface condition can correspond to or be different from the pipe.

主权项

1. A method for coating a pipe, the method comprising:
guiding a coating material, which is flowable and comprises an extruded thermoplastic material having a cellular structure, over a heat exchange surface of an extrusion head; cooling the coating material to a temperature not more than 30K above a solidification temperature of the coating material; applying the coating material to the pipe; and enclosing the coating material on its outside by an outer covering layer comprising a compact plastic.