Heat-insulating tubing
AssigneeKabel-und Metallwerke Gutehoffnungshuette AG
InventorsGerhard Ziemek, Ingo H. Pahl
Life of this patent
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Abstract
A tube is thermally insulated by helically wrapping a water-repelling spacer around the tube; longitudinally folding a paper ribbon carrying a separating medium around and onto the helical spacer; injecting a foaming material into the tube as it is being formed, and permitting the material to foam inside the folded ribbon; and further permitting the foam to cure and set. Subsequently, the ribbon is peeled off the foam and, preferably, a metal or metalized foil is wrapped around the exposed foam, which is followed by the extrusion of a thermoplastic, synthetic envelope onto the foam.
Claims11
A method of thermally insulating a tube, comprising the steps of:
- helically wrapping a spacer around the tube;
- longitudinally folding a ribbon carrying a separating medium around and onto the helical spacer;
- closing the ribbon along its edges to establish a closed tubular mold;
- injecting a foaming material into the tube as it is being formed prior to closing, and permitting the material to foam inside the folded ribbon and tubular mold, and further permitting the foam to cure and set;
- cutting and peeling the ribbon off the foam;
- and
- extruding a thermoplastic, synthetic envelope onto the foam.
Dependencies are inferred from the claim text.