Back to results
US 2006/0231973 A1Published application
Spiral-webbed mandrel
AssigneeAmerican Maplan Corporation
InventorsHeinrich Dohmann, Reinhard Witt
Life of this patent
Estimating the term…
Abstract
An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar and an outer collar, and webs radially joining the inner collar and outer collar. The webs can be arranged twisted and/or offset in radial direction.
Claims8
A method for extrusion of hollow bodies, comprising:
- injecting a melt into a webbed mandrel;
- and
- in the webbed mandrel, dividing the melt around twisted webs which are offset in a radial direction from an inner collar and an outer collar of the webbed mandrel.
Dependencies are inferred from the claim text.