System and method for applying moldable material to a pipe by injecting moldable material from a movable support
A molding system for applying moldable material to a pipe. An elongate mold has at least one elongate mold member movable relative another elongate mold member between open and closed positions. The mold includes a pipe support that extends generally radially into a mold cavity along a support axis. An inner end of the support is configured to support the pipe in a molding position in which an annular portion of the mold cavity extends circumferentially around the pipe. After moldable material in the annular portion of the mold cavity can support the pipe, the support is withdrawn from the mold cavity by moving outwardly along the support axis. An injector selectively dispenses additional moldable material into a space formed by the support in the existing moldable material.
1. A method of applying a moldable material to a pipe comprising;
supporting the pipe in a molding position within a mold cavity defined by a mold using a support extending generally radially into the mold cavity along a support axis transverse to a longitudinal axis of the mold;
at least partially filling an annular portion of the mold cavity extending circumferentially around the supported pipe with a first portion of the moldable material;
at least partially curing the first portion of the moldable material in the mold cavity; and
withdrawing the support from the mold cavity by moving the support generally radially outwardly along the support axis after the first portion of the moldable material in the mold cavity supports the pipe in the molding position; and
while performing the step of withdrawing the support from the mold cavity, filling a space in the mold cavity that is vacated by the support with a second portion of the moldable material, wherein the second portion of the moldable material is not present in the mold cavity until the support begins withdrawing from the mold cavity;
wherein the step of withdrawing the support from the mold cavity is performed after the step of at least partially curing the moldable material.
2. The method as set forth in claim 1 wherein the step of filling the space comprises injecting the second portion of the moldable material from the support into the mold cavity while withdrawing the support from the mold cavity.
3. The method as set forth in claim 1 wherein the step of at least partially curing the first portion of the moldable material in the mold cavity comprises defining with the support the space in the at least partially cured first portion of the moldable material.
4. The method as set forth in claim 3 further comprising injecting the second portion of the moldable material into the space from an end of the support as the support is withdrawn from the mold cavity.
5. The method as set forth in claim 4 wherein said injecting the second portion of the material into the space causes said withdrawing of the support from the mold cavity.
6. The method as set forth in claim 1 , wherein the pipe has a length of greater than 45 feet.
7. The method as set forth in claim 3 , wherein the step of at least partially curing the first portion of the moldable material comprises curing the first portion of the moldable material sufficiently to have a self-retaining shape such that a shape of the space is retained as the support is withdrawn.
8. The method as set forth in claim 3 , wherein the space in the cured mold material is not filled by flowing of the partially cured first portion of the moldable material as the support is withdrawn.