Variable porosity irrigation pipe
US4615642A · kind A · utility
25Cited by
7References
17Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1984 |
| Grant date | Oct 7, 1986 |
| Priority date | — |
| Expiry date | Oct 1, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Porous pipe having a porosity which varies continuously and controllably with length is produced by extruding a mixture of particles of prevulcanized elastomer such as reclaimed crumb rubber and a thermoplastic binder such as polyethylene with all parameters controlled except for die temperature of pull-off rate. By gradually varying temperature or pull-off rate during extrusion, the porosity of the pipe gradually changes. The leak rate can be controlled in a manner to produce a length of porous pipe in which the leak rate is constant as the pressure drops over the length of the pipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.