Porous irrigation pipe prepared from particulate elastomer and thermoplastic binder containing controlled moisture content
US4517316A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1984 |
| Grant date | May 14, 1985 |
| Priority date | — |
| Expiry date | Jan 24, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S138/07
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A mixture of crumb rubber, binder, such as polyethylene, and slip contact agent, such as talc, and lubricant, such as a metal stearate, is formed in a blender (10), is shaped into pellets (32) by extruding a strand of the mixture (26) into water (28) and breaking the strand into pellets. The pellets (32) are adjusted to a preselected water content in drier (46) before storage in closed bags (50), stored and reinforced in a container (54). The controlled water content pellets (32) are formed into porous pipe (88) by extrusion in pipe extruder (62) having the feeding, transition and metering zones separately heated to temperatures from 320.degree. F. to 400.degree. F. (T.sub.1, T.sub.2, T.sub.3). The die has a separate jacket (90) receiving heat exchange fluid for heating the die (68) to a temperature from 290.degree. F. to 380.degree. F. to form a porous pipe (88) having more uniform porosity. Porosity is controlled by selecting water content of the pellets and controlling die temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.