US4616055A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous irrigation pipe and method
Assignee: Aquapore Moisture Systems Inc
•
Filing: 1985-05-13
•
Granted: 1986-10-07
•
Expires: 2005-05-13
Abstract
Abstract A mixture of virgin crumb rubber sized to between 30 mesh and 100 mesh containing less than 5%+100 fines and thermoplastic binder, such as carbon black filled polyethylene containing a coating promoter, such as a citrate salt and lubricant, such as a calcium stearate, is mixed in a vented Banburg mixer heated to at least 350 DEG F. to remove volatiles through vent before extrusion. The mixture is formed into sheet in the nip of a two roll assembly and cooled in air before diced into pellets by a dicer. The pellets are formed into porous pipe by extrusion in a pipe extruder having the feeding, transition and metering zones separately heated to temperatures from 320 DEG F. to 400 DEG F. (T1, T2, T3). The die has a separate jacket receiving heat exchange fluid for heating the die to a temperature from 290 DEG F. to 380 DEG F. to form a porous pipe having more uniformly spaced and sized pores and a smoother inner wall surface. The linearity factor, tensile strength and elongation are also improved.
Inventors
- 👤 James W. Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:27
CPC Classifications
B; B29; B29B; B29B17/00; B29B17/04; A; A01; A01G; A01G25/00; A01G25/06; B29B17/0026; B29B17/0042; B29B9/00; B29B9/02; B29B9/06; B29B9/065; B29B9/12; B29B9/16; B29D; B29D23/00; B29D23/001; B29C; B29C2793/00; B29C2793/009; B29C48/00; B29C48/001; B29C48/0012; B29C48/03; B29C48/09; B29C48/10; B29K; B29K2021/00; B29K2105/00; B29K2105/04; B29K2105/26; B29L; B29L2023/00; B29L2023/22; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62; Y10; Y10S; Y10S138/00; Y10S138/07
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
60 words
A porous pipe comprising a hollow pipe having a pipe wall containing uniformly spaced pores, said pipe being formed of uniformly sized, vulcanized elastomer particles differing by no more than 5% from an average size dispersed in a thermoplastic resin, at least 90% of the particles exposed on the inner wall of the pipe being coated with said binder resin.
Claim 2
Dependent Claim
60 words
A porous pipe comprising a hollow pipe having a pipe wall containing uniformly spaced pores, said pipe being formed of uniformly sized, vulcanized elastomer particles differing by no more than 5% from an average size dispersed in a thermoplastic resin, at least 90% of the particles exposed on the inner wall of the pipe being coated with said binder resin.
Claim 3
Dependent Claim
13 words
A pipe according to claim 1 in which the elastomer is vulcanized rubber.
Claim 4
Dependent Claim
16 words
A pipe according to claim 2 in which the rubber is a carbon-filled, virgin scrap rubber.
Claim 5
Dependent Claim
18 words
A pipe according to claim 1 in which the particles are sized to between -30 and 100 mesh.
Claim 6
Dependent Claim
13 words
A pipe according to claim 1 containing no more than 5%+100 mesh fines.
Claim 7
Dependent Claim
14 words
A pipe according to claim 1 in which the binder is a polyethylene resin.
Claim 8
Dependent Claim
17 words
A pipe according to claim 6 in which the polyethylene resin contains less than 1% coating promoters.
Claim 9
Dependent Claim
24 words
A pipe according to claim 7 in which the coating promoters comprise at least one material selected from a citrate salt and carbon black.
Claim 10
Dependent Claim
35 words
A pipe according to claim 8 in which the citrate salt is present in an amount from 0.001 to 0.1 phr and the carbon black is present in an amount from 0.1 to 1.0 phr.
Claim 11
Dependent Claim
22 words
A pipe according to claim 8 having a linearity function Cv from 0.1 to 0.25 and a fluid friction coefficient above 100.
Claim 12
Dependent Claim
18 words
A pipe according to claim 10 having a tensile strength above 800 and an elongation % below 1.00.
Claim 13
Independent Claim
59 words
A method of forming particles for use in an extrusion process comprising the steps of: mixing a mixture of rubber particles and binder resin while heating it to at least the temperature to be encountered during the extrusion process; removing volatiles from the mixture during the mixing step; forming the mixture into sheet; and comminuting the sheet into particles.
Claim 14
Independent Claim
59 words
A method of forming particles for use in an extrusion process comprising the steps of: mixing a mixture of rubber particles and binder resin while heating it to at least the temperature to be encountered during the extrusion process; removing volatiles from the mixture during the mixing step; forming the mixture into sheet; and comminuting the sheet into particles.
Claim 15
Dependent Claim
27 words
A method according to claim 12 in which the rubber particles are vulcanized, carbon filled, rubber in which the size does not vary by more than ±10%.
Claim 16
Dependent Claim
14 words
A method according to claim 13 in which the binder resin is a polyolefin.
Claim 17
Dependent Claim
12 words
A method according to claim 14 in which the polyolefin is polyethylene.
Claim 18
Dependent Claim
18 words
A method according to claim 15 in which the polyethylene contains less than 5 phr of carbon black.
Claim 19
Dependent Claim
20 words
A method according to claim 16 in which the polyethylene also contains less than 0.5 phr of a citrate salt.
Claim 20
Dependent Claim
14 words
A method according to claim 13 in which the sheet is commuted by dicing.
Claim 21
Dependent Claim
16 words
A method according to claim 18 further including the step of cooling the sheet before dicing.
Claim 22
Dependent Claim
30 words
A porous pipe according to claim 5 in which at least 95% of the particles on the surface of the inner wall of the pipe are coated with binder resin.
References Cited (Backward Citations)
US4003408A
Cited
US4013102A
Cited
US4094466A
Cited
US4162863A
Cited
US4168799A
Cited
US4238260A
Cited
US4434250A
Cited
US4517316A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |