Recycled rubber railroad crossties

• US 6,766,963 B2
• Filed: 11/07/2002
• Issued: 07/27/2004
• Est. Priority Date: 05/15/2000
• Status: Expired due to Term

• Current Assignee: Hansen Rubber Products Incorporated
• Original Assignee: Hansen Rubber Products Incorporated
• Inventors: Hansen, Steve
• Primary Examiner(s): Jules, Frantz F.
• Application Number:
  US10/275,665
• Publication Number:
  US 20030205626A1
• Time in Patent Office: 628 Days
• Field of Search: 238/84, 238/85, 238/106, 238/83, 238/95, 238/29, 238/30, 238/45, 238/28, 238/57, 525/240, 525/245, 525/2, 294/60
• US Class Current: 238/84
• CPC Class Codes: B29B 17/0042 for shaping parts, e.g. multilayered parts with at least one layer containing regenerated plastic
• CPC Class Codes: B29B 2017/042 Mixing disintegrated particles or powders with other materials, e.g. with virgin materials
• CPC Class Codes: B29C 48/00 Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor extrusion blow-moulding B29C49/04
• CPC Class Codes: B29C 48/06 Rod-shaped
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/13 Articles with a cross-section varying in the longitudinal direction, e.g. corrugated pipes
• CPC Class Codes: B29K 2007/00 Use of natural rubber as moulding material
• CPC Class Codes: B29K 2021/00 Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2105/26 Scrap or recycled material
• CPC Class Codes: B29L 2030/00 Pneumatic or solid tyres or parts thereof conveyor belts B29L2031/7092; drive belts B29L2031/7094; fourdrinier belts B29L2031/733
• CPC Class Codes: C08J 11/06 without chemical reactions
• CPC Class Codes: C08J 2321/00 Characterised by the use of unspecified rubbers
• CPC Class Codes: C08L 17/00 Compositions of reclaimed rubber
• CPC Class Codes: C08L 19/003 Precrosslinked rubber; Scrap rubber; Used vulcanised rubber
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: E01B 3/44 made from other materials only if the material is essential
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling

Abstract

A method for the manufacture of a railroad crosstie (90) from recycled rubber is disclosed. The rubber crosstie (90) has an expected life of between 30 to 60 years and can be made primarily of rubber crumbs obtained from stockpiles of discarded rubber tires. A feature of the invention is to produce a crosstie (90) having at least one longitudinal side incorporating a plurality of indentations for more effective engagement upon installation into a gravel bed to avoid slippage.

Claims

1. A method for producing a crosstie made substantially from recycled rubber comprising the steps of:

providing vulcanized recycled crumb rubber and natural recycled crumb rubber;

mixing by weight 10-35% said natural recycled crumb rubber and 65-90% said vulcanized crumb rubber to form a blend; and

adding a strength enhancing polymer to said blend, the amount of polymer to add is between 0.0-0.5% of the total weight of said blend;

milling said blend at between 240 degrees F. and 370 degrees F. (116-188 deg C.) to form an intermediate product;

extruding said intermediate product at between 240 degrees F. and 370 degrees F. (116-188 deg C.) to form an extrusion having a specific width and depth; and

,

thereafter cutting said extrusion at intervals to yield the croestie having the desired length.

2. The method of producing a crosstie according to claim 1 wherein said strength enhancing polymer is selected from the group comprising neoprene, polyethylene, urethane and ABS.

3. The method of producing a crosstie according to claim 1 further including a means to form a plurality of indentations in at least one side of said extrusion.

4. A crosstie made by an extruder from recycled rubber comprising:

A crosstie made entirely of an extrusion containing a blend of substantially no larger than 30 mesh (590 microns) recycled natural crumb rubber and recycled vulcanized crumb rubber in a weight ratio of between 10-35% recycled natural rubber to 65-90% recycled vulcanized rubber and a strength enhancing polymer selected from the group comprising neoprene;

polyethylene, urethane, and ABS, where said extrusion exits the extruder at a temperature of between 240-370 degrees F. (116-188 deg C.).

5. The recycled rubber crosstie of claim 4 wherein said crosstie has at least one longitudinal side has a plurality of indentations.

6. A crosstie made from recycled rubber comprising:

an extruded crosstie substantially made from a blend of recycled natural crumb rubber and recycled vulcanized crumb rubber where said crosstie comprises a weight ratio of between 10-35% recycled natural rubber and 65-90% recycled vulcanized rubber and where said crosstie further includes a strength enhancing polymer selected from the group comprising neoprene, polyethylene, urethane, and ABS.

7. The recycled rubber crosstie of claim 6 wherein said crosstie has at least one longitudinal side has a plurality of indentations.

8. A crosstie made from recycled rubber comprising:

a crosstie substantially made from a blend of recycled natural crumb rubber and recycled vulcanized crumb rubber where said crosstie comprises a weight ratio of between 10-35% recycled natural rubber to 65-90% recycled vulcanized rubber and a strength enhancing polymer selected from the group comprising neoprene, polyethylene, urethane, and ABS where said blend is subjected to a sufficient temperature and pressure to form said crosstie.

9. The recycled rubber crosstie of claim 8 wherein said crosstie has at least one longitudinal side has a plurality of indentations.