Elastic cord replacement material
Elastic cord replacement material
(OP)
I have an application where I am in need of an elastic cord. Similar products on the market are the Goody elastic cords (http://www.goodycomfort.com/main.taf?p=1,4) used which are used as hair bands, and are only available in a few sizes. I have considered using an o-ring as various standard sizes are available for a 1/8" (.125) cross-section width. The o-ring would need to have a good resilience (rebound), and weather resistance. From the chart in an o-ring products book Neoprene appears to be the best choice of material as natural rubber is rated poor in weather resistance.
As rubber bands typically have a 35A durometer, and several o-ring manufacturers have the capability of manufacturing 40A durometer o-rings, this would appear to be a good alternative to the Goody elastic cords. The application is for a consumer good product, and the typically bungee cords are too high in cost.
If anyone else has other elastic cord / material recommendations, I would be interested in hearing about those as well.
As rubber bands typically have a 35A durometer, and several o-ring manufacturers have the capability of manufacturing 40A durometer o-rings, this would appear to be a good alternative to the Goody elastic cords. The application is for a consumer good product, and the typically bungee cords are too high in cost.
If anyone else has other elastic cord / material recommendations, I would be interested in hearing about those as well.





RE: Elastic cord replacement material
Mike Halloran
Pembroke Pines, FL, USA
RE: Elastic cord replacement material
I am looking to use an elastic cord in an assembly to join parts together. An example would be a portable bicycle pump to its mounting bracket to prevent it from slipping-off (not the actual application). Are there any torus-shaped bungee cords on the market?
The hair band bands are too short, and the head wraps are too long in regards to the O.D. As o-rings are available in various O.D. or I.D. sizes (ex: AS 568A-226,-242,-258, etc.), I have not yet determined the size needed. If will depend on the design of the injection-molded plastic parts.
As I mentioned, the elastic cord would need to be low-cost, and available as an off-the-shelf component if possible. With an o-ring, this may requiring a special order due to possible need of a lower durometer material. The typical o-ring durometer of 70A will not have the degree of elasticity as required. I am open to hearing about other suggestions.
RE: Elastic cord replacement material
If your product requires more than about 10 to 20% stretch on a frequent or continuous basis I would recommend shock cord.
RE: Elastic cord replacement material
Some stores carry a very good cross section sizes and shapes.
Here is a site that has round cord and loop
http://elasticconnections.com/loops.html
RE: Elastic cord replacement material
The linear bungee / shock cord typcially found in stores have hardware (hooks, balls, barb, etc.) on the ends of a linear cord which may not be needed for my application. This is the reason why I was looking at the Goody headwraps is the ends are joined together without hardware in a similar fashion as an o-ring. However, the ID size is not correct for my purpose unless other sizes are available in the range of a 3 to 4 inch I.D., and 1/8 inch cross-section (similar o-ring size: AS 568A-234 to AS 568A-242).
Some other possible manufacturers I located are:
* LexcoCable: http://www.lexcocable.com/bungee-cords.html
* Phoenix Roper & Cordage: http://www.phoenixrope.com/elastic.html
* American Cord & Webbing (ACW): http://www.acw1.com/
* HNW: http://www.hnwelastic.com/products.htm#cords
If you know of any other manufactures that provides off-the-shelf elastic shock cords close to the sizes I had previously mentioned, then let me know. I need to get some samples to test in a prototype assembly.
I had tried a local hobby store but nothing was close ti what I was looking for was available.
RE: Elastic cord replacement material
You also might look at SBR tubing which I believe is bondable
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http://www.kentelastomer.com/
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Here is a source of SBR and also rubber bands.
http://www.aerorubber.com/tubing.htm
RE: Elastic cord replacement material
Here is a product similar to what I am looking for from UMX Inc. Lanyard Supply:
* LY-WR-401EC 1/8"(D) x 14"(L) Elastic Round Cord (approx 4 ½" I.D.): http:
Not sure if this material would classify as an elastic shock cord, but I will try to get some samples for evaluation.