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-   -   aramid fiber (http://www.cyclebanter.com/showthread.php?t=255434)

Emanuel Berg[_2_] February 1st 18 04:58 AM

aramid fiber
 
IIUC aramid fiber is when you not only use
carbon to reinforce the plastic (which is
ordinary carbon or CFRP) you also use aramid
("aromatic polyamide") which is synthetic
polymer perhaps in the nylon rope sense, and
this carbon/aramid reinforcement combination is
what makes the material "composite", and this
material has been commercialized using
para-aramid under the name Kevlar.

Anyone ever make a bike out of it?

I just saw it on a hockey stick, the
CCM RIbcore 40K. Unfathomably, they didn't put
the weight on it (the stick), but I checked it
myself and it weighs 435g, compared to my old
stick, which is wood with glass fiber on the
blade only, and that is 805g (including tape).
Also, the new stick was 1299 SEK
(1299.00 SEK ~= $164.97 | £116.13 | €132.76)
which in the hockey world isn't expensive.

So the material seems to be cheap and light
enough, perfect for bikes in other words?
BTW how much is a typical medium-level CFRP
frame in grams and dollars? We can compare the
expensive bike world with the expensive hockey
world...

--
underground experts united
http://user.it.uu.se/~embe8573

AMuzi February 1st 18 03:24 PM

aramid fiber
 
On 1/31/2018 9:58 PM, Emanuel Berg wrote:
IIUC aramid fiber is when you not only use
carbon to reinforce the plastic (which is
ordinary carbon or CFRP) you also use aramid
("aromatic polyamide") which is synthetic
polymer perhaps in the nylon rope sense, and
this carbon/aramid reinforcement combination is
what makes the material "composite", and this
material has been commercialized using
para-aramid under the name Kevlar.

Anyone ever make a bike out of it?

I just saw it on a hockey stick, the
CCM RIbcore 40K. Unfathomably, they didn't put
the weight on it (the stick), but I checked it
myself and it weighs 435g, compared to my old
stick, which is wood with glass fiber on the
blade only, and that is 805g (including tape).
Also, the new stick was 1299 SEK
(1299.00 SEK ~= $164.97 | £116.13 | €132.76)
which in the hockey world isn't expensive.

So the material seems to be cheap and light
enough, perfect for bikes in other words?
BTW how much is a typical medium-level CFRP
frame in grams and dollars? We can compare the
expensive bike world with the expensive hockey
world...


Aramid-Kevlar strands in carbon frames was a breakthrough
concept in 1986:

https://en.wikipedia.org/wiki/Kestrel_USA

better known in other products:
https://www.youtube.com/watch?v=Hyn7eKfQXPg


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



John B.[_3_] February 2nd 18 02:35 AM

aramid fiber
 
On Thu, 01 Feb 2018 04:58:54 +0100, Emanuel Berg
wrote:

IIUC aramid fiber is when you not only use
carbon to reinforce the plastic (which is
ordinary carbon or CFRP) you also use aramid
("aromatic polyamide") which is synthetic
polymer perhaps in the nylon rope sense, and
this carbon/aramid reinforcement combination is
what makes the material "composite", and this
material has been commercialized using
para-aramid under the name Kevlar.

Anyone ever make a bike out of it?

I just saw it on a hockey stick, the
CCM RIbcore 40K. Unfathomably, they didn't put
the weight on it (the stick), but I checked it
myself and it weighs 435g, compared to my old
stick, which is wood with glass fiber on the
blade only, and that is 805g (including tape).
Also, the new stick was 1299 SEK
(1299.00 SEK ~= $164.97 | £116.13 | €132.76)
which in the hockey world isn't expensive.

So the material seems to be cheap and light
enough, perfect for bikes in other words?
BTW how much is a typical medium-level CFRP
frame in grams and dollars? We can compare the
expensive bike world with the expensive hockey
world...


I suspect that it may be at least partly to the loading of the device
(the direction and amount of force applied to a device). Kevlar, that
you mention has tremendous tensile strength - The specific tensile
strength (stretching or pulling strength) of both Kevlar 29 and Kevlar
49 is over eight times greater than that of steel wire. But on the
other hand it has very poor compressive strength (resistance to
squashing or squeezing). Rather difficult to design a three
dimensional device using a material that has strength in only one
direction :-)
--
Cheers,

John B.


Emanuel Berg[_2_] February 2nd 18 03:19 AM

aramid fiber
 
John B. wrote:

I suspect that it may be at least partly to
the loading of the device (the direction and
amount of force applied to a device). Kevlar,
that you mention has tremendous tensile
strength - The specific tensile strength
(stretching or pulling strength) of both
Kevlar 29 and Kevlar 49 is over eight times
greater than that of steel wire. But on the
other hand it has very poor compressive
strength (resistance to squashing or
squeezing). Rather difficult to design
a three dimensional device using a material
that has strength in only one direction :-)


Easy. Make a new composite material,
Kevlar/Kevlar, and put them perpendicular to
each other :)

--
underground experts united
http://user.it.uu.se/~embe8573

AMuzi February 2nd 18 03:26 AM

aramid fiber
 
On 2/1/2018 8:19 PM, Emanuel Berg wrote:
John B. wrote:

I suspect that it may be at least partly to
the loading of the device (the direction and
amount of force applied to a device). Kevlar,
that you mention has tremendous tensile
strength - The specific tensile strength
(stretching or pulling strength) of both
Kevlar 29 and Kevlar 49 is over eight times
greater than that of steel wire. But on the
other hand it has very poor compressive
strength (resistance to squashing or
squeezing). Rather difficult to design
a three dimensional device using a material
that has strength in only one direction :-)


Easy. Make a new composite material,
Kevlar/Kevlar, and put them perpendicular to
each other :)


Kevlar/Aramid excels in tensile strength. Maybe you should
review this:
http://www.instron.us/en-us/our-comp...s/tensile-test

but it's unremarkable in shear.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



Emanuel Berg[_2_] February 2nd 18 04:09 AM

aramid fiber
 
AMuzi wrote:

Kevlar/Aramid excels in tensile strength.
Maybe you should review this:
http://www.instron.us/en-us/our-comp...s/tensile-test


OK, seems like a lot to digest but no one said
it was supposed to be easy, right?

but it's unremarkable in shear.


One better double-check the direction of the
fibers before pulling on the bulletproof
vest :)

BTW I wonder if this is why it is used in
hockey sticks, skis, etc. "Hard and flex at the
same time", remember?

The hockey stick for sure cannot be pulled any
longer than its original 60 inches (~152cm) but
one can budge it on the middle leaning on it
and giving it just a small extra push.
This property in the hockey world is called,
with this instance as an example, "flex 85"
(which is pretty hard, for a strong but
medium-sized player). I'm unsure if this is
just a digit the manufacturers use or if it has
some scientific ground as well WRT
the material.

--
underground experts united
http://user.it.uu.se/~embe8573

John B.[_3_] February 2nd 18 04:27 AM

aramid fiber
 
On Fri, 02 Feb 2018 03:19:07 +0100, Emanuel Berg
wrote:

John B. wrote:

I suspect that it may be at least partly to
the loading of the device (the direction and
amount of force applied to a device). Kevlar,
that you mention has tremendous tensile
strength - The specific tensile strength
(stretching or pulling strength) of both
Kevlar 29 and Kevlar 49 is over eight times
greater than that of steel wire. But on the
other hand it has very poor compressive
strength (resistance to squashing or
squeezing). Rather difficult to design
a three dimensional device using a material
that has strength in only one direction :-)


Easy. Make a new composite material,
Kevlar/Kevlar, and put them perpendicular to
each other :)


Given that the New Age thinking seems to be that weight is secondary
in importance to streamlining maybe it is time to return to steel
frames. Aerodynamically designed, of course.

--
Cheers,

John B.


AMuzi February 2nd 18 02:32 PM

aramid fiber
 
On 2/1/2018 9:09 PM, Emanuel Berg wrote:
AMuzi wrote:

Kevlar/Aramid excels in tensile strength.
Maybe you should review this:
http://www.instron.us/en-us/our-comp...s/tensile-test


OK, seems like a lot to digest but no one said
it was supposed to be easy, right?

but it's unremarkable in shear.


One better double-check the direction of the
fibers before pulling on the bulletproof
vest :)

BTW I wonder if this is why it is used in
hockey sticks, skis, etc. "Hard and flex at the
same time", remember?

The hockey stick for sure cannot be pulled any
longer than its original 60 inches (~152cm) but
one can budge it on the middle leaning on it
and giving it just a small extra push.
This property in the hockey world is called,
with this instance as an example, "flex 85"
(which is pretty hard, for a strong but
medium-sized player). I'm unsure if this is
just a digit the manufacturers use or if it has
some scientific ground as well WRT
the material.


I'm sure Frank could discuss tension and compression in a
beam better but here you go:

http://people.virginia.edu/~pjm8f/en...and_strain.htm

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



[email protected] February 2nd 18 06:31 PM

aramid fiber
 
Today carbon fiber.

Unbelievable kayak paddle$

One swing = x 1000 swings =

I would prowl new canoe lots rapping on hulls checking new claims

See CF custom canoe

https://www.google.com/search?q=aram..._6ZH4Ag_1:6 4

Emanuel Berg[_2_] February 8th 18 01:16 AM

aramid fiber
 
Maxxis Detonator 23x622 clinchers have Kevlar
wire. Making the tire more straight/strong
and/or lighter while making the bike
more expensive?

--
underground experts united
http://user.it.uu.se/~embe8573


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